Mains Operated LED Circuit

This is a modified version of the circuit Super bright LED Night Light published here. This circuit is submitted by Mr. Seetharaman and its full credit goes to him.

This is the circuit of a well tried and reliable 230 Volt AC mains operated 24 LEDs (super bright 50mA LEDs). While practically compare the brightness between this circuit and 11watts tube, the LED light is much better. The layout is made in such a way, you get uniform illumination. A photograph of the cicuit is also given in this post.

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555 Responses to “Mains Operated LED Circuit”

  • chand says:

    how to choose 100 ohms in series??explain me sir

  • Harish says:

    How do you define 1uf capacitor for 24 LEDs? if I use lee Leds then what will happen? if I use 30mA & 3.3V rated 5mm LEDs then?

  • chandana says:

    i have super bright led 16, and normal blue 4, red 4, led s. is it good? or send me resistor name for normal led + or – side.

  • guhan says:

    hi sir,
    i am regular reader and follower of you circuit…but i have a doubt the is it necessary for to calculate all the possible value in a circuit….because i have built two circuit without any calculation and i have achieved the output….
    sir please guide me as your student…and my mail id is guhanvijay92@gmail.com……………
    by one of your student….thank you sir

  • Neville says:

    Dear sir,
    I am a bit confused about the normal AC value say 230V and it’s RMS value of about 325V in the calculation of the poly cap value in the circuit.Is it not advisable to calculate the capacitor value using the RMS value instead of 230V?
    Also why not use a 400V rated smoothing cap all the time instead of 160V towards the safety of the LEDs?

    A Quick reply is very much appreciated.
    Thanks in advance

    Neville

    • Seetharaman says:

      Since 160 volt is sufficient and quite compact in size as the space is limited it was preferred. if space available is plenty you can use 400 volt s capacitor for filtering. For 1uF it should be 400 volt DC working voltage or 250 volt ac working voltage. as the voltage across can reach the peak voltage of the applied ac rms value, hence 400 V DC is chosen.

  • Saiful says:

    Sir,
    I’ve made several ckt using ur ideal ckt.
    At today’s morning, I’ve made a ckt which output is 9V,200mA. When I connect it with 220V AC, it was getting burn. Quickly I disconnect the ckt. Sir I think the problem is with the filter capacitor or other I don’t know.
    Now sir pls tell me about the modification ASAP.

  • Bipeen says:

    Dear Sir,

    I want to make 10 nos.(1 WATT,350 mA) LED bulb. What modifications I have to do in above circuit? How to calculate electrolytic capacitor value and resistor values for this design?

    Can i used electrolytic instead of the polyester?

  • Bipeen says:

    Dear Sir,

    What modifications to be made if i’m using Min:3.0V Max: 3.6V, 350mA power LED?

  • Bipeen says:

    Dear Sir,

    Please help me on A dim glow from lamp after switch off.

    Please help me on that..

    Thanks in advance.

    • Bipeen says:

      Dear Seetharaman Sir,

      Please reply.

      • Seetharaman says:

        This is due leakage current in your fittings. this will not affect the operation of the circuit.

        • Bipeen says:

          Dear Sir,

          I checked the circuit again but i can’t find the leakage of current. I am using 1OOuf 400v cap.

          Please help me on that.

          Thanks in advance.

          • Seetharaman says:

            Remove power supply to the LED light if no glow. you are having the control switch in neutral instead of in live. Please do the necessary correction.

  • Paula Paula says:

    Good afternoon.

    Its me again, i am sorry to bother you again, you already gave me the specs for 127vac, but my leds are not 50ma but 20ma, do i have to change the values you alredy gave me.

    Thankyou in advance, kind regards.

    Paula

  • james says:

    hi i want to glow more than 500 white led… is 1.2uf is enough..
    wat r the changes in components.

  • paula paula says:

    Good afternoon.
    It is a great circuit, congratulations. I am trying to build the same circuit but iam inexperienced in calculations, what would be the values if i am using 25 standard 20ma 3.5v blue leds at 127vac 60hz?
    Thank you in advance. Kind regards

    • Seetharaman says:

      Hi Paula for 127volts 60Hz operation, you can use the above circuit with 1uF reduced to 0.82uF 250 volts and 10uF can be 250 volts DC. other components can be same.

    • Seetharaman says:

      for 20ma the components will change, you have to reduce the capacitor to 0.9uF (use 0.56uF and 0.33uF in parallel) other modifications as suggested earlier are ok.

  • bhaskar says:

    Hi, I’ve 1w 300ma LED. want to prepare the above circuit, what is the necessary change should I made. I’m a amature and have only basic knowledge of electronics. Already prepared some of your amplifier circuits and willing to assemble 100w subwoofer soon.

    • bhaskar says:

      sorry the LEDs are 1w 350ma, not 300ma.
      Thanks.

      • Seetharaman says:

        For 24 nos 350mA LEDs 1uF should be increased 6.2uF and 100 ohms should be reduced to 33 ohms 5Watts 10uF should be increased to 100uF 400 volt. all other components can be same. Still I recommend you to go for 3.3 volt SMPS of required current and connect all LEDs in parallel, which will be more reliable.

  • gabyh says:

    Hy i have made a 2 circuit with 38 and 39 leds and i use a 0,47uf/400v and 10uf/250 for last capacitor and the resistor at 100ohm/1w
    From mai calculation at 3,3v/25mA ..for 240v AC, 38×3,3=125,4v; 240-125,4=114,6v need to drop. Resistance 114,6/0,02=5730ohm so C=1/xc*Ѡ or C=1/2pi*f*xc so C=1/6,28*50*5730 and 10−6 /1799220 = 0,5557uf.
    So what is the best choice for C 0,55uf or 0,47uf
    and for 10 leds at 3,3v/25ma C=0,307uf at 240v or 0,404uf at 230v
    In a old post you respond …at 67 leds/20mA/3,2v need 0,82uf but, from my calculation c=1/6,28*50*780 C=1/244920 so c=0.0000040829658664Farad=(4,08uf)
    or 24led/25mA need 0,39uf and ofter my calculation need 0.519uf
    So where is my mistake? how to calculate value of C for 67leds or how to calculate with a large number of leds because the voltaje drop by led it’s so big and mains supply is only 230v. can you detail calculation because i don’t understand if i use 85, 90, 100, 120 leds.?
    i don’t understand
    regards

    • Seetharaman says:

      Hi the basic is, a rectified output for a given RMS AC in is, voltage RMS in X root 2 (1.414) now you go ahead with all your calculations. That is 325 volt DC for 230V RMS in.

  • Saiful says:

    Dear Seetharaman Sir,
    I’ve made this ckt. It’s awesome. All the component are working so nice. Even any of components were heating up.
    From the comment I come to know that with supply and without load the ckt might be burnt. Now my question is:
    If any of LED got fused & got disconnect any of LED then the whole ckt will be open. Then what will happen to the ckt? will it be brunt or its any component?

    • Seetharaman says:

      to avoid this problem you kindly replace 10uF 160 volt with 400 volt. now it will take care of open circuit voltage of 325volt approx with 230 volt AC input.

  • Subrata Mahata says:

    WASEEM, your calculation(October 21, 2013 at 8:38 am) is right but the formula gives capacitance in F(Farad). To give microfarad multiply it with 1000000, that means 1F=1000000uF

  • Saiful says:

    Dear sir,
    I’ve calculate the value of polyester capacitor. I’ve got 730,068 pF(considering a circuit with 4 LED, each 3 V, & 50 mA).
    For this value, the nearest standart value is 684K or 704K. Now sir please suggest me that,
    1. Is my calculation is correct? If wrong what it should be?
    2. Do I need to change other component of the circuit? If yes then, What will the change of discharging resistor, current limiting resistors & filter capacitor value be?
    Sir, I’m waiting for your valuable replay & help me out not to burn or blast my components by giving correct value.
    Thank your so much.

    Your obedient,
    Saiful

  • raj says:

    Hi Mr. Seetharaman,

    what parts I need to change if i want to build this circuit using 12 nos white leds (100ma)? Thanks.

  • Saiful says:

    Dear Seetharaman Sir,
    Thanks for ur hard work, I mean rply to all with care. It’s very good of u I think. Sir, now I’ve to made a ckt with 4 led. Each r 3V, 50mA. So pls sir help me out. Tell me about the modification. Thank Sir.
    From,
    Saiful

  • gabyh says:

    Hy i have made a 2 circuit with 38 and 39 leds and i use a 0,47uf/400v and 10uf/250 for last capacitor and the resistor at 100ohm/1w
    From mai calculation at 3,3v/25mA ..for 240v AC, 38×3,3=125,4v; 240-125,4=114,6v need to drop. Resistance 114,6/0,02=5730ohm so C=1/xc*Ѡ or C=1/2pi*f*xc so C=1/6,28*50*5730 and 10−6 /1799220 = 0,5557uf.
    So what is the best choice for C 0,55uf or 0,47uf
    and for 10 leds at 3,3v/25ma C=0,307uf at 240v or 0,404uf at 230v
    In a old post you respond …at 67 leds/20mA/3,2v need 0,82uf but, from my calculation c=1/6,28*50*780 C=1/244920 so c=0.0000040829658664Farad=(4,08uf)
    or 24led/25mA need 0,39uf and ofter my calculation need 0.519uf
    So where is my mistake? how to calculate value of C for 67leds?
    i don’t understand
    regards

  • Neville says:

    Sir,
    I am a medical doctor and a newcomer to the electronics field as a hobby.
    Your forum I must say is very educative and practical. I built the above circuit and is working very well over the past few weeks. I wish to build one with 69 straw hat type bright LED s. Could you kindly let me know the component specs please. I thank you very much in advance and for this very enjoyable forum.
    Thank You

    • Seetharaman says:

      Hi The straw hat LEDs require 3.2 volt at 50mA component requires changes are 1uF to 2uF and 10uf 160 volt to 22uF 400 volt

  • Neville says:

    Dear Mr. Seetharaman,
    What changes are reqd. for 69 25Ma LEDs in series and to get a good light output? Thanks a lot in advance

  • Joy Antony says:

    Sir.
    Can you suggest a reliable driver circuit-capasitive/resistor circuit
    to drive 1 Watt high power leds in TEN numbers.
    It is highly appreciated if you could post me as soon as possible.
    Thank you,

    • Seetharaman says:

      1watt LED requires 3.2 volt at 330mA for 10LEDs in parallel a power pack of 3.2 volt 3.3 amps SMPS power pack. In the above circuit 1uF to be increased to 2nos 2.2 uF in parallel. and 10uF 160 volt to 100uF 400 volt. both 100 ohms to 33 ohms 5 watt. But I do not recommend a capacitor power pack instead my strong recommendation will be for a switched mode power supply.

  • Anupam says:

    Sir,
    Please let me know how to design the resistors in this circuit(400K & 100 ohms)?

    • Seetharaman says:

      Hi Anupam 2 100 ohms are for limiting the surge current through the circuit. it is limited to 1 amp approx with 200 ohms. The 470K is for discharging the 1uF capacitor. A dim glow from lamp after switch off can be reduced. This value cannot be reduced very much as it is likely to pass excess current through the LEDs.
      In the event of plugging out the lamp and touching the lamp plug may give a nasty shock due to the capacitor charged energy.

  • pankaj says:

    what is the life spam of this led circuit

  • Arnab Dhua says:

    How to calculate the value of surge current limiting resistors(as in the above circuit it is two 100ohms)?

  • Arnab Dhua says:

    Thank you sir.

  • Arnab Dhua says:

    Sir how to calculate the value of 10uf,160v capacitor?

    • Seetharaman says:

      The capacitor should be at least 10 times the supply capacitor such that it takes care of the inrush current from 1uF to protect LEDs from large surge current, hence 10uF is selected. For minimum ripple across the LEDs for professional applications it should be at least 100uF for least ripple. But for our applications 10uF 400 volt will do. if 100uF 400 is available and space is available you can use 100uF 400 volt for absolute flicker free illumination.

      • Arnab Dhua says:

        Sir in the picture it is 10uf 160v.So it will be 160v or 400v?

        • Seetharaman says:

          160 volt will do if the load is not getting disconnected. If the load gets disconnected due to dry joint in the circuit then the capacitor will get a peak voltage of 350 volt, a 160 volt capacitor may get damaged, hence 400volt is preferred voltage value.

  • MANAS says:

    dear sir,
    i have 86 led’s circuit with 4.7uF CAPACITER AND 822J POLY CAPACIER, 4 NOS 1N4007 RECTIFIRE, 6.8k ohms resister,560k
    ohms resister, 820k omh resister. i connect all thigs but the brightnes of led is low. pls what is the problem? and pleas send me 57 led’s and 100 led’s circuit diagram (manasmum(at)gmail.com.
    thank you

    • Subrata Mahata says:

      You have not mention LED current and Voltage. I take it 50mA and 3V.
      86 LED Drop 86×3=258V. But yours mains supply is 230V. How can it glow brightly?
      And your capacitor 822J =8200pF=0.0000000082F ,
      it reactance=1/2π×50×0.0000000082=388182.79Ω
      and it drop the voltage=388182.79×0.05=19409V.
      Calculation
      I=Led Current(in A, basically LED Current in mA ), V= Led voltage
      Voltage drop by Leds = No Of Led × I
      Remaining Voltage =230- Voltage drop by Leds
      C1 drop the Remaining Voltage
      Xc= Remaining Voltage/I
      C1= 1/2πFXc (will get in Farad, convert it to uF by multiplying 1000000)

      • manas says:

        thank you sir

      • gabyh says:

        you make a mistake in calculation…Voltage drop by Leds = No Of Led × V not for I so how to calculate for 86 leds?? because 86×3=258 and remaining voltage is negative if 230-258=(-28)??? sau what is the remaining voltage drop by C1? (-28V)? how to calculate with a large number of leds because the voltaje drop by led it’s so big and mains supply is only 230v. can you detail calculation because i don’t understand if i use 85, 90, 100, 120 leds.
        How can use the clasic formula R=V/I or Xc =V/I where V= V of supply -V drop by led and I current of led?

        • Seetharaman says:

          Since it is RMS voltage is the input to your bridge rectifier. The basic is RMS X root 2(1.414) is the DC output. This basic you have left that is the problem in your calculation.

  • Osama Habbob says:

    Dear sir
    i want to build a similar circuit using 40 LED with 150 mA current
    what are the changes that have to be made for this circuit
    with reagrds
    or should i use it as it is

  • M. Z. ISHRATH says:

    Dear Sir,

    Can you please indicate me the max numbers of straw hat LEDs (3V and 20MA)that could be used for 1uf and 0.47uf polyester caps respectively in this circuit.

  • nisanth says:

    sir,

    how to construct a 45 no’s hi bright white led and 5 no’s red led (only red led blinking) in AC mains. I wants to construct in series circuit.

  • Siddharth says:

    Please help me understand the full circuitry
    Mainly th input cap 1uf 400V and the calcuations which WASEEM AHMAD did R= v÷i. 153÷0.05= 3064 ohm if the calculation is correct where is the R value located in the circuit

    • Seetharaman says:

      Hi Siddharth. we are using the Xc of the capacitor to drop the voltage. if you use resistance it will dissipate V X I power. here the capacitor voltage lags by 90deg the current through it, hence the dissipation is zero. Hence the real wattage consumed is the power consumed by LEDs only.

    • Seetharaman says:

      Hi
      using the Xc of the capacitor to drop the voltage. if you use resistance it will dissipate V X I power. here the capacitor voltage lags by 90deg the current through it, hence the dissipation is zero. Hence the real wattage consumed is the power consumed by LEDs only.

  • Gaurav says:

    Sir can u plz tell me the requirment of resistance accross capacitor, and how it’s rating decided.

    • Seetharaman says:

      It is just to discharge the capacitor when you switch off the lamp. if you do not connect, in the event of removing from the holder and accidentally touching the terminals of the light you will get a nasty shock. Should be capable discharging the capacitor in just few seconds.

  • WASEEM AHMAD says:

    Hi
    well I ve studied from arts stream learning about elec. components is my hobby. and I make grammatical misteks in english so plz ignore them.
    well gonna tell u 2 calculate the main component of this circuit polyester cap. with e.g.
    in the above circuit
    we gonna glow 24 leds those are 3.2v 0.05 amp in 230v ac.
    so 24×3.2= 76.8v we require to glow r leds n 230- 76.8= 153.2
    so we need to drop 153.2v. now we ll calculate the resistance by
    R= v÷i. 153÷0.05= 3064 ohm
    now cap. right formula is
    C= 1/2pi × f × xc

    C for capacitance in farad
    F for frequency of suply in hertz
    XC for capacitive reactance in ohm
    one PI is equal to 3.14….. 2pi is 6.28…
    so 1/2pi= 6.28 × f= 50 × XC = 3064 OHM
    1/6.28×50×3064= something like 962096 now
    1/962096 = 0.00000103…… uF still confuse ok multiply 0.00000103….to 1000000= 1.0….this is one microfarad

    hit thanks

    • Seetharaman says:

      Hi Waseem your calculations are correct but in final calculation it is 1 / (2pi X f X Xc) all should come in denominator. where F is in Hz, Xc is in ohms and capacitor value in Farades ( 1000000 uF) so will get 1.039uF the nearest standard value is 1uF.

  • Dushan(srilanka) says:

    Thank’s dear

  • Ombeer says:

    Hello Sir,

    Which LED I use for best result.

  • Kaushal says:

    Hello,

    I want to make 10 nos.(1 WATT,350 mA) LED bulb. What modifications I have to do in above circuit? How to calculate electrolytic capacitor value and resistor values for this design?

    Thanks,
    Kaushal.

  • Mohan says:

    Hello,

    I want to make 10 nos.(1 WATT,350 mA) LED bulb. What modifications I have to do in above circuit? How to calculate electrolytic capacitor value and resistor values for this design?

    Thanks,
    Mohan.

  • robert says:

    sir can i used electrolytic instead of the polyester?

  • a.satish says:

    dear sir this is satish.

    sir i am a fresher .i want to design the led desigening please give me the suggestion .for 10 no`S LED designing.AND circuite

  • mehul says:

    sir,
    tell me detail calculation about RC parallel block. how it work in this circuit. how to calculate Watt. i need calculation about section that is before bridge.

  • mehul says:

    sir,
    tell me detail calculation about RC parallel block. how it work in this circuit.

  • Hello Mr. Seetharaman
    I want to make 3 to 5 nos. LED on main operated at home.
    how can i do it.
    please suggest.
    Thnx.
    Pravin C

  • Pravin C. says:

    Hello Mr. Seetharaman

    I want to make 3 to 5 nos. LED on main operated at home.
    how can i do it.
    please suggest.

    Thnx.

    Pravin C

  • Thanks………… a lot.

  • Sir,
    I have made a Mains Operated LED Circuit using 46 leds and they are working fine but can u please help me with the modification required to make 2 circuits one using 77 and second with 110-120 white leds of 3.2v,25mA i am a new follower of your site i wish u will help me thanks.

    • Seetharaman says:

      hi danda for 77 leds of 3.2 volts 25 ma use 1.2uf instead of 1uf 400volts no other changes are required.
      you can use 100 leds in the above circuit just link 1uf 400 volt no capacitor required, other components are required no change.

      • Sajan says:

        Sir,

        Am a new follower with little knowledge in DIY projects. Your reply to Soumitra Danda for 100 LEDs you have advised him to use a 1uf 400V cap is to be used and no capacitor is required for 100 LEDs. I guess its a typo as 100 LEDs are being used so there’s no voltage drop is required right? Also each LED will consume 3.2V each so how will all 100 LEDs glow in optimum brightness as the supply voltage is only 220V max? Or are you suggesting this for the better life span of the LEDs? Can you elaborate on this? Am also planning to build this soon for decorative purpose. How about 68-70 LEDs in a circuit for the optimum brightness? Pls be in detail.

        • Seetharaman says:

          Hi If you rectify 230volt ac and across the filter capacitor the DC available will be AC RMS X root2 That is 1.414 X 230 That is 325 Volt DC. Hence for 100 LEDS of 3.2 volt you do not require any dropping capacitor. For 77 LEDs you have to drop 325 – 246.4 volt hence 1.2 uF.

      • Arnab Dhua says:

        for 77 leds voltage needed is (77×3.2)=246.4volt Then why to add 1.2uf capacitor..didn’t understand this.sir please explain.

  • Sir,
    I have made a Mains Operated LED Circuit with 46 white Piranha leds of 3.2v,25mA,angle 110 degrees and now i wish to make a few other circuits using 77 leds and 110-120 leds max, sir please help me with the changes required to be made to make this 2 different kind of circuits, i am very interested in building the above mentioned circuits please help me.

  • R P Singh says:

    Dear Mr. Seetharaman,

    I have built the LED circuit exactly as demonstrated by you for 24 LEDs in circuitstoday.com. I have used bridge rectifier instead of 1N4007. During testing, invariably, 2-4 LEDs go blank and have to be replaced. When I checked the current, it was 46.8 mA. I have used 5 mm white LEDs with 7 mm height (focussing type).

    I have calculated the resistance to reduce current to 20 mA and it comes to 4000 Ohms. This is not a standard resistor. Please guide me. The lights have dimmed considerably after 12 days of use.

    • Seetharaman says:

      mr singh the circuit is meant for 60ma high bright 4 pin white leds. for two pin focus type tor sizes from 3mm to 10mm led is just 25ma only. hence use the same circuit just replace 1uf 400 volt with 0.33uf 400 volt. that is all the modification required. ensure the leds have enough ventilation.

  • Subhankar Sarkar says:

    Sir,
    If somebody use 150ma(8mm .5w)led instead of 50ma led. You have told that he has to decrease the value of 100ohms .5 watts to 33ohms 1 watt of both the resistors and to increase the value of that capacitor 1uf to 2.5 uf and the capacitor 10uf 160v to 47uf 350v. What will be the power consumption? Is it (3.2 X .15 X 24) = 11.52 watt? And is it better than 30 watt cfl? And if some body uses 8 pieces of 150ma(8mm .5w)led instead of 24 50ma leds is there any change will be required? And what will be the power consumption? is it (3.2 X .015 X 8)= 3.84 watt and is it better than 11 watt cfl? Please reply. Thanks in advance.

    • Seetharaman says:

      hi sarkar you are correct about consumption and compared correctly with cfl bulbs, you have to add dissipation of the resistances also

  • Nalin says:

    Sir, Thank you so much for this valuable circuit. Please let me know that can we use half-wave power supply instead of full-wave (Bridge rectifier). Will it saves the power consumption of this circuit? Is it dis-crease the brightness of the lamp. Waiting for your kind response ? thank you so much

  • goutam says:

    can any body share idea about how to make a LED bulb. for 230 volt supply .

  • Rizwan says:

    Dear Mr. Seetharam,

    I have successfully completed the above circuit using 0.68uf 400v. The voltage across the LEDs is 82volts and consuming 30ma.

    Since 1uf was giving 87 volts and LEDs were consuming 40ma but my LEDs need 30ma.

    On the mains when I checked it was consiming 37ma which means 8.5watt

    I again checked the LEDs, they consume 30ma 82volts which means 2.5watt

    No components are heating up, everything working fine. I have used good quality 1N4007 to make the bridge, then what is consuming the missing 6watts.

    Please advice

    Rizwan

    • Seetharaman says:

      Hi Rizwan you are calculating apparent power that is total voltage multiplied by current. The active power is only LEDs consumption. As the voltage lags by 90 deg to current in a capacitor the power consumed by the capacitor is zero. If you use an accurate low power meter which ca measure up to 0.1 watts you can really see the consumption is just 2.5 watts. If say capacitor is consuming the balance power of 6 watts, it should get heated up!?. Whenever you calculate AC power you have to include in the multiplication voltage, current and power factor. Hope it is clear.

      • Rizwan says:

        Dear Mr. Seetharam,

        Thanks for your reply on the basis of which I studied the power factor (apparent and real power)

        You are absolutely right, I am measuring the miliamps and multiplying by voltage which is real power for DC but for AC it is apparent due to power factor.

        I don’t have a power meter but now I am convinced that the circuit is consuming 2.5watts and also your view that anything consuming 6 watt would heat up.

        I have learned a lot from you and for me knowledge is precious than anything. I am so very grateful to you.

        I have problem with my inverter which I think you can solve. If you give me your email I can send the details of the circuit and my findings so far, along with the pics.

        Once again Thanks a lot!

  • KENNY says:

    hi sir, can i replace the led to 3x1w led?
    any modification on the circuit?
    the 4 diode what is the rating for the component?
    can i use 1n 4007?

  • Novice says:

    Sir,
    you have used 24 leds each of 3.2Volts in series that would require 3.2×24 = 76.8 Volts- after the bridge.
    How do u get 76.8 volts or something close to that value after the bridge?
    what is the voltage at both sides of the bridge and how?

    please reply

  • Novice says:

    Sir,
    you have used 24 leds each of 3.2Volts in series that would require 3.2×24 = 76.8 Volts- after the bridge.
    How do u get 76.8 volts or something close to that value after the bridge?
    what is the voltage at both sides of the bridge and how?

  • manish says:

    sir 160v 10 microF capacitor heat up soon as switch on the circuit
    its normal or any problem in capacitor ? please help.

  • andleep says:

    Sir what is the meaning of poly in 1uF 400V Poly:

  • cooool says:

    Sir please explain me how to calculate capacitor for led circuits

  • cooool says:

    Sir I am beginner in electronics please explain me why we use capacitor in this circuit we can use only resistor by calculating resistor ohms law R=V/I and how to calculate capacitor

    • Seetharaman says:

      You can use resistance but the current and the voltage will be in phase hence the consumption will be V X I= 230 X 0.05(for 50mA LED) that is 11.5 watts. but if you use the capacitive reactance for dropping (in a capacitor voltage lags current by 90deg ie VI Cos pi VI X 0 that is zero watts) the dissipation is zero. so the power consumed is led voltage and the current flow through it. say each led is 3.2 volt at 50mA then the power consumed is 3.2 X 0.05 X 24 just 3.84watts a clear saving of 7.6watts.

  • cooool says:

    Sir I am beginner in

  • cooool says:

    Thank you sir for your reply

  • cooool says:

    Sir for 20mAh led what change is required

    • Seetharaman says:

      Hi cool reduce 1uF 400 volt to 0.27uF 400volts (if not available use 0.22uF 400volt can be used resulting in small reduction in LED brightness not noticeable to our eyes)no other modifications are required.

  • vignesh says:

    sir wat s the voltage before bridge resistor

  • A.G.Wimalasena. says:

    Dear Mr.Seetharaman,
    When this circuit is on will it protect from lighting,surge,or high voltage application.

    Thanks

    Wimal

    • Seetharaman says:

      Hi You have to use VDRs (265 volts) after 100 ohms and before 1uF capacitor or atleast Zeners (2nos 39volts zeners connected in series)across the LEDs to protect them.

  • mubarak says:

    sir

    i have a problem for led circuit power calculation. i will make 30 nos of 230v led circuit. i make 3 circuit of this for one light. it take 87mA current.each circuit got 27 mA. i culculate this circuit power. P = VxI
    P =230 x 0.087 P= 20.01W BUT CIRCUIT HAVE WRITE EACH CIRCUIT GET 1.6 TO 2.4 WATTS I WILL ATTACH THAT CIRCUIT
    PLEASE SIR EXPLAIN ABOUT LED CIRCUIT POWER CULCULATIONSuper
    Bright LED Lamp
    This simple 1 watt LED lamp can give light equal to 11 watt CFL. It is directly powered from AC using capacitor power supply. The light from this 30 LED lamp can very well illuminate the room and is suitable for reading purpose also.

    Capacitor powewr supply uses 474 J AC capacitor and standard full wave rectifier comprising diodes D1 through D4.C2 act as the filter capacitor. R1 is the bleeder resistor to discharge capacitor C1 at power off. 30 High bright White LEDs are connected in series with current limiting resistor R2.

    CIRCUIT DIAGRAM:

    High bright Flood light LEDs:

    New versions of low current high bright LEDs are now used to make home lighting. These LED lamps can replace CFLs and Tube lights and consume only 1.5-2.4 watts compared to the 36-40 Watts of CFL or Tube light. These LED lamps can give 50,000 hours light without fail. Luminance range from 10,000 – 18000 MCD and the operating temperature is from -40 to + 95 degree. Current consumption range from 40 mA to 100 mA in various makes. Input voltage may be 2.8 to 3.5 volts.

    • Seetharaman says:

      Hi Mubarak the voltage of a capacitor lags by 90deg the current through it, hence the active power dissipated by the capacitor is zero. only the LED wattage and the power generated by the resistances alone need be taken for calculation. If you use a step down transformer for the circuit you have to take care of all the losses in the transformer like copper loss core loss coupling loss etc. Hence the above is the best circuit as for as the power consumption is concerned.

  • Niranjan says:

    Dear Sir,

    Wat is the voltage and mA rating for the LED’s and wattage rating of 110k (R1) used in the circuit published by you.

  • In this article part nane is given

  • Romy says:

    Sir,
    Now I have straw hat LED 2.8V, 20ma, whats the changes for this…….

  • suri says:

    Dear Seetharaman Sir,
    I got Polyster capacitor 105K 630V, can I use this in place of 1uf 400V.

    • Rolando D. says:

      Hello Mr. Seetharaman,
      if I used 144 pcs.LED white , what will be the value of discharge resistor(R1)atC1 ,the R2 the inrush current preventer, R3 after the bridge diode. Diode rating, filter capacitor C2 or can i used zener here? kindly
      give advised , it will be wattage to 9 watts..

      many thanks,
      Rolando D.

  • hemendra says:

    Dear Mr.Seetharaman,

    I have tried your circuit with 31 led and it was successfully working.Thank you for the post of valuable circuit.If i want to increase led up to 50 and what changes do i have to do?(because 24 led out put not enough for me to use @ home)If i use 50 leds what will be the out put watts of the circuit.

    Tks.

  • Romy says:

    Today My 10uf capacitor burn. Please reply sir.

  • Romy says:

    Sir,
    I got Polyster capacitor 105K 250V, can I use this in place of 1uf 400V. Actually I completed my circuit with this capacitor and it works perfectly but after 2 day 3 LEDs of my circuit is dead. My LEDs are very cheap and low quality because out of 100 LED my 46 LED are already dead when I tested that at my home. So I am in confusion that 3 LED in circuit are dead due to capacitor or because of low quality.

    Regards

    • Seetharaman says:

      Hi Romy it is due to your LEDs mainly as they are not rated for 50mA. if it is 25mA you have to reduce the capacitor value to 0.47uF 400 volt capacitor. 250 volt cannot be used. with 115volt 60Hz it is ok but not with 230volt 50Hz.

      • Nirav Patel says:

        Hi sir,

        My question is that how can we find LED’s Rated mA. as I have the same problem as I am using .47uf 250Volt Capacitor for 10 LED with two Resistor 1M 1/4Watt & 470K 1/2 Watt.

        Regards.

  • Amit says:

    Dear Seetharaman Sir,

    I connected a single 8mm,20mA White LED in series with a 0.22uF capacitor after the rectifier diodes without any resistors as I thought the capacitor is giving 20mA current but within few seconds the LED got burnt out. Kindly tell where I am wrong.Tell me the if anything else is required

  • Amit says:

    Dear Seetharaman Sir,

    I want to make circuit of 12 White LEDs using Capacitor. Please tell the
    value of Resistors. Can I use a 0.22uF capacitor?

    Also Tell me the formula to calculate the resistor values

    Thanks!

  • Romy says:

    Sir,
    I did’nt find 1uf 400V polyester capacitor but I have same value i.e. 1uf 400v Electrolytic capacitor Can I use this in place of C1 in above circuit

    Regards.
    Romy

  • Mihindu says:

    Dear Sir,

    i already make this circuit, it is very bright.
    Now i want to add 80 leds, please help me

    Regards
    Mihindu

  • Hi Mr Seetharaman i would to like to know power consumption for 40 LEDs 3.2volt 20mA. how many watt it consume. tkz.

  • Seetharaman says:

    Hi Anir 2 X 100 ohms is for limiting inrush current to around 1Amp. For voltage drop and the LED current is known. Calculate the dropping resistance value required. Now instead resistance use the reactance of the capacitor. calculate the capacitor by using the formula
    Frequency(f) = 1 / 2π (√R X C) where frequency in Hz, resistance in ohms and capacitance in farades.

  • Anir says:

    how to calculate the value of capacitor (1uF,400v) and the value of resistor (100-ohms) used in the circuit

  • k.k.sabari says:

    hi. . Whts the basic calculation of RC circuit (Resistance & capacitor)
    (to be glow the no f leds)

  • Seetharaman says:

    Hi Kasun infact it should be 0.42uF to give 20mA but the standard value available is 0.39uF, which will be quite safe for the LEDs. With 1uF 2nos in series (0.5uF) the current will be 22mA for the LEDs. with the component tolerance of 20% and the domestic voltage fluctuations the current may shoot to more than 25mA which may kill your bad LEDs. with 3nos 1uF in series the LEDs will get just 15mA which will be quite safe for the LEDs due to the above indicated reasons. May be the brightness will be slightly lower, which you cannot make out.
    Hi Mohmmed 0.47uF 42LEDs, 0.82uF 67LEDs, 1uF 74 LEDs of 3.2volt 20mA

  • Kasun says:

    Dear Mr.Seetharaman,

    Iam connecting 40 LEDs(3.2v@20mA)with above circuit.Please Let me know which is better for following two capacitors?
    1. 0.39uF(400V)
    2. 0.47uF(400V)

    This both are is good or should be better 0.39uF than 0.47uF?
    Also I have 500 pcs pack or 1uF(400V) that’s mistakes buy for this circuit. However how that capacitors use with 40 LEDs(3.2v@20mA ? Which value of capacitor for add as parallel with 1uF(400V)?

    Please reply me soon. Thanks in advance!!!

  • Kasun says:

    @Seetharaman: Thank you very much sir for your Quick reply. However regarding below comment 0.39uF also working fine for 24LEDs(3.2V@20mA) also? Its mean 24 to 40 LEDs(3.2V@20mA)is working fine with 0.39uF?
    Please explain this.
    Thanks in advance!!!

    Mohammed Faiyaz: Thanks lot for your suggestion. When I make fist time this circuit with 24 LEDs(3.2V@20mA), I face same problem & that all LEDs was burned. but After change value of 1uf to 0.39uF, now this circuit working as great.
    Regarding use 1uF- its need 72 LEDs(3.2V@20mA)I think. Please see previous comments.

    Seetharaman
    December 19, 2011 at 4:51 pm
    Hi Malli for 24LEDs(3.2V@20mA)of your specification reduce 1uF to 0.39uF, for 48 LEDs reduce 1uF to 0.57uF (0.47 + 0.1uF) for 72 LEDs use the above circuit no other modifications are required.

  • Hi Mr Seetharaman im waiting for you’re reply i want to know how many 3.2 Volts 20mA LED’s can glow on 0.47uF, 0.82uF, 1uF, Min & Max Qty’s LED’s ? Plz Reply ASAP.

  • Hi Mr Seetharaman im waiting for you’re reply i want to know how many LED’s can glow on 0.47uF, 0.82uF, 1uF, Min & Max Qty’s LED’s ? Plz Reply ASAP.

    KASUN:- I have constructed 27 QTY 3.2v 20mA LED’s with 0.47uF, after 2 days 2 LED’s get damaged and also its getting heat and its too bright, then i have increase from 27 to 39 LED’s now its working fine.

  • Seetharaman says:

    Hi Kasun decrease 1uF 400volt to 0.39uF 400volt no other changes are required

  • Kasun says:

    Dear Mr.Seetharaman,

    Iam connecting 40 LEDs(3.2v@20mA)with above circuit.Please suggest the required changes.

    Thanks in advance!!!

  • Seetharaman says:

    Hi Najimi 4volt is too much for the LED. First check with 3 volts battery how much they are consuming use that figure for calculating the circuit values. they my be 3 volt 20mA LEDs, which will not suit the above circuit. it has to be 3.2 volt 50 to 60mA LEDs. (they are called triple LEDs one encapsulation with 3 LEDs of 20mA each)

  • Surendra Biyani says:

    Hi,
    I need instructions and guidance in replacing 4 volt bulb using 0.8 Amps
    I am keen to have a circuit using a cluster of 5 LEDs of 5mm dia emitting
    total 30 lumens. Using 5 LED reduces emmission of temp.,so no need for a
    heat-sink. The Charging voltage is 6 volts DC, which charges a lead-acid
    rechargeable Battery of 4 volts /10 Ampere-hour.
    The current entering the circuit is approx 4.1 volts DC and the LEDs’ are
    3.2 volts. I have put 10 Ohms resistance in each LED in parralel and they
    burn reasonably well. But the problem is when they are switched on and 6 volts DC flows,thereby reducing the life.Seeking higher life of LED.Please suggest some gadget that will last atleast 30,000 hours in
    the circuit. Please help. My email : surendra.biyani@gmail.com

  • najimi says:

    sir i bought the led,s from electonics shop 8mm they dont know the led volt and wattage any way i mde modification and i connected it as you told, Each led is showing around 4 volts after 1 minuts all led,s blown how can i know the wattage and volt of the led if i remove the filter capasitor main voltage is showing 92 volot

  • Hi Seetharaman, i have constructed this with 0.47 UF and 27 LED’s, 20 MA 5mm. its working fine, but little bit LED’s getting heat up what can i do ? and also i want to know how many LED’s 25 ma can glow on 0.47 minimum and maximum quantity plz reply ASAP.

  • Seetharaman says:

    Hi Ronak yes both the 100 ohms to be reduced to 33ohms.

  • Ronak says:

    Thank you sir.
    Could you please tell me if both the 100 ohm resistors are to be brought down to 33 ohms?

  • Seetharaman says:

    Hi Ronak you have to increase 1uF to 2.5uF 400Volts and reduce 100 ohms to 33 ohms 1 watt. increase 10uF 160 volts to 47uF 160volts.(350volt is preferred if you are likely to disconnect the LEDs, or may get disconnected if they are on a different board)

  • Ronak says:

    Sir if I want to use 24 nos. of 150mA(8mm,0.5 watt) LEDs, then what changes do I need to bring ?

  • Seetharaman says:

    Hi Kasun this circuit can feed only 50 to 60mA maximum to the LEDs. For 1watt LEDs use standard drivers of 350mA which can drive 1watt LEDs 3nos in series.
    Hi Prasad with standard 50-50 LEDs 50 to 60mA will be the requirment. for 100mA 10mm leds you have to add 0.8uF 400 volt n parallel with 1uF 400 volts, Reduce both 100 ohms to 47 ohms 1 watt

  • Kasun says:

    Dear Sir,
    If we use 1W(300mA-350mA) LED with this circuit, How much LEDs use with for this?
    Thanks so much gave this great circuit for us!!!

  • Kalikaprasad Mukherjee says:

    Dear sir, if I use 100 mA white LED shall I have to increase the wattage of the resistor and what will be its value? Thanks

  • Dear Mr.Seetharaman,I want to use high brite white 3.2volt 100mA LED instead of 50mA led.In your circuit you use 50mA led.If I use 100mA led it requires to change the wattage of the resistors.Please let me know the value

  • Pratima says:

    hey seetharaman i hav a few questions about ‘battery charger circuit using scr’.i hav left you mail..plz reply fast my submission date is near.plz

  • Philip Joy says:

    sir my 56 LED- lamp was working fine- but 3days before, it went out- the 10uF capacitor had blown and also one LED was gone- i replaced them- today evening, suddenly the light started flickering- flashing in 3-4 flashes per minute- where could be the problem?

  • Ronak says:

    Sir if I want to use 24 nos. of 150mA(8mm,0.5 watt) LEDs, then what changes do I need to bring?

  • Philip Joy says:

    oh ok thank you- but they r a bit expensive online and is not available locally thats y.

  • Seetharaman says:

    Hi Philip to a minimum of 1 and a maximum of 6 LEDs in series. If you feel the brightness is little less you can increase 3uF to 4uF. No other changes are required. By adding more LED the current will come down little, you will not be in a position to distinguish the brightness change without the help of a Light meter. For higher current LEDs of 300mA and above, I always prefer a driver which is available for a maximum of 3 LEDs in series, which will give you a constant light output and safe also.

  • Philip Joy says:

    Sir is this for 2 LED’s or 4LED’s?

  • Seetharaman says:

    Hi Philip you have to increase 1uF to 3uF (1uF & 2uF in parallel) and reduce both the 100 0hms to 22 ohms with >2 watts rating. no other modifications are required.

  • Philip Joy says:

    Sir what modifications to be made if i’m using 3.2V, 300mA power LED? I intend to make a 2LED and a 4 LED version.

  • Mr S S Datta says:

    Dear Seetharaman
    I just came across your contribution in circuits today.com website
    I have a 23led emergency lamp using a rechargeable battery
    Problem the capacitor and resistor in parallel connected to one mains point 230 v has blown out
    Cold you pl let me know what are their values.
    Early reply requested
    Thanks
    Mr Datta

  • Philip Joy says:

    Oh Sorry my mistake- I used ordinary ones- triple chip ones are not available here

  • Seetharaman says:

    Hi Philip 24LEDs of 3.2 volt 50mA (triple chip type)is better than 9watts CFL. Definitely something wrong. are you using tripple chip or normal. if it is normal then your eattage will be 3.2 X 56 X .02 that will be 3.6 watts.

  • Philip Joy says:

    Oh 9W? But then an 8W cfl is more energy saving right? it definitely gives more light than this one. Please shed some light-

  • Seetharaman says:

    Hi Philip Congrats. it will be 3.2 v X 56 X 0.05= 9 watts approx. After switching off the current through the LED exponentially redueces hence a faint glow will be seen in total darkness for some time.

  • Philip Joy says:

    Hi its working perfectly now and my night hours will have less impact on electric bill- one interesting thing i have noted is that the LED’s glow for a lil while even after turning the lamp off- i made it the 56 led way- how much power would it be consuming? 78*50mA=3.9 watt?

  • Seetharaman says:

    Hi Philip thank your stars the capacitor should have blown, do not energise without load connected. What you have measured is not the correct voltage, measure only after connecting the load (as there is no zener diode to protect the circuit)it will be around 78volts.

  • Philip Joy says:

    I just tried measuring the voltage b/w the output terminals without connecting the LED’s yesterday- it showed 17V dc and the 160uF cap was heating up- is this normal?

  • Seetharaman says:

    Hi Faiazuddin you require 12volt DC only as three lEDs are connected in series with a current limiting resistance. you can use 12 volt rechageable battery with charger.
    Hi Philip you can use 56 LEDs of 3.2 volts 50mA with 1.5uF and with no change in all other components. If you use with 24LEDs all will blow. You can use 2 strings of 35 LEDs in parallel (total of 70LEDs) with 1.5uf.

  • Philip Joy says:

    Hi 1uF poly cap was not available so i got a 1.5uF cap(400 v)- so how many LED’s should i connect with all other components remaining same?

    also in the above ckt, how many parallel LED strings can be connected?

  • Faiyazuddin says:

    Hell Seetharaman i want to do same project with LED Strip is it possible to work,
    an i dont know exat details of this LED strip but its work on 12V DC an i dont know what is the power consumption iam uploading the image link:- http://img20.imageshack.us/img20/1195/ledstrip.jpg

    is it possible to work on AC current like this components plz reply,
    an thanks for earlier reply.

  • Olafimihan says:

    Goodday sir, i want you to send me a schematic diagram using block to describe how a 12v dc power supply may be derived from an ac main source of 240vrms. Please help me out sir

  • Seetharaman says:

    Hi Sankar since we use the Xc of the capacitor, we are concerned with its value and the applied frequency. The voltage choice depends on the applied voltage . here in the above case it is 230VAC. Hence a capacitor of 1uF with an operating voltage of 230volt AC is ideal(unfortunately these capacitors are not readily available in the market) but by calculating peak DC (it is 325Volt)1uF 400Volt (standard voltage range available in the market)can be used successfully.

  • Setharaman says:

    Hi Sankar as we are using Xc of the capacitor only the value of the capacitor and the applied frequency counts not the voltage. voltage depends on how much we apply. here 230 volt AC is used, you can use 1uF 250AC (which are difficult to find in the market)or to take care of peak voltage 1uF 325volt DC. (the standard voltage available is 1uF 400VDC).

  • Sankar says:

    Dear Sir,

    Please confirm the type of capacitor that is to be used – 1uFd/ 400 Volts Dc Poly.capacitor or 400 volts AC capacitor. Using different value capacitors will give different voltages as out put. Am I correct?I hope AC Capacitor works more perfectly than a DC capacitor.

  • seetharaman says:

    Hi Faiyaz the capacitor is 0.1uF 400 volts you have use 5nos in parallel so donot use. Resistances are OK. 0.47uF 250 volt AC capacitor is the right component.Please go ahead constucting the projects you will be sucessful.

  • Faiyaz says:

    Hello Seetharaman, i want to use 24 Led 5mm, as per ur instruction i have to use 0.47uF 400V. but im getting 0.47uF 250V can i use this is it compatible let me know plz reply asap.

    an also iam sending components images links,
    following components i have got is this ok ?. plz check 1uf 400 & 0.47, 250VAC
    1)1uF 400V http://imageshack.us/photo/my-images/213/03052012524.jpg/
    2)0.47 250V http://imageshack.us/photo/my-images/440/03052012525.jpg/
    3)resistors http://imageshack.us/photo/my-images/171/03052012527.jpg/

  • seetharaman says:

    Hi Tajinder use the following link for your requirement
    http://ixapps.ixys.com/DataSheet/LDS8726-Datasheet-_Rev-N1_0.pdf

  • Sir,
    We are looking forward to assemble led tubelights, would need your help to fix the driver for the same, i intend to use between 240 to 300 smd leds type 3528 each having fv – 3-3.3 volts and Iv – 20mA in my tubelights. Can u recommend me some driver design to run them safely and how many should i connect in series and how many in parallel connections. each of the leds have max. driving current 25 mA.
    The design that i am looking forward should run these leds anywhere between 20-25mA constantly.
    Thank you

  • Seetharaman says:

    Hi Kosala This can happen if you have used normal 2 pin high bright LEDs, which are meant for 30mA maximum. Now check each LED by supplying from 2nos pentorch cells in series. If they glow alright the problem may be due to capacitor 1uF has become dry or 10uF short or 1N4007 defective. With 2 pentorch supply if LEDs are not glowing check each LED if all of them are damaged check a spare LED with 2 cells and if the glow is ok check the current say if it is 30mA then reduce the capacitor 1uF to 0.47uF 400 volts replace all the LEDs and use.

  • kosala says:

    dear sir…please help me…I made this circuit and after a few days bulbs don’t work please help me…I’m really happy with Ur circuits..so please respond me soon..

  • jeev says:

    dear sir, how much value of resistors should be provided in the circuit for example 220v circuit drops down to 24v how much value of resistor should be provided and how much the wattage is there any specific calculation i dont know the ampere of the circuit

  • jitender sharma says:

    Dear sir
    can u send me 36w led drivar circuit diagram input voltage Ac-220 output and i need output DC 42v.

    thanks and regards
    jitender sharma

  • kosala says:

    I made this and after a few days bulbs dont work please help me…

  • Ian says:

    Hi, If I wanted to use 1.5-1.6V 60mA LEDs I assume I could just double the number up to 48 instead of 24 3V 50ma LEDs to make up the change in voltage between the two types of LED?

    Since 48 is a lot of LEDs to blow up in one go if I get it wrong what changes would I need to make if I wanted to use just 24 of the 1.5-16V 60mA LEDs?

    Thanks

  • PK says:

    Hi sir,
    For brighter Light I used 55, 3.2-3.6v,20ma cool white led with .47+0.1 µF (0.57 µF). But these are warm @55 °C. These are also not bright enough for small room.
    Thanks,

  • Jeh says:

    Hi Seetharaman, I have successfully assembled the project and it is working. Thank you for that. There is one thing I observe though which is the LEDs are not bright enough though they are not getting hot. Can you give me some points to check so that at least I could make some adjustments to make it brighter? I wanted it to be as my lamp inside my room. Thank you.

  • PK says:

    Thanks for reply Sir.

  • Seetharaman says:

    Hi PK standard SMPS for 3 X 1watt LEDs are available the size of the PC is just 10mm/10mm. you can use them they are very in expensive reliable chinese make.

  • PK says:

    Dear Sir,
    Thanks for reply. It seems ok now.

    Another question – I got 1 watt LED (3.4 V 300 mA), can I drive one or more of these with 230 V Ac? How?

  • Seetharaman says:

    Hi PK it is OK it can be around 50deg, feel the temperature after using it for 6 to 8hrs if it is warm (check the temp with IR thermometer after switching off) if it is within 50deg it quite OK you can go ahead.

  • PK says:

    Previously I used 0.33µf+0.1µf but found around same amount of temp so reduced to 0.33µf, but still same temp?

  • PK says:

    Dear Sir,

    I built 3.2-3.6v,20ma 24 cool white led light using 0.33 uf/400v cap, other components as it is.
    Using IR temp gun I found around 52 C temperature in LED base, is it normal or I should reduce Cap value ? Other components are normal.

  • Jeh says:

    Thanks Seetharaman for the reply. More power!

  • PK says:

    Dear Readers,
    I found this small and very useful calculator,I thought I should share the link here, it might be useful to you.
    http://www.electronics2000.co.uk/download.php?source=ea_calc_ad#assistant

  • PK says:

    Dear Sir,
    Thanks for this very useful circuit and satisfying each and every one’s query patiently.
    I want to make warm white LED lamps to replace CFL’s in my house, however I could not find resources in India. Could you give me links or shop names where can I find one. Is there anyone having such difficulty?

  • Bharath says:

    Thanks Seetharaman! Will update the status soon :) ..

  • Seetharaman says:

    Hi Jeh you can use 600volt capacitor, it may be slightly bigger in size than 400volt one. you are always comfortable with higher voltage capacitors, provided the space is not at premium.

  • Jeh says:

    Seetharaman, I was able to order capacitors for C1 in Singapore however it is rated 600volts instead of 400volts, will there be any bad effect?

  • Seetharaman says:

    Hi Jay it is only to discharge the capacitor during switch off. It can be the same value.
    Hi Bharath add 0.68uF 400 volt capacitor in parallel with 1uF no other modifications are required.
    Hi Asim is your model working, if not some mistakes may be there. If working and getting warmed up it is ok the required rating is only 1/4 watt. Any mistake in the circuit it should burn to protect other expensive components.

  • deepak says:

    Hello sir,
    I want to make the DC(12V) to AC(230V) “pure sine wave inverter circuit”. Please if you have any circuit or ideas please mail me or post here. I want the circuit design for minimum 100W power output with 230V pure sine wave.
    Please reply me i am waiting for your reply!
    -Deepak
    mail-deepkajale@gmail.com

  • Bharath says:

    Dear Sir,
    I have calculated the value for the first capacitor in your circuit (1muF)- however, how do you calculate the resistance values, bridge and the value of the second capacitor?

    Looking forward to your response. Thanks!

  • Bharath says:

    Hello Seetharam,
    If I were to use 60 LEDs of 50mA, what are the modifications required?

    Thanks!

  • asim says:

    100 ohme resistor hot

  • Jeh says:

    Hello Seetharaman, Thank you and I appreciate your reply. May I also know if I can use the same value of resistor (220K 1/4w) if I wanted to change the value of the capacitors to be used for LED’s more than 24 nos, say 50 LEDs? Thanks again

  • Seetharaman says:

    Hi Jeh You can try by connecting 2.2uF 600 volt capacitors in series back to back (+ve of both capacitors connected together and both capacitors negative terminals used in the circuit make it 1.1uF non polar)with 220K 1/4 watts resistances connected in parallel with each one of them.
    Hi Nagaraj you can submit your comment on the leave a reply coloun with your name and email address which will not be published. you can send your well tried circuits with the prototype’s photgraphs and a detailed write up to Mr. John of circuitstoday through his email id john@circuitstoday.com
    Hi Arun Kumar you can use the same above circuit with 60 LEDs of 20mA by repacing 1uF 400volt with 0.68uF (can be 2nos 0.33 in parallel or one 0.47 and 0.22uF in parallel)400volts and 10uF160volts with 10uF 400volts. For 120LEDs use 2 sets of 60LEDs in parallel by using 1uf and 0.33uF in parallel in place of 1uF400volts in the above circuit, no other change is required.

  • Vincent says:

    Sir. How Many diodes can this handle? Is there A minimum? I’m planning to use 10 diodes. Thanks!

  • arun kumar says:

    Dear Mr Seetharaman,

    I am an amateur and would like to replace all incandescent bulbs in my home with suitable LED lights.I plan to use 60 and 120pcs of LED’s used in 60 pcs in series and also in 60 x2 configuration (60 in series string and two parallel strings)Each led has Vf 3.2V, If 20mA ,reverse voltage 5V.Can you pls suggest a reliable circuit with values for the resistors and capacitors to be used .

  • J S Nagaraj says:

    how to comment and upload circuits?

  • Jeh says:

    Hello Seetharaman, I have been scouting for 1uF/400v capacitor here in my country but it seems that the only maximum available value we have is 0.1uF. Most capacitor with voltage capacity of up to 600v are electrolytic type capacitor. Could you advice me if it is possible for me to use such polarized capacitor and how to connect it. I am really exicited to assemble this project.
    Thank you

  • UDAYAKUMAR.S says:

    Dear Sir

    I tried the 24 LED circuit, it is very good and useful in small rooms. So many circuits i examined. I need good brightness to use in my house to avoid CFL. I used 8mm white LEDs. So I request you to send such a circuit and help me. Thank you. Udayan

  • seetharaman says:

    Hi Yadi it cannot be predicted. you please feel the LEDs for temperature after a glow of minimum 3hrs. if they are warm better to reduce the current else their life will be reduced drastically. if they are cool running it is safe you can use it with 1uF itself.

  • yadi says:

    hi sir,
    thank you for your answer. 0,33uF cannot find in local market. i am already assembled 40nos dip 5mm strawhat led using 1uF 400V polyester capasitor, and the led glow very bright. i has been tried in 3 days, and the led is just fine. how long the time the led can be glow using dip 5mm strawhat with 1uF capasitor?

  • Seetharaman says:

    Hi Yadi the maximum value is 20mA at 3 to 3.2 volts.If you use them in the above circuit you have to reduce 1uF 400 volt to 0.33uF 400volt polyester capacitor. no other change is required.

  • saifullah says:

    if i want 2 increase the number of led what changes should i bring

  • yadi says:

    hi sir,
    what is maximum forward current value for dip 5mm strawhat superbright? because i use this for above circuit, but the led is not broken.

  • pavan says:

    hi sir, very nice circuit,but cap current capacity (100 ma peak ) is greater than and led max currentas u said 50 ma peak ). then how can leds withstand such a huge current.

  • Stanley M says:

    Hi Rasitha,
    Wattage consumed by 24 LEDs @ 50 mA is 3.85 Watts. This is assuming that the voltage drop across each LED is 3v.
    If drop across each LED is 3.2v, then wattage is 4.09 watts.
    Send me your email address and I will mail you a calculator that I have made for finding Cx, Wattage and current flow thru LEDs.
    How is the quality of the output Light. Is it bright enough to light a decent room. I am very much waiting to assemble this ckt.
    What is the cost of 50mA LED in your local market?

  • murali says:

    Seetharaman sir, May the Year 2012 bring for you happiness, success and filled with Peace, Hope & togetherness of your Family & Friends…Wishing you a HAPPY NEW YEAR.

  • rasitha says:

    sir,
    i assembled the circuit .. It is nice….what about the wattage of this and 50 LED circuit….

  • Stanley M says:

    Hi Seetharaman,
    What is the price of a High Bright White 3v 50mA LED in your local market?

  • Stanley M says:

    Hi Seetharaman,
    These High Bright White LEDs (3v @50mA) are they available in 2 pin or 4 pin or both type packaging.
    If 4 pin packaging, how to wire them?

  • seetharaman says:

    Hi Stanley you have to use both voltage and current peak value to calculate with filter capacitor, or both in RMS value. o.4 is not a standard value you can use 0.39uF which is around 2.5% less but will suit as the current change will hardly be noticed.

  • Hari says:

    Hi seetharaman
    What are those resistors for ? Are the series resistors used for surge current protection ? What are the parallel resistors for ?

  • Stanley M says:

    Hi Seetharaman,
    Are 0.4Uf standard cap available?
    What combination to achieve 0.4Uf?

  • Stanley M says:

    Hi Seetharaman,
    In fact in many calculations and in your responses to Japanjot, Murali and Rahul, below, you have used 230 volts rms to calculate voltage to be dropped.

  • Stanley M says:

    Hi Seetharaman,
    With regards to your response, I am confused. In all previous comments to Cx calculations, you have said to use rms value of dropping voltage. Now you have responded to me to use peak value. Pls clarify

  • Stanley M says:

    Hi Seetharaman,
    Are 0.4Uf standard cap available?
    What combination to achieve 4Uf?

  • Seetharaman says:

    Hi Rasitha increase 1uF to 1.2uF no other change.

    Hi Stanley it should be 0.4Uf for 15nos 25mA LEDs,
    for 300LEDs of 3volt @ 50mA it should be 9uF. calculate for peak voltage and current as AC is converted to DC. above 108LEDs no capacitor required, better to prvide a 250volt VDR as protection against surges.

  • Stanley M says:

    Sir,
    If I use 100 LEDs of 3volts 50mA rating, then total voltage a/c LEDs will be 300v (100 x3). But my mains is only 230v @50Hz. So logically no Cx required because no voltage drop required. Is my logic ok. If Cx required then how to calculate in this case.

  • Stanley M says:

    Hi Seetharaman, I have connected 15 LEDs (3volts 25mA) in series using above ckt. Now using formula, I have come to value of Cx as follows. Please let me know if my calculations are right. Also what is the standard nearby value of Cx available.

    Total voltage a/c LEDs is 45v @ 25mA (3 x 15). So votage drop required is 185v @25mA (230-45). So R is 7.4k ohms (185/0.025). So Cx is 0.43mF. So what is standard nearby value of Cx

    Secondly, If I use 21mA for LEDs Cx comes to 0.36mF. So can I use 0.33mF Cap?

  • rasitha says:

    sir,
    …….how i can cnnct 50 LED s……to this circuit…what will be changed……?..

  • seetharaman says:

    Hi Malli check after running for 15minutes whether LEDs are getting heated up. if not no problem. if they are getting heated up reduce the capacitor value to next available lower value. Driving the LEDs with higher current will reduce their life.

  • malli says:

    Hello sir here the available capacitor are .22 .33uf .47uf .68uf, I tried with .47uf for 24 led and .68uf for 48led its working fine and bright. can i use like this or i have to change. all leds are 3.2v 20ma. if i have to change what should i do pls help me sir

  • Seetharaman says:

    Hi Malli for 24LEDs of your specification reduce 1uF to 0.39uF, for 48 LEDs reduce 1uF to 0.57uF (0.47 + 0.1uF) for 72 LEDs use the above circuit no other modifications are required.
    Hi Nishanth you cannot mix up LEDs. same type alone can be used in series. To use 50nos RED LEDs in series use the same circuit reduce 1uF to 0.33uF no other component requires any change.

  • Nisanth says:

    hello sir,

    please explain how to connect 50no’s of LED in AC mains

  • Nisanth says:

    hello sir,

    how can I use five bright LED’s forty five red LED’s in the circuit in series.What changes needed to make in the circuit

  • malli says:

    sorry sir its 3.2 3.4v 20ma led. not 25ma. please help me

  • malli says:

    sir i have 3.2-3.4v, 25ma led iam planing to do 3 types of led, 24nos, 48nos, 72nos please help me and let me know what are d changes i have to make in this circuit
    malli

  • Jeh says:

    Thanks Seetharaman for the unselfish reply/information. May I again ask you a favor if you could publish a transformerless power supply circuit that is connected from the main (240v) and gives an output of 9v dc. This is to be used for IC operated projects like LED Chaser etc.

    More power!
    Jeh

  • Seetharaman says:

    Hi Jeh you can use 2 capacitors in series, ensure that you use 220k resistance in parallel with each capacitor. (capacitor voltage value will get doubled but capacitor value will get halved if you use them in series).

  • Jeh says:

    Hello Seetharaman, We dont have 400volts range. We only have 250volts. Though some electrical appliance use 2000volts. Can I use the 250volts capacity?
    Thanks

  • Seetharaman says:

    Hi Jeh what is the maximum value available in your market in 400volts range. if 0.47uF(470nF) use two in parallel.

  • Jeh says:

    Hello Seetharaman, Thanks for the reply. I intend to assemble the project that I have bought all the parts except for the polyester capacitor (1mf/400v) which is not available locally. Could you advice me if what could I use as a substitute?
    Thanks and more power

  • nagaraj says:

    what about the bridge rectifier diode number(in4007 ah?)

  • seetharaman says:

    Hi Hari in this circuit current and surge limiting are taken care by 100ohms before and the one after bridge rectifier plus the filter capacitor 10uF before LED circuit
    Hi Jeh the above circuit is the correct one.
    Hi Anish you are correct normal LEDs can handle but they get heated up soon . you kindly checkup the temperature raise of LEDs after about a minute of glowing (by using heat sensitive part of your body-may be back portion of palm or face) if it is quite warm, the LED current has to be reduced or you have to use thick large PCB to dissipate the temperature. if the raise in temperature in not taken care the LEDs will fail fast.

  • ANISH says:

    Hai seetharaman sir,
    My attempt to find whether the LED’s I have are super bright or not:
    I do not have a constant current source. So, i used a 5v regulator and 200 ohms resistors which gave around 24mA. Then the voltage drop was around 3.0 volts. When I replaced 200R with 100R, the current supplied was around 46mA and the voltage drop across LED is around 3.15V. How can I conclude? BTW, normal LED’s wont stand more than 25mA i think… Am i correct?

  • Jeh says:

    Hello Seetharaman, I was looking/surfing for a circuit for LED and found this site. I read the chain of messages and have read about the circuit diagram which is incorrect. You said that you have corrected on your comment dated 26 June 2010 of which I did not see. May I know if the diagram above is now the edited or corrected one?
    Thanks and regards

  • hari says:

    Hi Seetharaman,
    Thank you for the help. One more doubt. There are strong recommendations to use LEDs only with a current limiting resistance(since a small change in V can make greater change in I without a resister in series and harmful for LEDs.) I guess 100E used after bridge to limit surge also acts as a current limiting one. Or do we use one more suitable resistance for current limiting ?

    I found some useful information regarding LEDs with FAQ and some wizards to calculate circuit config. at
    http://led.linear1.org/led.wiz may be useful for many reading this post.

  • seetharaman says:

    Hi Hari with 3.2 volt 25mA LEDs it will be 61 volt 25mA. you require only 0.39uF at the most you ca use 0.47uF. with 1uF it will draw >50mA which may damage your LEDs. If you wand Zener protection use 32volt 1watt zener Diodes in series and in reverse bias condition in parallel with 19uF 160 volts against surge (not really required)

  • Hari says:

    Hi Seetharaman

    Thanks for your advice. Now I have rewired 19 LEDs in Series, but total voltage is around 60V for 19LEDs(using 1Mf/400V). I guess it is drawing more current, since LEDs are VERY bright.
    I invite your attention to your response to Mr. Murali dated October 5, 2010 as…
    “Hi Murali for 19 LEDs reduce capacitor to 0.82uF, a standard value or use a 15volt in series with th LED loop.”

    You didn’t mention the 15V component, I guess it is a zener reverse biased ? Please clarify.
    I hope I can use a 0.33Mf and 0.47Mf in parallel instead of 0.82Mf if available. Here I get only 1MF and 0.47MF/400V capacitors in the local stores and no other value is currently available.

  • seetharaman says:

    Hi Babla each series requires say 25mA current you require 75mA current. 0.22uF 400volt cannot give you the required current raise the capacitor value of 2uF instead of 1uF(connect one more 1uF 400v in the above circuit. now you are getting only less than 5mA current in each loop.

  • Hi i connect the 3 cerise of LED each cerise are 50 LED, i connect IN4007 Diode in Bridge & .22uf/400Volt paralal in 110 K Resistance, each cerise 100 Ohm Resistance But do not Glow Bright,Pl. Help me The Circuit & solb the problem

  • seetharaman says:

    Hi hari for 19 LEDs in parallel it will be 3volts @ 380mA this calls for a 5uF capacitor in place of 1uF 400volts. 100 ohms should be reduced to 33 ohms 10watts. The 10uF should be raised to 100uF400 volts. You have to use 12volts 10 watt zener diode before 7805. no space and not worth the trouble. buy a 3volt 500mA step down transformer and fit it in the space occupied by the battery. feed the transformer output to the rectifier circuit already present. no need for any other modifications. will be most reliable.

  • hari says:

    Hi Seetharaman,
    I have a chinese make LED lamp with 19LED and a 4V battery earlier. Now the battery failed and I wish to convert it to a mains operated lamp. I have modified it with your circuit with an additional 7805 and 47E at the output to get around 3.0V since LEDs are already soldered in parallel. But the input of 7805 is around 32V. what changes should be made to your circuit to get the output voltage around 10-12V so that 7805 will drive safely LEDs in parallel. The LED is small bright white type and works within 2.6-3.0V and 20ma range.
    thank you.

  • V.MANI says:

    Cheap and best. Thank you very much Sir.

  • Seetharaman says:

    Hi Prabhat you ca use 100LEDs of 3volt 25mA standard white LEDs in the above circuit with just one change of replacing 1uF with 4.4uF (2nos 225k 400 volts in parallel)

  • Prabath says:

    cant we use this circuit for 100 LEDs?

  • seetharaman says:

    Hi Asankap it is better to use 400volts if LED chan is likely to have any dry joint or to test power supply portion without LEDs. i prefer 10uF 400volts as filter capacitor

  • AsankaP says:

    Dear Seetharaman,

    Thanks for your reply
    i meant the capacitor after the bridge(electrolytic capacitor).most of the manufactures use 4.7uf 400v cap.i use 80leds(40 in series) and 108leds(54 in series).is 250v capacitor enough or 400v one better?

    Thank you

  • Seetharaman says:

    Hi Asankap it should be 0.47uF 400 volts not 4.7uF.
    Hi Manoj for 9LEDs use o.47uF 400volts inplace of 1uF 400volts no other change is required.

  • MANOJ V J says:

    Thank u Seetharaman Sir for a wonderful circuit. Your circuit is excellent and working perfectly. What are the changes made to reduce the LEDs to 9 nos? Hope you will reply soon.

    Regards
    MANOJ VJ

    Read more: http://www.circuitstoday.com/mains-operated-led-circuit#ixzz1XvawVZ92
    Under Creative Commons License: Attribution

  • AsankaP says:

    Dear Seetharaman,

    Thanks for your reply.is 4.7uf 250v electrolytic capacitor enough for 80leds(40 in series)?.is 400v better?

    Thank you

  • Seetharaman says:

    Hi Asankap for 3.2 volt 20mA LEDs you have to use 0.47uF instead of 1uF. these resistances are for surge current limitting, hence need not be changed. you can use any non capacitor rated for atleast 400volts. 1N4007 you can use PHILIPS ITT EC etc.

  • AsankaP says:

    Hi seetharaman,

    Just a one question.i am using 5mm 3.2v 20ma bright white leds(i drive them at 16ma to get maximum efficiency).What is the minimum safe resistor values for before and after the bridge rectifier(100 ohms resisters)?

    Thank you

  • AsankaP says:

    Hi seetharaman

    thanks for publishing such a valuable circuit.i have few questions regarding this circuit.i had a problem with 1N4007 MIC make and electrolytic capacitor.what are the best brands to use in these energy saving lamps?are nichicon and rubycon good?any specific brand for 1n4007?

    there are different sizes and type of Metallized Polyester Film Capacitors.(ex:-cbb21,CL21).so,what is the best type and brand for better life

    Thank you

  • seetharaman says:

    Hi Deepak for red LED maximum is 2volts at 35mA better not to drive at the limits may shorten its life.

  • deepak says:

    Hello sir, thank you for reply!
    you have given the rating for 5mm Red LED as 1.7V at 20mA
    i want to know that whether it is same for high bright Red LEDs which has appearance like white LEDs when OFF and emits high bright Red light when ON. plz reply!

  • pavan says:

    i want 2 channelor 3or,4 channel led power supply,circuit diagram ,,,,,,,,,,plz sirrrrrrrrr,

  • seetharaman says:

    Hi Deepak 5 mmRed LEDs will be rated for 1.7 volt at 20mA. for 50 LEDs it will be 85 volts. Reduce 1uF 400 volts to 0.37uF 400volts (0.22 in parallel with 0.15uF, 0.33uF 400volts can also be used) no other change is required.

  • deepak says:

    hello sir,
    yes sir i want to connect only 50 nos. of red 5mm LEDs (which has clear glass like outer appearance),so please tell mi what changes should be done in above circuit & component values to make single string of 50 red LEDs. Sorry sir, but i don’t know the current and voltage rating of that red LED so kindly request you that suggest me changes.

  • seetharaman says:

    Hi Deepak you can connect only one colour per string, as the currents are different for different colour LEDs.

  • deepak says:

    hi sir,
    thank u for your reply! Sir please tell mi what changes should be done in above circuit & component values to make single string of 5mm 50nos.of white-to-red LEDs. olz give detail of all changed component & their values.
    plz reply!

  • seetharaman says:

    Hi Deepak you cannot mix up LEDs in serial string as their current ratings are different. you can make 5 different colour individual 5 strings and place the LEDs alternately.
    Hi Anish feed 25mA from a constant current source, check for the visual brightness and measure the drop across the LED if it is 3.2 or greater then the LED is normal one. If the drop is just around 2.9volt. increase the current to 50mA, the drop across the LED is between 3.2 and 3.4volt visual brightness level will indicate it is hi bright LED. if you have lux meter feed 50mA to the LED keep the LUX meter at 1 meter distance it should indicate between 180 and 210LUX. if so it is high bright LED.

    • AM Choudhary says:

      Hi seetharaman,
      I am an old(66yrs) electronic hobbyist need your help. On a 8mm white LED packet written fd-3.2 to 3.6volts, wattage-0.25w. What will be the operating current range of the LED’s. Kindly reply soon.
      Regards
      am choudhary

  • MANOJ V J says:

    Thanks Sir. Your circuit is excellent and working perfectly. What are the changes made to reduce the LEDs to 9 nos? Hope you will reply soon.

    “RAMZAN GREETINGS”

    Regards
    MANOJ VJ

  • Anish says:

    Hi Mr.Seetharaman, please do provide a table or something similar so that we can calculate particular capacitance and resistance needed for particular no.of.leds.

    BTW i have a bunch of 100 white LEDs So, how do i know whether it is super bright or ordinary LED and how can i estimate its current rating…

    Regards

  • deepak says:

    hello sir,
    i want to make mains operated lighting for deepawali using led. i want to make —
    1)50nos. 5mm white-to-red series led string light
    2)50nos. 5mm white-to-blue series led string light
    3)50nos. 5mm white-to-green series led string light
    so i request you that please tell me all the changes needed to make the all 3 cases i mentioned above. i don’t know the rating of these red, blue & green led’s. therefore i request you that please tell me suitable changes.
    waiting for your reply!

  • seetharaman says:

    Hi Murali increase 1uF to 5uF and reduce both 100 ohms to 33ohms 5watts, increase 10uF 160 volts to 47uF 160 volts no other changes are required

  • murali says:

    dear sir i want to connect 3 high power led of 3.2v of 350ma pls tell me what r d changes is requir in this circuit

  • seetharaman says:

    Hi Rohit 56 nos LED 56 X 3.2 is 179.2 volt hence you have to use 250volts capacitor before 160volt is getting blown up.
    Hi Capsun In the above circuit you can use 250volts are higher voltage capacitor
    For 45 LEDs of 3.2 volt @ 20mA use 0.47uF instead of 1uF. no other change is required.

  • capsun says:

    Iam connecting 45 LEds (3.2v @20mA) .Please suggest the required changes .Thanks in advance

  • capsun says:

    Dear Sir I could only find 10 micro farad 250 vols in my place . Can i use this 10 microfarad/250 volts capacitor .Waiting for reply

  • Rohit says:

    Hello Seetharaman,

    I made this circuit, with the following changes
    -56 nos white led used 3.2v 25mA
    -0.47Uf 400v against 1Uf PPC.
    -All other components remained the same, the LED’s light up etc., Is this circuit okay, I figure that the 10Uf 160v will not last long, cause I find it getting warm.

    Kindly advise.

  • CHETAN M.P says:

    Thank you sir.

  • M.P CHETAN says:

    Thanks Sir.

  • seetharaman says:

    Hi Chetan you can use 10uF 400volt.

  • CHETAN M.P says:

    Sir, in my circuit the 160 volt 10 uF capacitor has bulged on the top, so can I use 400 volt 10uF capacitor I have found that capacitor in the electronic choke of tube light.. can I use that capacitor.

  • seetharaman says:

    Hi Yatin is that 72 super white LEDs of 20mA each. you require the same circuit no change is required.

  • Yatin says:

    I want 20 mA output.

  • Yatin says:

    I want to know which capacitor and register work for 72 led light.

  • seetharaman says:

    Hi Rohit use the standard formula. f = 1 / (2 pi R C) you will know the reactance for a capacitor you know the number of LEDs its current calculate it resistance you will know what is dropping resistance required. calculate C from the above formula.

  • rohit says:

    Hello Seetharaman,

    A basic question,In all Mains operated circuit, the voltage is reduced by capacitance reduction, Hence is there a table some where, where
    Example- a 22uf polyester capacitor would provide about 20mA of output current is displayed to make things easier.

    Thanks for all your help

    regards

  • murali says:

    thanks sir

  • seetharaman says:

    Hi Murali change 1uF to 1.5uF. change both 100 ohms to 47 ohms 2 watt. up to 24 LEDs you may not see much change in illumination

  • murali says:

    Dear sir
    i want to make one 10leds and another 16 leds of 8mm, 0.5 watts 100ma leds what are the changes is requir, please help me.

  • murali says:

    Dear sir
    i want to make one 10leds and another 16 leds of 8mm, 0.5 watts 100ma leds what are the changes is requir, please help me.

  • seetharaman says:

    Hi Kumar Blue is 1uF 400volt polyester / poly-carbonate and orange is 10uF 160volts electrolytic. it is available in Bangalore and Chennai.
    Hi Mudassar check your bridge rectifier polarity and check the 1uF it should be non electrolytic check the polarity of 10uF 160volts. If all are OK your bridge rectifier diode may be faulty or connected wrongly.

  • Kumar says:

    Hi, Sir what type of capacitor need to be used in above mentioned circuit diagram (10uF 160V) its ploy or some other type. If its 10uF 160V Ploy in above mentioned 3 pictures in 2nd picture what is that blue capacitor used and whether its available in India (Bangalore).

  • Mudassar says:

    HI sir i assembled this circuit but voltage across bridge diode is 5.3 and voltage across 10uf capacitor is zero,means no voltage, i am using 1uf/250v capacitor, please suggest me the solution, waiting for reply

  • seetharaman says:

    Hi Kumar if you keep the LED circuit open and switch on, a peak DC of 325 volt will appear across the capacitor and blow it. use 400 volt if you are not confident of your wiring. if the circuit is fully connected without any mistakes then LEDs will glow and capacitor will work without blowing, as the voltage developed across the LEDs are just 72 to 80 volts only.

  • Kumar says:

    Hi, 10uF 160V Capacitor got burned why is this problem happening already 3 capacitor got brunt.
    Kindly help wait for your reply.

  • Saifur says:

    Thanks dear

  • seetharaman says:

    Hi Saifur the protective resistances have got burnt(120 ohms). This indicates over current drawn by the circuit. This is due to the capacitor 474K. the voltage rating of the capacitor may be low. try to get 400 volt capacitor and use. the 120 ohms 1/2 watt is more than sufficient. with 474K capacitor the current will be 25ma. 25ma through 120 ohms will be hardly 100milli watts.

  • Saifur says:

    Dear please check those photos, you may get a clearer view

  • Saifur says:

    “what is the current consumption at 3.2volt” I cannot get your question

    “What about 10uF 160volt and 1N4007 are they healthy?”

    10uF 160volt is burned, and 1N4007 are looking normal, but I don’t know, I give those pictures for your advice

    _______________
    June 26, 2011 at 8:32 am
    You Said:
    Hi Saifur These diodes are rated for 3.2 volt @ 20mA. reduce the capacitor from 1uf to 0.47uF. no other modification is required.

    ________________
    I check Led’s packet, & found that they are 3.2 volt, But I cant remember what mA are written in those LED’s packet

    ____________
    I will make this ckt again, But afraid of burned again

  • seetharaman says:

    Hi Saifur what is the current consumption at 3.2volt. What about 10uF 160volt and 1N4007 are they healthy?

  • Saifur says:

    I check LED specification, It is 3.2 volt LED

  • Saifur says:

    Please give me some suggestion, so that when I make this project again , then it will not burned.

  • Saifur says:

    Dear, today it is not on at all, then I check it, and found it burned, What is you thinking about it? I give some pictures of it, Burned pic, A set of parts,

    http://imageshack.us/photo/my-images/220/dsc00004ww.jpg/
    Normal View

    http://imageshack.us/photo/my-images/96/dsc00005pf.jpg/
    Burned

    http://imageshack.us/photo/my-images/14/dsc00006sn.jpg/
    Burned

    http://imageshack.us/photo/my-images/32/dsc00007rh.jpg/
    Closed Vied

    http://imageshack.us/photo/my-images/17/dsc00013zq.jpg/
    Another set of parts,

    http://imageshack.us/photo/my-images/811/dsc00015fn.jpg/
    Burned View again

    I will make it again, want your advice, that It will not burned again, Waiting for your advice, You may guess something after viewing these pictures

    I was happy to make such light by my hand which will consume less current.

    Dear I appreciate your effort of helping us

  • seetharaman says:

    Hi Saifur either your 1N4007 are defective or the LED specifications are different. the same is working in my house for last more than a year without and deterioration. in India we found that to be due to defective 1N4007 replacing them with reputed make,made it ok, no LED has failed. you can also remove LEDs feed 3.2 volts and check for the operation of each one if they are good the problem is 1N4007 only.

  • Saifur says:

    dear, I made it with your support, & at first It gives nice light, but continue running after 2 hr, It goes totally dim ,

    when I switched off the light, then it stops slowly,
    What is the problem do you think?
    waiting for your support. Now I am frustrated.

    these are few pictures of that project
    http://imageshack.us/photo/my-images/641/image0011e.jpg/
    http://imageshack.us/photo/my-images/155/image0012g.jpg/
    http://imageshack.us/photo/my-images/535/image0017vs.jpg/
    http://imageshack.us/photo/my-images/84/image0018j.jpg/

  • Saifur says:

    thanks dear for your feedback,

  • seetharaman says:

    Hi Saifur the photos are out of focus, anyway 474 means 470000 that is 470KPF or 0.47uF. if it is rated for 400 volts you can use it.

  • Saifur says:

    Dear seetharaman, I am facing some problem,
    as ur suggestion, I buy this capacitor, (seller give me this) check this link . It is correct capacitor? I am confused. you said 1uf to 0.47uF 400volt. But seller give me 1H 474K.

    Please check this link to view pic of this capacitor. It is correct one?
    http://img715.imageshack.us/img715/3948/capqc.jpg

  • seetharaman says:

    Hi Saifur These diodes are rated for 3.2 volt @ 20mA. reduce the capacitor from 1uf to 0.47uF. no other modification is required.

  • Saifur says:

    Dear Seetharaman
    If I use normal 2 pin white LED, is there any problem arise? I am afraid that I will not find that 4 pin bright white LED in my Bangladeshi market. Though I am new, forgive my this type of question

    Please suggest.

    ** Please delete my previous two question please

  • Saifur says:

    ** 2 pin white LED

  • Saifur says:

    Dear Seetharaman
    If I use normal 2 pic white LED, is there any problem arise? I am afraid that I will not find that 4 pin bright white LED in my Bangladeshi market. Thought I m news, forgive my this type of question

    Please suggest.

  • seetharaman says:

    Hi Capsun it is due to surge voltage and current.
    to avoid this zeners and filter capacitors are used. Still if it is happening the LEDs may not be of the rated capacity. Any standard reputed retailer will be in a position to help you.

  • capsun says:

    Pls tell me which company capacitora,diodes are best.i found some of the LEDs are burning after swiching it on and off several times.May i know the reason for this.

  • seetharaman says:

    Hi Capsun Replace the polyester capacitor with a good quality 400volt capacitor.

  • capsun says:

    Dear SIr Iam using PCB ,The problem is the brightness is not uniform they are becoming dim for a while and again they become bright.The poly cap becoming very hot.What changes i have to make .Waiting for reply

  • seetharaman says:

    Hi Capsun 16 LEDs of 3.2 volt is 51.2 volt and each LED dissipates 3.2 X 0.13 = 400milli watts. you have to use proper heat sink PCBs for them. if the generated heat is not properly dissipated they will fail.

  • capsun says:

    Dear Sir they are also becoming dull for few minutes and again become bright .The brightness is not constant.Pls tell me whats wrong in my circuit .Waiting for reply

  • capsun says:

    Dear Sir I have connected 16 LEds (3.2v @130mA) in series .I Increased 1 mfd to 2 mfd, added 33v 1 watt zener 2 in series and parallel to filter also changed 100 ohms to 47 ohms but the LEDs are burning out after few hours.Zener diodes also become fail.What changes i have to make . pls tell me . Waiting for reply

  • Seetharaman says:

    Hi Saifur the above circuit is the corrected one after June 26th the mistake was corrected. yes they are 4 Pin Hi Bright white LEDs 3volt at 50mA.

  • Saifur says:

    http://images.blog-u.net/wp-content/uploads/2010/09/Diodes-bridge-Rectifier.jpg
    see this picture.. I cant recognize problem in that & your b rectifier, Please clarify dear as I m new.

    Is these white LED’s are 4 pin?

    as I am new, so I arise this type of question. Waiting for your asnwer

  • Saifur says:

    Dear Seetharaman
    I am new in electronics, but I can follow the circuit. But in some comments (June 26, 2010 at 2:27 am) you said there is some problem in this ckt, & some diagram may rotate 90 degree. Do you please clearly and corrcet the diagram pls so that I can directly follow the diagram

  • CHETAN says:

    Sir, I added extra 12 LED’s that is total of 36 LED’s the brightness has been increased.. thank you..

  • CHETAN says:

    OK sir thank you..

  • Seetharaman says:

    Hi Chetan the same circuit will do. no change is required. As the change in current flow through the LEDs are marginal you will not practically see any brightness change.

  • CHETAN says:

    sir, for 36 LEDs (3volt @ 50mA) what modification I’ve to make..

  • Seetharaman says:

    Hi Capsun 24 Hi-bright white 4 Pin LEDs (3volt @ 50mA)in 2 rows will replace 11watt PL lamp. 40LEDs in 3 rows will replace 23 watts CFL lamp. May be for 15 watts you require around 30 in 3 rows to take care.
    Hi Chetan the same circuit will do for 3.2 volt 50mA Hi Bright 4 Pin LEDs..

  • CHETAN says:

    Sir, i want to add extra 12 LED’s that is total of 36 LED’s What changes I’ve to make..

  • capsun says:

    Dear Sir I want to replace 15w CFL with LED .How many LEDs i have to use to get same brightness as 15w CFL. What kind of LED should i use .Waiting for reply

  • Seetharaman says:

    Hi Chetan see the figure in the following site. you get the same in India.
    http://www.xbhp.com/talkies/universal-threads/11469-convert-ac-dc-bike-all-dc-47.html

  • Seetharaman says:

    Hi Chetan there is a PCB mount available for 150mA LEDs costing around INR 10, you have to use them for each LED.

  • CHETAN says:

    Sir, what I have to do for the heat sink..can you give me some suggestions please..

  • Seetharaman says:

    Hi Chetan you have to use the PCB with heat sinking track meant cooling these LEDs.
    Hi Anish Please refer the General purpose PCB
    http://www.delabs-circuits.com/cirdir/electric/electric2.html

  • Anish says:

    Thanks for the reply sir, definitely the bread board is my fault. I have the correct components. where do we get glass fiber pcb’s? and how do they look like? this is the first time i am hearing that name..

  • CHETAN says:

    Sir, the LED specification are:-
    Max. Forward Current: 150mA
    Max. Forward Voltage: 4.0V
    Working condition: -40°c~+60°c

  • Seetharaman says:

    Hi Anish phenolic bread boards insulation value can handle say up to 100 volt but not greater than that. Hence you use a general purpose glass fiber PCB which can take care. Check the diodes and electrolytic filter capacitor and the 1uF capacitor it should be rated for 400volts. ensure that you are using high bright white LEDs with 50mA @ 3.2 volts.

  • Anish says:

    Hi,
    I assembled the circuit, and when powered, the .5 watt resistor connecting the bridge and mains power burnt..(and was burning till i cut the power).. cant troubleshoot the problem.. what may be the possibilities? My friend suggested not to use it on the bread board..
    IMO, using bread board is the fault?

  • Seetharaman says:

    Hi Capsun For 16 LEDs you have to use an electrolytic filter capacitor of 220uF 63 volt use 2nos 33volt 1watt zener diodes connected in series and parallel to filter capacitor as surge protector. Use 2uF capacitor instead of 1uF in the supply input.
    Hi Chetan Check your LED specifications. test one led with 80mA constant current if it is getting heated up, you require PCB type heat sink for your LEDs. LEDs are around INR30 and the special PCB is INR10.

  • CHETAN says:

    Sir, the LEDs are becoming very hot..

  • capsun says:

    Dear Sir how to choose the voltage of the electrolyte capacitor .I want to connect 16 LED in series (3.2V@ 130mA).What other components i have to change.Waiting for reply.Thank u

  • Seetharaman says:

    Hi Chetan no change is required the same circuit will do.

  • CHETAN says:

    Sir, what changes I have to make to get 80mA..

  • CHETAN says:

    Ok sir i will use polyester type.

  • Seetharaman says:

    Hi Chetan you have to use non polar type, since it is used in AC circuit, getting 1uF non polar electrolytic will be difficult but 1uF polyester is available in plenty in the market, which you can comfortably use.

  • CHETAN says:

    Sir, can i use 1uF 400v Electrolytic capacitor or polyester type capacitor.

  • CHETAN says:

    Thank You Sir…

  • Seetharaman says:

    Hio Chetan for 80mA LEDs no change is required.

  • CHETAN says:

    Sir, i want to get 80mA because 120mA will be high for those LEDs.. So what modification i have to make.

  • Seetharaman says:

    Hi Chetan you can use the same circuit with 24 LEDs of 3.2 volt 120mA 8mm straw hat LEDs. the total power consumed by 24 LEDs will be around 10watts (with 1.68uF).

  • CHETAN says:

    Sir, so that how much current it will dissipate in each LED and can I use 8mm 0.5 watt straw hat LED..

  • Seetharaman says:

    Hi Chetan increase 1uF polyester to 1.68uF(add a 0.68uF 400volt parallel to 1uF)

  • CHETAN says:

    Sir, I want to make another circuit…
    In the above circuit can i use 8mm 0.5watt straw hat LED which can withstand upto 100Ma..

  • Seetharaman says:

    Hi Jawad use Light from scrap circuit you can use up to 13LEDs without changing any component.

  • jawad says:

    dear sir,
    I want to diagram which used 8 Leds on direct 230 vac

    Thanks,

  • vysakh says:

    @seetharaman, what happen to john??? No new posts here and one of my post under pending?

  • Seetharaman says:

    Increase 1uF to 1.64uF (use 2nos 0.82uF 400volts in parallel). reduce 100 ohms to 47 ohms 2watts. all other components require no change.

  • capsun says:

    Dear Sir I want to connect 10 LEDs (3.2v@ 150mA) in series .Pls tell me what changes shall i make in the circuit.Waiting for reply

  • CHETAN says:

    Thank you for your kind response sir.

  • Seetharaman says:

    Hi Chetan This circuit will consume around 2.5 to 3watts.

  • CHETAN says:

    Yes sir, the LEDs are getting little warm.. Sir, i want to know how much watt it will consume..

  • Seetharaman says:

    Hi Chetan readings are looking alright. run the light for about 2 to 3 hours. switch off and check the leds are they little warm or hot. it should be just little warm indicating everything is fine.

  • CHETAN says:

    Sir, I have used 24 LEDs. The DC voltage and current across EACH LED is 3.14 volt and 17 mA.

  • Seetharaman says:

    HI Chetan how many LEDs you have used? If possible measure DC voltage across one LED. With 1 or 2 LEDs it will be 24mA. with 24LEDs it will just less than 20mA.

  • CHETAN says:

    Hi sir, i constructed this circuit by using 0.33uF capacitor for 3 volt 20mA LED’s as you said, and they are very bright I don’t know how much current is flowing through those LED’s..

  • Seetharaman says:

    Hi Adru to get 40volt at 1amp you require around 12uF 350volt AC capacitor which will be rare to get and will be quite expensive. these circuits are suited for a maximum value of 2.2uF capacitor i.e. max 120mA at 40 volts. Hence for higher currents use transformers or switching supplies which are best suited.

  • Seetharaman says:

    Hi Chetan reduce 1uF to 0.33uF, no other change is required

  • Chetan says:

    Sir, i want to connect 3v 20mA Leds what modifications I have to do. please reply sir because I will construct this one.

  • adru says:

    WOW wat an active post & itz being one year nearly;regards for sir.seetharaman,mouly,japanjot.
    i hv one question:
    can v use this circuit as a transformerless dc powersupply for digital circuits,say design it for 40v 1A and placing an LM317 for varying the dc output voltage 1.2-37v.

    Atually i dont want bulky transformers :-p

  • Seetharaman says:

    Hi Rajesh 474K, first two are integers like resistance code 4 indicates 10 to the power four as multiplier (simply add 4 zeros) hence it is 470000 pF or 470KPF or 0.47uF. K stands for 5% tolerance and J stands for 5% tolerance.

  • Rajesh Misra says:

    Sir, how can we read the coding in Polyster capacitor? 474K/400v, 400V474J…etc….

  • Seetharaman says:

    Hi Misra 25mA LEDs will get damaged.

  • Rajesh Misra says:

    sir,
    can i use 50mA & 25mA LED’s mixed in these circuit? is there will occur any problems?

  • Seetharaman says:

    Hi Benny if want full kit you can contact DJR Electronics Chennai. 04442028443, or components without board from Vegakits Mumbai.

  • benny says:

    Dear Mr.Seetharaman sir, i am interested in this circuit very much… but i am located in a rural area of ponpara ….so the scracity of such electronic components is facing here,,,,, sir, are you a shop dealer of the electronics goods/ electronic items…? i am ready to make payment for the components of the device / please tell me where i can get these components by courier? i am ready to make payment in advance. So please…please help me////

  • Seetharaman says:

    hi Nikolas the bridge circuit is already corrected in the above diagram. what is shown now is correct

  • nikolas says:

    Sir Seetharaman, I’d like to ask a silly question (Im a newbie in electronics):
    Why the bridge should be rotated 90 degrees clockwise? Is the bridge differ from http://www.circuitstoday.com/mains-operated-led-lamp?
    Thanks.

  • Seetharaman says:

    Hi Meodenmatula Use 1uF only or else you will loose your LEDs soon. with 2.2uF the current will be greater than 110mA for 50LEDs.

  • meodenmatlua says:

    Hi Seetharaman
    I want use 220 Volt AC with 50LED 50ma.
    Can i replace capacitor 1uf by 2.2uf. in addition, need to change anything else
    Thanks

  • Seetharaman says:

    Hi Capsun for 20 X 1 watt LEDs. Read my reply to Mouly but change capacitor to 4.2uF 400 volts instead of 3.6uF. Any way I will recommend you to connect 4nos 1 watt leds in series, like this you make five sets connect them in parallel and connect it to a readily available 12volt 2amp SMPS.

  • capsun says:

    Hello Sir,I want to make a compound light with 20 high power 1 watt LED’s.Iam new to electronics .what changes i have to make in this circuit.Please help me.Thanks in advance

  • Seetharaman says:

    Hi Mouly You have to use 3.6uF 400 volt in place of 1uF. Use 33 ohms 5 watts in place of 100 ohms. Change 10uF 160 volt to 47uF 400volts.

  • Mouly says:

    Dear Sir, I want to coneect 5 high power LED’s (3.2V @350mA) in series.Pls tell me what all the necessary changes i have to make in the circuit.Waiting for reply

  • Seetharaman says:

    Hi Mouly These depends on the make used. Reputed makes may even work for 5 to 10 years. For high voltage protection add 78volt 2watt zener (2nos 39volt 1 watt diodes in series)diode in parallel with 10uF.
    Hi Rajesh no change is required except 10uF from 160 volt to 250 volts. no cooling fan is required. use a PCB with thick wider copper track and with good quality soldering should help dissipating the heat generated nicely.

  • Mouly says:

    Dear Sir ,what is the life span of the poly capacitor,also the 10uf electrolytic capacitor.How long they work ?Can this circuit withstand high voltages?Waiting for reply

  • Rajesh Misra says:

    Hi Seetharaman sir, i created the above circuit for outdoor use with a 8 x 8 Matrix in a PCB, all the LED’s are 50mA. What are the other changes should i made in the above said circuit for the 50mA LED x 64 nos? please clarify the poly. cap values and other resistor/ capacitor values. I planned to place in a closed outdoor light fitting to safe it from rain. Should i add some cooling fan’s for the 64nos included? Please clarify…. thanks in advance for your valuable reply

  • Seetharaman says:

    Hi Mohanraj
    use both the foromulae for your calculation, use RMS value.
    the values are 230 volt 50Hz.
    use the formulae
    R = V / I (the voltage you want to drop with current flow required) AND substitute R in the following formula.
    f = 1 / (2pi R X C) to calculate capacitance.

  • mohanraj says:

    Dear sir

    How to calculate capasitance value and all resistor value in the above circuit diagram if there is any formula for each please replay me sir

  • Seetharaman says:

    Hi Arie this circuit is suitable for 50mA hi bright LEDS which can stand 75mA. If you are using Hi bright whie 25ma LEDs donot exceed 35mA. Hence I will prefer you to reduce 1uF to 0.47uF. Check 1N4007 diodes some consignments available in the market are bad, they cannot stans more than 100volt. May be 1N4002!?. my prototypes (10 pieces) still running safe at home. The brightness is much better than 11watt energy saver u type tube.

  • friend says:

    ARIE, dont use mic make diodes, use other makes which has thick leads. And the above ckt works without any problem if u use quality components check ur LED voltage and current this circuit is for 3.2v,50mA. if ur LED’s are 20mA it i’ll get fade soon…

    BENOY if u r using 2core cable for 4ft then the conductor loss may present. it,d be better if u use fine thin wire bcos it has less copper so loss ll be less

  • arie says:

    hi, I am trying to string it, for R.. I replace it with 1 watt. I tried it just two days … with the condition led to live, not hot component, but on the first day .. 8 led start to fade, for 16 other led is still burning brightly. And flame equal to 24 LED lights 7 watts, still less bright? and how many led to the pair to be burning brightly?. how the power output by 24 led?

  • Benoy says:

    Hi Seetharaman sir, Primarily a Hats off! I’m eagerly searching for a LED Lighting sys for my ‘dark’ room( actually an extension of my home is become cloudy with out proper windows!). I found it.. Am in doubt that can I set the 24 no. series with a 4 feet partitioning? ie, shall i set the LED’s series in 2 by lagging the 12 LED’s after 4 feet gap(with a 2 core cable? is it will make any wrong result? Please reply

    Thanks in advance

  • Seetharaman says:

    hi pramugan 5uF is capable of 360mA current. since you have used a 50volt capacitor it has become leaky above that voltage hence 50 / 3.2 = 16 LEDs can glow beyond that the capacitor should have become hot.
    with 160 volt capacitor 160 / 3.2 around 50LEDs. the filter capacitor is acting like a resistance at higher voltage.
    in the above circuit with 5uF 350volt capacitor in the input and 10uF 350 volt as filter you can connect 108 LEDs in series.

  • Pramugan says:

    when i ll be getting reply for my post

  • Kumar says:

    yes mouly calculate the capacitance value according to ur requirement.

  • Mouly says:

    Dear sir
    Is that possible to get output above 150mA so that i can light up high power LEds in series from the mains supply

  • pramugan says:

    sir my doubt is by changing filter capacitor will the output increase?. because i construct bridge with 5ufd 400v as input capacitor and 1000ufd 50v as filter it can able to lightup 16 LEDs i replaced the 1000ufd 50v with 63ufd 160v it can able to lightup 48 LEDs.(all connections in series). in general is that possible in similar circuits?

  • Kumar says:

    thank you sir

  • Seetharaman says:

    Hi Kumar use 2nos 40volt varistors in series in parallel with 10uF 160 Volt.47uF will get still hotter. use a good quality 160 volt or use 10uF 250volt. nothing is required at the bridge input if you ate using in DC.

  • Kumar says:

    the varistor avail is 40volt and next to that is 175 volt. instead of that 75 volt 1 watt and 3.3 volt 1 watt zener in series and in parallel with 47uf 160 volt( i replaced 10uf 160volt with 47uf 160volt bcos 10uf became very hot). And should i have to connect both mov at bridge AC input and zener at filter capacitor?

  • Seetharaman says:

    Hi Kumar Your poin 1 is ok, for SMD LEDs you can use normal components no need for smd components. you can use a 270 volt varistor across the bridge rectifier AC points( input surge protection). 2nos 30 volt 1w and 1no 18 volt 1w zeners connected in series in parallel with 10uF 160 volt capacitor(towards 1uF capacitor leakage protection) or you can use a 76 volt varistor if available readily. s10k320e is a 320 volt mov. should not give any problem not suited for this circuit as it may not protect.

  • Kumar says:

    •Hi sir, I tried your circuit its working great . i used 5mfd @ input for 150 Led’s. 50 in each row.

    1. how to specify the suped flux 5mm Led which
    is displayed in the above picture 07 does it has any model number?.

    2.if i use SMT Led can i use the same circuit or should i have to go for SMD components?

    3.how to use VARISTOR in the above circuit ?

    Thanks a lot for sharing ur valuable time and ideas..

    i connected a mov S10K320E b/w ph and netural but it made all the LED’s to dim so i removed it what is the value i should go for and where to connect it.

  • pego says:

    i don’t have 1uf 400v. could i use 1uf 250v? is it safe or will be burning?

  • Kumar says:

    i connected a mov S10K320E b/w ph and netural but it made all the LED’s to dim so i removed it what is the value i should go for and where to connect it.

  • Kumar says:

    Hi sir, I tried your circuit its working great . i used 5mfd @ input for 150 Led’s. 50 in each row.

    1. how to specify the suped flux 5mm Led which
    is displayed in the above picture 07 does it has any model number?.

    2.if i use SMT Led can i use the same circuit or should i have to go for SMD components?

    3.how to use VARISTOR in the above circuit ?

    Thanks a lot for sharing ur valuable time and ideas..

  • srundenggosong says:

    thanks nice posting

  • RAHUL says:

    yup thank u…

  • Seetharaman says:

    Hio Rahul the required effective 750 ohms is given by the capacitor(this will be effective resistance value of the capacitor at 50 Hz). There is no need to calculate 100 ohms 2nos value, as it will be standard for all circuits to limit in rush current to 1amp max. hope i am clear

  • RAHUL says:

    i got it sir 4.7mfd and resistance is b/w 200 to 470k

  • RAHUL says:

    sir waiting for ur reply plz help me out

  • RAHUL says:

    Sir am waiting for your reply kindly plz help me out

  • RAHUL says:

    thank u sir actuallt i need to improve brightness so am adding 150 led’s of 3.5v@ 25mA 50 in each row. am confused with the calculation.50×3.5=175. 230-175=55. 3 rows in parallel so 25mAx3=75mA.since parallel current varies. so 55v @ 75mA, 55/0.075=733.34 ohms. in f=1/(2*pie*R*C) R= v drop/I =55/.075=733.34 ohms. then 50=1/(2*3.14*733.34*C) =4.3mfd. therefore standard values are 750 ohms and 5 mfd is this correct?.

  • Seetharaman says:

    Hi Rahul you require 1.2uF and 200 ohms only 3k is not required. say you are using 16 LEDs of 3.0 volt 50mA 48 volt at 50 mA you have to drop 230 – 48 volt that is 182 volt at 50mA (RMS value used for calculation) hence 182 / 0.05 that is the series resistance required. 3.64K ohms. this is Xc now calculate the required C from this freq is 50Hz. for 50 Hz thumb rule for filter capacitor is 1000uF per amp of load, for 50mA load 50uF is required to reduce flicker. 10uF is practically found sufficient without any noticeable flicker. To avoid switch on surge current to be well within the limit of 1amp 220 ohms is the preferred value.
    Hi Ketha it is possible. we are trying to limit it to 90 high bright LEDs (30 in each row)with a rotational possibility of 90deg continuously, it will appear soon.

  • sathya says:

    sir i used 25 white led in a energency light light and i used 5 x 1.2v 2200mah batteries and i connected 4.7 ohm’s 10watts resistance due to this the battery drains very quickly how to modify the circuit. charging side is working good.but load side is worst. plz help me out.

  • rahul says:

    how to calculate filter capacitor sir (ie. 10mfd 160v). i designed a circuit with 680 and 1000mfd 50v for 16 led’s. without knowing the calculation only i did but its working fine, but i think its a bigger value for the ckt. i used 105j 400v poly parallel with 1k ohm and 56 ohm mext to the bridge. i just want to know how to calculate it.

  • rahul says:

    if my calculation is correct t have to use 1 or 1.2mfd and 3k resistance. before bridge.isn’t sir. and the remaining two 100 ohm’s and filter capacitor should remain the same. am i right sir??

  • Seetharaman says:

    Hi Rahul you kindly go through my comments dated nov6th and 16th will give you the details

  • Rahul says:

    from input
    1st set |->->->-|
    2nd set |->->->-|
    3rd set |->->->-|

  • Rahul says:

    hi sir
    i just want to know that how to calculate poly capacitor farad and voltage. and if i construct the circuit for 60mA is that possible to connect 50 led in a set and 3 sets in parallel. |->->->-|
    |->->->-|
    |->->->-| like this .

  • Seetharaman says:

    Hi Prasanth intially like energy saver lamp it will be expensive but on the long run it will pay back on electricity expenses.
    Hi Dhruv you can use higher wattage resistances if space is not at premium.

  • dhruv says:

    hi sir im new to electronics and i like your project very much i just want to know that in any circuit or in your circuit also can i use high wattage resistor even circuit required low wattage resistance….in ur circuit can i use both 100 ohm resistor or 0.5 watts….instead of one 0.25 watt 100ohm resistor…waiting for ur reply sir

  • Prashanth says:

    Thanks a ton Mr.Seetharaman!
    I was searching for such a thing for a long time. I will now replace all the bulbs in my home :) wondering if it would be economical to do so.

  • UDAYAKUMAR .S says:

    Dear Sir,

    The LED circuits are very interesting and use full to me. I hope you will publish low cost LED circuit diagrams later.
    Thanking you
    yours faithfully,

    UDAYAN

  • Seetharaman says:

    The LEDs are High bright white 3volt 50mA type. 1uF should be non electrolytic, paper, polyster or polycarbonate. Open circuit DC at bridge rectifier output will be around 350volt. but if all LEDs and components are connected it will be around 72 to 75 volts only.

  • rahul porwal says:

    i also tried the new version but i am getting the voltage about 230 v at load.
    is it correct?

  • rahul porwal says:

    ok thnx sir,

    Q…. we have to use the electrolytic capacitor{1 mf 400v} only or we can use any other.
    and plz tell me the voltage at the o/p of bridge,and also tell me the voltage and current rating of the LED.

  • Seetharaman says:

    Hi Rahul there was a mistake you kindly see my earlier comment of june 26th on that, it has to rotated clockwise by 90deg. otherwise the circuit is ok and functioning well.

  • rahul porwal says:

    how the bridge is working ?
    plz tell me

  • eason says:

    Hi Sir, can i add LEDs until it has 36 LEDs in series? What are the components value to change?

    Thank You
    Eason

  • Seetharaman says:

    Hi Japanjot you can suitably adopt battery charger using SCR circuit appeared earlier in circuitstoday. use the following link.
    http://www.circuitstoday.com/battery-charger-circuit-using-scr

  • japanjot says:

    ok sir,thnx for the battery charger advice, sir also tell me how to make it overcharge prtective, like the battery should stop charging when the battery is full

  • eason says:

    Hi Mr Seetharaman, can i add more LEDs to increase the brightness? Can i have a circuit that have two parallel strings with each strings having 20 LEDs(Total LEDs will then be 40).

    Thank You

  • Seetharaman says:

    Hi Murali use both the foromulae for your calculation, use RMS value.
    the values are 230 volt 50Hz.
    use the formulae
    R = V / I (the voltage you want to drop with current flow required) AND
    f = 1 / (2pi R X C)

  • Seetharaman says:

    Hi Murali you can use as indicated by me on 15th Nov.
    Hi Satyam this is a standard formula available in any text book. f=1/(2*3.14*R*C)

  • Satyam says:

    Hello Sir, your formula is not so clear, Is it f=1/2*3.14(pi)*R*C OR f=1/(2*3.14*R*C)

  • murali says:

    all leds r 3.2v max 3.6v

  • murali says:

    all leds r 3.2 to 3.6 voltage sir

  • Eason says:

    Hi Mr Seetharaman, can i add more LEDs to increase the brightness? Can i have a circuit that have two parallel strings with each strings having 20 LEDs(Total LEDs will then be 40).

    Thank You

  • murali says:

    thankyou sir yes iam planning to use 5mm 3v 20ma, help me for 24led & 36led of same rating

  • Seetharaman says:

    Hi Murali use 0.68uF for 1uF all others don’t require any change. (hope you are planning to use 3volt 20mA white LEDs).

  • murali says:

    i want to connect 48 5mm leds of 20ma each what should i change in this circuit please tell me sir

  • Seetharaman says:

    Hi Japanjot yes you can make it. 1.3AH battery requires 130mA charging current now calculate for 130mA RMS current that is 230 / 0.13 with 1.8mF you can get it. if not you can use available 2uF or 1uF 2nos in parallel. instead of LEDs you connect the battery. use a 4.7 volt zener to limit the battery terminal voltage from raising.

  • japanjot says:

    ya i checkd they are of 3.2v 25ma, sir how to charge 4v battery of 1.3 amp, i want to charge it around 150ma per hour, i want to make transformerless supply like this for it.thank you

  • Seetharaman says:

    Hi japanjot congrats. hope the LEDs are 3.2 volt 25mA that is 0.025A, your calculation is also correct for peak current calculation.

  • japanjot says:

    and sir while calculating R for f=1/2pi.R.C the voltage i used is 320v for calculating v in v=ir,320 v dc v

  • japanjot says:

    sir i am running 100 blue leds in series, and all i modifies is just i added 3.3uf cap parallel to 1uf cap in your circuit, the total power is around 5w, and leds are quite bright
    the leds which i used were 3.17 to 3.20v @ 0.22-0.28 ma
    thnks sir 4 this usefull ckt

  • Seetharaman says:

    Hi Japanjot you try and give me a feed back about your success.

  • japanjot says:

    *=>>sir with 2uf cap can i connect 60×2 chains of blue led of 25-28 ma ???? total of 120 leds?

    *=>> sir what is the maximum limit of dc voltage which we can use for leds ??? when i check o/p voltage withot load its around 345v, so can i use 100 leds in series(3v each and 30ma current) to utilise 300v out of 340 with 2.4uf capacitor??

  • Seetharaman says:

    Hi Japanjot. The 100 ohms are only for input current limitation they donot require any change. The discharge resistance can be any value from 100 to 470 K such that they dont add up the current flow and dissipate power. 10uF will remain the same.

  • japanjot says:

    *=>>sir with 2uf cap can i connect 60×2 chains of blue led of 25-28 ma ???? total of 120 leds?

    *=>> sir what is the maximum limit of dc voltage which we can use for leds ??? when i check o/p voltage withot load its around 345v, so can i use 100 leds in series(3v each and 30ma current) to utilise 300v out of 340 with 2.4uf capacitor??

    *=>> how to calculate capacitor’s discharge resistor. and other two resistors and their wattage (100ohm 0.5w in your ckt)
    thank you sir , you always reply with patience

  • japanjot says:

    one more thing sir, how much volts can we use for leds, like for 24 we using 72 volts , can we use till 230 volts for 76 leds?

  • japanjot says:

    ok thank you sir now my circuit is working fine i am using your same circuit with 2 parallel chains of 28 blue led total 56 leds, they are absolutly fine. thank you

    sir how u calculate resistance which is parallel to capacitor?

    and if the dropping resistor value comes to be 6 kohm, then do i have to change all the 3 resistance to 6 k ohm or the one which is directly connected to 230v(100 ohm in your ckt) or the resistance which is next to the bridge(100 ohm in your ckt) ?

    and the 10 uf cap would remain same in all the cases i guess?

  • Seetharaman says:

    Hi Tony with the recommended LEDs connected the terminal voltage cannot raise beyond 72 volts. by using a low current LEDs the drop across capacitor 1uF will be less hence high voltage will appear across the capacitor and inturn on LEDs. as lesser drop across capacitor higher voltage has devoloped highed current for the LEDs hence they have blown.
    please go through the calculations i have given earlier today.

  • tony says:

    Hi Seetharaman,

    If rotated by 90deg than the output voltage at this point capacitor 10uf 160v will be very high 228v – 230v without attached to LED’s and this capacitor start become hot.

    No wonder Mr.Japanjot LED’s burn.

  • Seetharaman says:

    Hi Tony in my above circuit the bridge rectifier has to be rotated by 90deg it is a mistake.

  • tony says:

    Hi Seetharaman,

    I tested all the component is o.k, it is because of the diode direction (1N4007) ?

  • Seetharaman says:

    Hi Tony it looks your capacitor is shorted, reason without load the peak terminal voltage can raise to 230 X 1.414 = 325 volts. hence you have to use a 400volt capacitor without load. if loaded 160 is sufficient as you are likely to get around 75volts.

  • tony says:

    Hi Seetharaman,

    I try to assemble the circuit as above and I measure the DC voltage 0 no reading at capacitor 10uf 160v, do I miss something I’m using 1N4007 diode. What is the reading at this point before connecting to LED.

  • Seetharaman says:

    Hi Japanjot This circuit will work with 3 volt 50mA BRIGHT WHITE LEDs. If you want for any other current you have to recalculate. Say you want to use 25 blue LEDs of 4 volt @ 25 mA. 4 X 25 = 100volt at 25mA your supply voltage is say 250volt at 50Hz. Now you have to drop 250 – 100 = 150 volt. 150 volt the current through is 25mA then the dropping resistance value is 150 / .025 = 6 kilo ohms. by using the formula the capacitance required is 0.53uF use a standard nearby available value 0.47uF, by which the current will get reduced to 22mA which will not reduce the glow appreciably, also safe for the LEDs to be driven with slightly lower current.

  • japanjot says:

    sir happy diwali to you and your family, wish u had eco frndly diwali with led lyts :-)

  • japanjot says:

    helo sir, i made dis circuit with blue 25 leds it workd fine for first time, but as i switchd of and again powerd on all the leds got burnt :-( …… sir wt to do??
    sir plz explain me how to imply your formula f =1/2piR.C,
    there are 3 resistances, two capacitors in this circuit ,please tell me how to calculate each component value.

    also tell me how to calculate led number acording to capacitance, and how to calculate capacitane according to voltage

    please xplain with example, i am very eager to learn and i dont want to burn leds again :-) .
    thank you again sir for your concern

  • Seetharaman says:

    Hi Tony any size 3volt 50mA LEDs.

  • tony says:

    Hi Seetharaman,

    This circuit suitable for 5mm or 10mm LED ? Thanks

  • Seetharaman says:

    Hi Tony you can use switched mode power supply available for 12 volt halogen lamps(they are available in various load ratings). you can use 4 hi bright white LEDs in series and connect it to SMPS through 5 ohms resistance in series with each group as currnet limitting resistance. each group requires 12 volt at 50mA. If you use 100 groups you require 60watt SMPS to take care of all these 400 LEDs. You can increase or decrease in the order of 4 LEDs group.

  • tony says:

    Hi Seetharaman,

    Thank you Sir for your valuable information and if want to increase the LED from 24 nos to maybe 300 or 400 nos how to do it like what China manufacture sell it call LED Flood lamp?

  • Seetharaman says:

    Hi Tony this has been installed in Hotel Lounges and Rest rooms and they are working for the last 1 year without any problem. initially we had problem with 1N4007 MIC make(light will become dim and start flickering). and the electrolytic capacitor(which use to get ruptured). We have switched over to Philips and Keltron, since last one year no problem at all.
    Hi Luis for 115volt 60Hz you replace 1uF 400 volt with 0.82 uF or use the same 1uF increase LEDs to 35 nos.
    If you want to use one LED for just mains indication use a 4.7 K resistance 3 watts in series and a diode 1N4007 in reverse biased condition across LED. you can use 0.47uF for 1uF and use only 1LED all other components are same.

  • tony says:

    Hi Guys out there,

    So far how many of you try this circuit and can last how long the LED’s, 6month or 5 years?

  • Luis Zunico Zuñiga says:

    Les agradeceria me indicaran como calcular los valores de los componentes para un suministro de Red de 115 V AC

  • Seetharaman says:

    Hi Japanjot you can use 2volt (1.7 volt at 20mA)red leds SAY YOU WANT TO USE 40NUMBERS then the voltage is 68 volt at 20mA. retain increase 100 ohms before bridge rectifier as 220 0hms and capacitor as 0.33uF (330nF)
    For yellow and green (they are 2volt devices at 20mA)say for 35 LEDs 35 X 2 = 70 volts. the same modification will do.

  • japanjot says:

    what would be the changes to be made if i want to install red led of 2v each or yellow led of 2.2v each in this circuit insted of white 3.5v

  • Seetharaman says:

    Hi Japanjot these 28 to30mA LEDs are safe with 25mA hence in the above circuit you have to change 1uF 400 volt to 470nF 400 volt and 100 ohms resistance before bridge rectifier as 220ohms, other components kept un changed. for 60mA change 1uF to 1.2uF no other component requires change. the values are 230 volt 50Hz. use the formulae R = V / I AND f = 1 / 2pi R X C

  • Rakesh says:

    Seetharaman sir,
    How can I measure its wattage, My Multimeter is a low profile one, it can only detect ac rms value of voltage and dc voltage and dc current.

  • japanjot says:

    one more thing, i checkd my leds , they are of 28 to 30 ma current each what to do?
    any changes are to be made?

    and can u tell me the changes to be made for total 60 ma output

    please answer all my question in this and my last post…
    really thanks alot

  • japanjot says:

    ok thnx sir,

    1): what would be the value of frequency here would it be 50?, and
    2):how you set the current in this circuit, i mean wts the formula for setting desired current like 30 ma, 50, 100, 150 ma etc
    3):what would be the changes to be made if i want to install red led of 2v each or yellow led of 2.2v each in this circuit insted of white 3.5v…

    thnk you sir, and would be eagerly waiting for your helping hand

  • Rakesh says:

    Seetharaman,
    I’ve used 0.68 uF instead of 1uF for the mains supply and no resistance with it. Yet it worked, with little less brightness. There was 48 LED-s in series. I used a bridge rectifier package.
    I will be happy if there is any brightness control, and what is the probable power consumption?

  • Seetharaman says:

    Sorry Japanjot. there was a mistake. it should be f = 1 / 2pi R C. f is frequency R resistance and C is capacitance

  • japanjot says:

    sir what is f and F in the formula

  • Seetharaman says:

    Hi Japanjot you can glow 60nos 50mA high bright white LEDs in the above circuit with 2uF capacitor.
    The formula is f = 1 / 2 pi F C

    • Nadir Hasnain says:

      Sir

      Please Help to know how I can Calculate Current Flow of Power supply Output, and each Component Value (Rating), Also can i Connect LEDs in Parallel instead of Series to avoid circuit failure due to even one LED goes faulty, This can be achieve by Increasing Current and decreasing Voltage, Can you please help me to know calculation.

      Also if LED rating is not mentioned on LEDs so how i can know its Current and voltage rating

      Thanks
      Nadir Hasnain

  • japanjot says:

    sir how many leds can glow with 2 uf cap? can u tell me the for mulas with which u calculate resistances and capacitance for this circuit.thank you again

  • japanjot says:

    thank you sir for your quick reply

  • Sethumadhavan says:

    Sir,

    Its working fine. Thank you.

  • SAJU says:

    sir,

    I have assembled the circuit and working fine. But The LEDs gets faded out within 2-3weeks time. Is there any thing wrong

  • murali says:

    thankyou sir

    murali

  • Seetharaman says:

    Hi Murali nothing requires any change other than capacitor. For 0.82 you can use 680K and 100K in parallel. for 1.2k you can use 680k and 470k in prallel. a small difference in current will not matter much. With 680k and 19LEDs the current flow through leDs will be 48mA which is ok.
    Hi Japanjot for 50 LEDs you replace 1uF with 1.5uF. for 100 LEDs use two circuits as above with 1.5uF capacitors

  • murali says:

    i connected 19 led with 680k capacitor its working will there be any problem or i have to change anything in d circuit

    regards
    murali

  • murali says:

    iam not able to get 0.82uf & 1.2uf capacitor a got only 220k, 470k, 680k, capacitor what should i do

  • japanjot says:

    sir was looking for project lyk yours for very long, sir what to change for 100 leds and 50 leds.

  • Seetharaman says:

    Hi Murali for 19 LEDs reduce capacitor to 0.82uF, a standard value or use a 15volt in series with th LED loop.
    For 42 LEDs increase capacitor to 1.2uF you will get around 47mA current there will not be much of brightness reduction can be noticed.

  • murali says:

    i bought 2 led plastic housing but in that i can only fix 19 & 42 leds of 50ma what should i change in this circuit thanks for ur reply

    regards
    murali

  • Seetharaman says:

    Hi Sethumadhavan check the capacitor 10uF for a short. disconnect 10uF measure the pulslating DC with AC and DC content with a multimeter if it is ok replace the 10uF after connecting LED circuit energise it should work. you can use without 10uF also for a short duration during check. without this also LEDs will glow. this is used for switch on surge protection. finally connect it back. (check each LED seperately with 3 volt supply – use a lithium disc cell for fast checking)

  • Sethumadhavan says:

    Hello Sir,

    I’ve noticed already before assembly and done it in right way.

  • Seetharaman says:

    Hi Sethumadhavan the above bridge circuit is wrong kindly rotate it by 90 deg. this may be the reason

  • Sethumadhavan says:

    Thank you Sir,

    I’ve used bridge instead of 1N4007. The LED’s are not glowing. How I can trouble shoot it? I’ve disconnected the supply to the LEDs but not receiving any the voltage? Can you pl guide me?

    Regards,

    Sethu

  • Seetharaman says:

    Hi Sethumadhavan No load output voltage will be mains voltage X root 2. that is approximately 350volts DC. which will damage the capacitor instantly or if the capacitor is ok then the current limitting resistors 100 ohms will get burnt.

  • murali says:

    thank u sir for ur reply

  • Seetharaman says:

    Hi Murali you require to change only the 1uF capacitor.
    For 15 LEDs it should be 0.77uF ( 2 1.5uF in series)and for 36 LEDs it should be 1.2uF

  • Sethumadhavan says:

    Dear Mr. Seetharaman,
    What will be the no load o/p voltage and the current (disconnecting the LED) across 10µf / 100V capacitor?

  • murali says:

    thank u sir, i tried this 24 leds circuit today its working fine & very bright/ for 15led & 36 led of 50ma what should i change in this circuit. waiting for ur reply i once again thank u sir

  • ravi says:

    thankyou sir

  • Seetharaman says:

    Hi Ravi you want to use this circuit with the UPS of computer for the glow, yes you can go ahead

  • ravi says:

    Hi sir can I use this circuit for sinewave inverter those are used for computer.

  • Seetharaman says:

    Hi Patrick since all the LEDs are in series you require around 72 volt DC, hence we have to redesign the circuit to suit either 6 volt or 12 volt battery. i will keep in mind for the future project.

  • Patrick Vaz says:

    Hi Seetharaman,
    This is a good circuit(transformer less) mains operated LED CIRCUIT. but just to take a step further if a Battery say 6v 4ah is added to make it mains operated LED with battery back up. would there be much changes required in the circuit.
    Regards

  • Seetharaman says:

    Hi Ravi Sorry the bridge rectifier is drawn wrongly. please rotate it by 90deg.
    Pl refer to my comment dated 26th june

  • ravi says:

    Good evening sir if Bridge connected as usual what happen’s, please suggest me

  • Mouly says:

    thanks Sir

  • seetharaman says:

    Hi Mouly with capacitance in circuit it is +0.3 hence you have to add inductance also. this will become bulky. to avoid that you can shift to switched mode power supply then you can achieve almost unity power factor but the circuit will become expensive.

  • Mouly says:

    Can the power factor of this circuit be around 0.9.how to improve power factor of this circuit.In simulation the power factor of above circuit is just 0.3 .how to make it 0.9

  • seetharaman says:

    Being a capacitive load power factor will be positive and quite low in value. The power measured was so low and hardly 3watts.

  • Mouly says:

    What is the power factor for this circuit Sir.What is the best power factor in case of AC to DC conversion circuits without using transformers.Please explain me about power factor.Waiting for reply

  • seetharaman says:

    Hi KVS, Please refer my reply on 26th june on correction to bridge rectifier it should be rorated be 90 deg clockwise. you may please go ahead it will work nicely. See my prototype units photographs.

  • kvs says:

    is this circuit is correct? in the bridge side sir? the input ac supply is connected to anode and cathode point of the bridge circuit in other circuits.

    please tell me sir. i’m bought the all components and assembled. but finally i check the circuit, i got this doubt.

    please tell me soon.

  • mouly says:

    Thanks for your response Sir

  • Seetharaman says:

    It is the peak charge current limitation for the capacitor. wihtout this it’s internal resistance will be zero initially hence the initial charging current will become infinite exploding the capacitor instantly. refer capacitor manufacturers catalog for the recommended max current.

  • mouly says:

    what is the formula to calculate the resistor to limit the peak charging current

  • Seetharaman says:

    Hi Mouly it is to limit the peak charging current to well within 2Amps

  • mouly says:

    How to calculate that resistor (100 ohms) value.Waiting for reply

  • mouly says:

    Thanks for your response sir why is another resistor is connected to other end of 23o volts(100 ohms).waiting for reply

  • Seetharaman says:

    Hi Mouly use the standard formula f = 1 / 2 pi r c. Discharging resistance must be capable of discharging the capacitor in few seconds.
    1F will give 1A for 1sec.

  • mouly says:

    Sir,
    How to calculate the value of the ploy capacitor for the above circuit like wise the resistor value in parallel to it.Waiting for reply Sir

  • seetharaman says:

    Hi Ganesh
    Hope you require this for 120Volt 60Hz then the only change is increase 1uF 400volt to 3.3uF 250 volts even 400 volts can be used. All other components are same

  • Ganesh B V says:

    Sir,
    How to use this circuit for 120 v power supply?
    Please configure

    Thanks

    Ganesh

  • mouly says:

    Thank you Sir

  • rakesh says:

    thanks for ac led circuits

  • seetharaman says:

    Hi Mouly If the LED strips are for 25mA, then you can connect two in parallel. if it is for 50mA each then you have to double the input capacitor to 2uF.

  • mouly says:

    Thank you for you response sir.Can I connect two parallel led strips each with 24 leds if so should I change any components.waiting for reply

  • seetharaman says:

    Hi Mouly 470K to discharge the 1uF capacitor after switch off. The resistances are for limitting the in rush current due to the 1uF capacitor. Since the circuit is for 50mA LED 100 ohms 1/4 watt is required, as the light is enclosed a 1/2 watts resistance to be used. 1uF capacitor is calculated from the Xc required for the current required and the voltage drop required. the 10uF capacitor is for to get a slow raise of voltage and current to LEDs to protect then as they are in series.

  • mouly says:

    Very nice circuit sir .How to calculate the components vaules.What is the use of 470k ,how to calculate similarly other two resistors.please let me know.waiting for reply

  • seetharaman says:

    Hi friends there was an some doubts about the circuit. Please note.
    . 50mA is the current through the circuit. That is 0.05 X 0.05 X100 That is 0.25 watts hence 1/2 watt will do. similarly for 470K 0.25 watts will do.

    With the capacitor value shown the limitation is 24 LEDs.

    In the place of bridge 400C1 bridge you can use 4 nos 1N4007 since its PIV is 1000volt.

    Minimum PIV required is 600volts.

    The 100 ohms resistances used are for surge limitting
    470K to discharge the capacitor and the 10uF in the DC to protect during initial surge current. All the components used have purpose plese donot delete any you may loose your valuble LEDs on the long run.

  • deepak says:

    why are all the LED’s connected in series..the voltage across each of them will not be the same…isn’t it better to connect all the LED’s in parallel with an appropriate resistor so that all LED’s have the same voltage across them..

  • join says:

    circuit radio
    circuit fm am

    • Avik says:

      Hi,

      I am made this circuit. I am used 105k 400v ppc caps, 1m 1/4watt resistance, 4 IN4007 Diode, 10uf 450V Electrolytic caps,2 nos of 100 ohms 2watt resistance and 15 nos of 8mm LED 3.2v 120ma.
      circuit works fine but 100 ohms 2 watt resistance got heat up lightly.
      is it any problem on that please help me out..