LED lamp circuit from scrap

admin November 22, 2011 161 Comments

Power saving LED lamp from your scrap box.

This circuit is designed by Mr Seetharaman Subramanian and we are very glad to publish it here. In this article he is showing a method to convert a broken/defunct CFL into a LED based power saving light.

This is just a LED lamp circuit that can be operated from the mains voltage. A string of five LED is driven using a capacitive transformer less power supply. In the circuit 0.47uF/400V Polyester capacitor C1 reduces the mains voltage. R1 is a bleeder resistor which drains the stored charge from C1 when the AC input is switched OFF. Resistors R2 and R3 limits the inrush of current when the circuit is switched ON. Diodes D1 to D4 forms a bridge rectifier that rectifies the reduced AC voltage and C2 acts as a filter capacitor. Finally Zener diode D1 provides regulation and the LEDs are driven.

Photos.


Circuit diagram.

Seetharaman’s words about the circuit: I am sending you a table lamp made from defunct energy saver lamp with broken tubes. CFL converted into LED lamp. Most of the components will be available in ones scrap box. Few components available in the CFL PCB also can be used.

Procedure

1. Carefully remove the broken glasses

2. Open the assembly carefully

3. Remove electronics and discard

4. Assemble the circuit in dot matrix PC or on a 1mm laminate sheet.

5. Cut a round laminate sheet with (scissor)

6. Mark the position of the 6 round holes on the sheet

7. Drill the holes to suit the LEDs to flush fit in the six holes

8. Use a dab of adhesive to keep the LED assembly in position

9. Close the assembly

10. Ensure the internal wiring does not touch each other

11. Now test on 230Volt AC

Your nice compact table lamp / puja room lamp / passage lamp is ready for use.

 

Comments
  • Abdul Khaliq Ansari
    November 13, 2015

    Sir, above said circuit is very good, I built and using in home, please let me guide for 1 Watt LED using 5 & 10 LED circuit pl.

    Thanks n Regards

  • ramadan
    March 6, 2015

    Can we modified the CLF (compact light florescent) circuit into induction heater circuit thank you

  • DEVDAS BHAKTHA
    February 25, 2015

    Sir, I liked your article ! Rarely people upload such clear concepts; your script, circuit details, explanation of it’s working, all are par excellence. Thanx ! Could you please send me expanation of how exactly a 230 V AC Mains Operated CFL driver circuit works, all with exactly in the manner you have now given for the LED ckt. Also, I want to know if CFL Driver and CFL Ballast are one and the same.

  • vikas sharma
    February 8, 2015

    what is the power of these LEDs used in this circuit?

  • Inderjeet singh
    February 7, 2015

    Sir i want to make a SMPS 12 volt 2 ampere circuit.

  • Inderjeet singh
    February 7, 2015

    sir what should i do if i want to increase the load upto 2 amperes. please guide me sir. I want this information urgently.
    Thanks.
    Inderjeet Singh

  • agentCrop
    February 4, 2015

    What is the voltage across 0.47uf capacitor and how is it calculated? According to 50mA, it is around 338V and but supply is 230V.

  • Kriti
    January 31, 2015

    hi sir,i am not getting 0.47uf 400v capacitor in indian market.anybody plz help me ,plz guide me to any online store in india

  • January 28, 2015

    sir, is there any circuit diagram for 10 watt led from AC power.

  • jerry
    January 10, 2015

    I want to connect 7 led’s ( 3v,350mA , 1watt led’s). so which part of the circuit is to be modified. please give details.

  • Rajesh
    November 5, 2014

    This circuit output total power is 4W

  • NARESH SINGH THAKUR
    November 1, 2014

    Dear Sir
    Thanks a lot for your circuits . Kindly suggest me a circuit diagram for SMPS 24 v 5 A to run led arrays.
    Regards
    Naresh

  • NARESH SINGH THAKUR
    October 30, 2014

    Dear sir,
    thanks for the circuit kindly tell me the wattage of LED can we use 1w LED
    . if not kindly suggest me the same circuit for 6 numbers of 1 w power natural white Led
    Regards
    Naresh

  • Mukesh Biswas
    October 27, 2014

    Hello…

    If 0.47uF 400 volt c\poly capacitor is not available then what Electrolytic Capacitor I can use in the same circuit….

    Please reply…

    • Kriti
      January 31, 2015

      i have same problem ,i am also not getting 0.47uf 400v capacitor in indian market.anybody plz help me ,any online store in india

  • October 10, 2014

    Sir, please tell me how increase a power of LED . I use five LED but the light is soo.. Dim

  • Inder Jeet
    September 4, 2014

    Dear Sir,

    I want to start the business of LED bulbs manufacturing. So i need the yours assist to develop the circuit of LED PCB.
    My concept it that we use 6 pieces 0.5 watt SMD for 3 watt LED bulbs. Everything’s going on right but in PCB circuit what kind of capacitors, Diodes and other parts will be working? I want to know in details.

  • AbdulBasith
    August 24, 2014

    Why this LEDs are parallel ?

  • Prashant
    August 24, 2014

    Hello sir, I want to make circuit of led bulb works on 240 v
    ac. With high brightness for house use so,please help me
    for construction.having 3 to 7 watt power with more lumen about 200 to 500 like 11 w CFL bulb.

    • seetharaman
      August 27, 2014

      You have to use 40 LEDs in series 3 volt 50 MA high bright LEDs to get the same or better illumination. 13 + 14 + 13 in series. Refer to our earlier high bright led project with 24 LEDs. The same circuit can be used for 40 LEDs without modification.

  • SOWMYA SREE
    August 22, 2014

    how much power this led lamp saves when compared to ordinary light

  • SOWMYA SREE
    August 22, 2014

    i got the output……….
    thanks for replying……..sir

  • vaibhav
    August 20, 2014

    seetharaman sir…
    please post at 100 watts MOSFET power amplifier
    it’s urgent …

  • SOWMYA SREE
    August 17, 2014

    can i give 230 volt supply directly to the circuit???

    • seetharaman
      August 19, 2014

      Yes it is rated for 230 volt sine wave not for square wave inverters; which may blow it.

  • August 9, 2014

    sir please tell me led name

  • Deepak Sharma
    August 3, 2014

    Hi sir,

    I am trying to make this lamp. Please tell me which led type can i use for this circuit.

  • AbdulBasith
    July 30, 2014

    How is the output volts ?
    &
    ‘m using 25 leds ????? How its ?

  • DHAMODHARAN
    June 22, 2014

    respected sir i want to make a led emergency lamp. i would like to glow 50 led’s so how much of rechargeable battery i use and Wat are the components need to make a lamp

  • Tarun
    June 12, 2014

    hello,
    I want to know something about this led lamp.
    sir,
    what is the use of zener diode in this lamp?

  • Sanjay Suman
    June 10, 2014

    Hi,
    I made the 2 nos. 5w LED bulb circuit as suggested by you. It worked well for some time, then one of the bulb went off. I found the both the Resistor 120 ohm was appearing burnt n black. When checked one was not showing continuity. I replaced with a new one. It start working but after few hours again it went off. I checked both the 120 ohm resistor, but it is showing continuity. What is wrong now. Pl advice how to check the circuit. The other one is still working. Also,after power off 4 led is faintly glowing contineously.

    • Seetharaman
      June 11, 2014

      Hello Suman Check the 0.47uF 400 volt and C2 for a short. If they are OK 120 ohms 1/2 watt should not change in colour. You can check your LEDs by using 3 volts Lithium disc battery CR2032 with each LED.

  • June 1, 2014

    hi.. i made transformerless powersupply to turn on 4led in seri with c 534j 400v, 470ohm, dioda bridge 1a and elco 470uf 35v. but why my led was dead?

    • Seetharaman
      June 2, 2014

      Please check the LEDs with DC and find out whether they are healthy. May be your LEDs are rated for 20mA, if so you have to use 274 400 volt capacitor. with 534J you would have passed 50mA hence they would have blown. Check for black spot in the LED through magnifying lens, if there means your leds are blown.

  • TASNIM
    April 2, 2014

    can i use 9 to 10 led on this circuit.

    • Seetharaman
      April 3, 2014

      yes. you can use up to ten leds 3volt 50ma type. but ensure that you raise the zener voltage to 33volt 1watt type.

  • Debkumar Pramanick
    February 21, 2014

    Thank u very much for sharing this … i modified it for 8 smd led 3528 … thank u again ^_^

  • C.krishnamoorthy
    January 13, 2014

    Very usful for it

  • Vishakha Varshney
    January 12, 2014

    Hello Sir,
    In this ckt I’m using 14 led’s so plz tell me that the coming changes the ckt

    • Seetharaman
      January 13, 2014

      Increase working voltage of C2 to 63 volts and raise zener diode voltage to 48 volt (use 2nos 24 volts 1 watt zener diodes in series). put a link in-place of R2. no other modifications are required.

  • sunil -sri lanka
    November 26, 2013

    I assembled the circuit is operated well, there two problems,
    1. after power off 4 led have glowed faintly , replaced 21v zener but problem did not solved
    2. Very high Temperature on R2 & R3
    Please give solutions for above

    • sunil -sri lanka
      November 27, 2013

      sunil -sri lanka
      Your comment is awaiting moderation.
      November 26, 2013 at 9:26 pm

      I assembled the circuit is operated well, there two problems,
      1. after power off 4 led have glowed faintly , replaced 21v zener but problem did not solved
      2. Very high Temperature on R2 & R3
      Please give solutions for above
      Reply

    • Seetharaman
      November 28, 2013

      Hi Sunil it is due to residual charge in 1uF. you can reduce the value of R1 to 100 K it will vanish fast. but this is not going to bother us during operation. R2 and R3 are protective resistances you can use 1 watt to reduce the heat generated. but it is a sacrificial resistance in the event of any high input surge voltage it will burn to protect the other electronics including LEDs. (a slow blow fuse)

  • John Dooley
    November 25, 2013

    Nice little experimental project – but.
    Have you measured the power consumed vs the light(lumens)output of this circuit? Could very well be that it is not as efficient as a CFL. Using resisters a capacitor acting as a resister and a shunt regulator (partial short) to drop the line voltage wastes energy as each of these components are consuming power.
    The new CFL’s use more efficient switching power supplies to provide the correct voltage for the gas tube, unfortunately this voltage is too high for LED’s , maybe a mod to a CFL power supply is possible, that could be a good project too.

  • Munna
    November 16, 2013

    hi Mr. Seetharaman,

    i’d like to use 8 LED & would be obliged if you kindly inform what is required to be changed in this circuit.

    thanks & regards.

    munna

  • krishna
    September 29, 2013

    hello Sir, i’m in need of a power supply circuit, which can drive a series of five LED’s of five mm, in parallel of six rows, hope you will guide me in this regard at the earliest, thank you sir.

  • vivek
    September 24, 2013

    dear sir tell me how many consumption from full day.

  • August 22, 2013

    thanks for the circuit, but if you use a resistor in series of LEDs, you have better performance and current will be more adjustable. you should just increase the voltage (20 volt is enough) and then 20-16=4volt divided by 50mA equals 80 ohm resistor above .5 watt.

  • kiran kumar
    July 18, 2013

    Dear sir i want to increase current from 50mA to 100mA with constant 15v which component i want to replace.?

  • Mukul
    June 28, 2013

    Hi..
    i want to ask that..
    can we…join the LED’s in parallel instead of series combination….??????

    plz. Reply to me

    • August 24, 2013

      couse the voltage is more than one LED, you must use series of LED, and one more thing :d, parallel led contolling of current for each led is a little difficut

  • Rizwan
    June 27, 2013

    Dear Mr. Seetharaman,

    I have made the above circuit using

    5 LEDs 3volts 30ma
    0.47uf 400v capacitor
    R1 & R2 100 ohms 1/2w
    C2 47uf 50v
    Zener 20 volts 1w

    Voltage across LEDs is 15v and consuming 30ma

    I have placed the LEDs on heat sink plate and want to increase the voltage and current so LEDs consume 3.4 volts 50ma.

    I tried changing C1 to 1uf but no difference

    Please advise What changes are required?

    • Rizwan
      June 27, 2013

      Sorry with C1 1uf voltage across LEDs becomes 16v consuming 60ma. My objective is to drive LEDs @ 3.5v x 5 = 17.5v or 18v approx.

      Do I have to increase C1 and any needs to change the values of C2 or R2 & R3 ?

    • Seetharaman
      June 27, 2013

      Hi Rizwan check your zener it looks it is 15 volt 1 watt. Temporatily disconnect zener and try, it should raise to 50mA with 0.68uF 400 volt capacitor. no need to change any component except 0.47uF.

  • pranav
    June 18, 2013

    sir i tried the circuit but only one led glows on touching by tester.
    plz rectify the problem.
    is it the led or the capacitor or the zener diode.
    i have used 6 led’s.all the components are same as mentioned by you above.

    • Seetharaman
      June 20, 2013

      Hi Pranav your circuit is not complete check carefully the polarity of the diodes. If with the tester is the circuit is getting completed and the LED is glowing dimly, check the whole circuit for mistakes inter connecting wiring, polarity of zener etc .

  • abhishek
    May 29, 2013

    thank you very much……the circuit is working good.

  • Samir
    May 29, 2013

    Sir, leds doesn’t glow enough. Help me pls. what should i do…..??????????

  • Rizwan
    May 23, 2013

    Dear Mr. Seetharam,

    I want to drive 24 LED 50ma from this circuit. Your reply to Prasu dated 27Feb2012 http://www.circuitstoday.com/led-lamp-from-scrap#comment-80424 says

    29LEDs in series it will be equivallent to 20w cfl use 47uF 100volt use 120volt zener and raise 0.47uF to 0.68uF.

    Since I am using 24 LED so I used 82volts zener. The voltage across zener is around 46 volts. I increased the 47uf100volt to 10uf450v from old CFL but the zener got fried.

    One more design of yours shows 10uf160volts and 1uf 400v poly and the resistances are also different i.e 100 ohms

    Kindly suggest the best configuration for 24 bright LEDs 50ma

    • Rizwan
      May 23, 2013

      Sorry my mistake I overlooked the voltage on 0.68uf. its 250v. Will buy a 0.68uf 400volt and try again.

      I also want to know which is better across LEDs. 47uf or 10uf. What would be the difference in effect.

      Also suggest the best configuration for 24 bright LEDs 50ma

  • Rohit Jha
    May 6, 2013

    Sir ,

    I am sorry forgot previous comment I am using this circuit to glow 10 Led. In this i want to replace Transformer because it become very hot AND IT takes more space So can you tell me How to replace transformer
    Please send me solution

  • Rohit Jha
    May 6, 2013

    Sir ,
    I am using this circuit to glow 10 Led. In this i want to replace Transformer because it become very hot AND IT takes more space So can you tell me How to replace transformer
    Link:-http://sdrv.ms/16c7ipc
    Please send me solution
    Thanks

    • Rohit Jha
      May 6, 2013

      I Have Forgotten to add switch before battery to turn off leds

  • Hrigwad Jha
    May 4, 2013

    Sir,
    Can i use a regulator instead of zener diodes because it is not available
    Thanks

  • rohit jha
    May 3, 2013

    sir,
    what is output voltage can i add regulator of 5 volt to charge a battery so when there is no power it will glow

  • Chandana
    April 23, 2013

    Dear Sir,

    Please tell me the changes necessary to drive a 10W/12V hi-power LED with this circuit.

    Thanks!

  • Chandana
    April 23, 2013

    Dear Sir,

    If I want to drive a 32V 9W COB LED what changes do I have to do in this circuit?

    Thanks in advance!

  • Kuntal
    April 18, 2013

    Sir i search .47 uf polyester bt i can not find it.
    Can i use .47 uf paper capcitor. Plz reply

    • Seetharaman
      April 18, 2013

      Yes Kuntal you can use ensure the working voltage specified is 400Volts or more

  • purnachandra rao.s
    March 26, 2013

    this most useful circuit now a days the electrical goods prices are hiked an very high these type of arrangements may give some use full who can use this. it’s simple to make the person who is having basic knowledge about components and electronics.
    its good and most use full, cast efective too power saver.

  • sweetha sheethal
    March 14, 2013

    hello sir ,can u just explain about the working of thus circuit .

    • Seetharaman
      March 30, 2013

      Hi Sweetha The capacitors AC resistance (reactance at 50Hz is used for reducing input voltage to the required level for the LEDs instead of a transformer to step down the voltage. further as the capacitor voltage lags the current by 90deg the power dissipated across it is zero, hence the actual LED consumption can be taken as the power of this LED lamp. Input series resistances are for reducing the inrush current. C2 to smooth the ripple DC. Zener to protect the LEDs against surges in the line.

  • shams
    February 22, 2013

    Sir, I used this ckt with 6 LEDs it is working, But R2 & R3 become very hot,
    How can I make temperature within limit. Sir pls help me. Waiting for your reply.

    • Seetharaman
      March 30, 2013

      Hi Shams increase zener diode voltage to 21volts.

  • Prasad
    February 20, 2013

    Hi Seetharaman Sir,
    Your circuit water level indicator using 555 timer is of great help from 2 months. Thanks for it.

    I am here for guiding me to build an electric gas lighter circuit using one 2A battery or one 3A battery or 2 2A or 2 3A battery. Please guide me and post necessary details with cicuit

  • Partha
    December 18, 2012

    Sir, i used this ckt with 6 leds 5mm, it seems they doesn’t glow enough as it should be. How can i make them glow to its limit. Can i use something else in place of polyester capacitor, sir pls help me out. Waiting for your reply.
    Sir u can mail me at partha_h@hotmail.com

  • Partha
    December 18, 2012

    Sir, i used this ckt with 6 leds 5mm, it seems they doesn’t glow enough as it should be. How can i make them glow to its limit. Can i use something else in place of polyester capacitor, sir pls help me out. Waiting for your reply

  • Partha
    December 18, 2012

    Sir, i used the same ckt for 6 led (5mm) in series, but the leds doesn’t glow enough. Help me pls. Can i use something in place of the polyester capacitor? Sir pls help me.

  • Biju
    November 20, 2012

    Dear Sir,
    I have made a 44 LEDs,3.6V, 20mA (two rows of 22LEDs) Circuit using same R1 & C1 values, input to the bridge measures 125V ac.But the output of C2(33micro, 160V) is zero though i have connected a 68V zener in reverse across it, what could be wrong? Please help

  • Hassan
    October 3, 2012

    Hello sir, i have made led bulb but i change the resistor and capacitor values. The problem is that when i turn off the led bulb the led are still glowing with light current store in C2.

    I do not used R2. in my case R1 is 470kohm 1/4W, R3 is 33ohm 1/4W, C1 1uF 400V, C2 250v 1uF, and after C2 is connect two resistor of 120ohm 1/2W on Positive side.

    How i solve that problem thank you.

    • Seetharaman
      October 5, 2012

      Hi Hassan it will glow for somme time and go off. it is normal. if you want, can reduce R1 to 100K to reduce this glow time. if you reduce it further it may feed more current to LEDs during operation.

      • karan
        August 3, 2013

        Sir,
        i m 3rd yr extc engnr student…i want one simple DIGITAL nd one ANALOG mini project…it shuld b using opamp or ic 555 or microcntrolr or microprocesr….plz help d needful..thank you

  • Abhishek Srivastava
    September 15, 2012

    Dear Sir,
    A simple query is about the power consumption of this circuit and also want to confirm will it work OK if kept ON for more than 18 hours continuously daily because I want to use it in place of CFL lamps.

    • Seetharaman
      October 5, 2012

      you can use permenantl in your pooja room. the power consumed will be less than 1 watt.

  • Sethumadhavan
    September 14, 2012

    Dear Mr.Seetharaman,

    Can you please provide a circuit for AC operated LED reading light with whith bright LED (bigger ones)Single or three alterable?

  • Prof S G Kamath
    September 1, 2012

    Hi,

    I am impressed. Also saw similar by Nick Vera at http://www.tehhouse.us/electrical/cfledlamp1/index.php He has shown 7 LEDs in picutres but circuit describes 5 or 10 LEDs. Your picture shows 6 but you have shown 5 in the circuit. Will it be ok for 6 LEDs or we have to increase the Zenner to 18 Volts?

    Regards,

    Prof S G Kamath

    • Seetharaman
      October 5, 2012

      Yes Prof Kamath you can use upto 10 LEDs by replacing with suitable zener( no of LEDs X 3 volt + 1 volt can be zener voltage).

  • sudeep nambeesan
    July 14, 2012

    namaste
    if this works on inverter

    • Seetharaman
      October 5, 2012

      yes it will work safely on inverter also (sine / square)

  • gourav
    June 26, 2012

    thanx sir.. gr8 project bt sir i hav a 25w cfl which is sufficnt for lighten my room…i wana knw changes in the values of components for 25w nd no.s of leds i cn use… thankew

  • Seetharaman
    June 22, 2012

    Hi PRKASH If capacitor and battery are damaged it is likely LEDs are also damaged. check with 2 pentorch cells in series each led and confirm that they are healthy. If they are healthy use the above circuit delete zener diode, increase C2 voltage rating to 350volts and reduce the value to 10uF. It should be OK.
    Hi Biyani seethasub@hotmail.com

  • Surendra Biyani
    June 22, 2012

    Dear Seetharaman Sir,

    Please advise how can I make a 30 lumen output LED set. I have an air-tight enclosure and hence using 5 LED placed within an aluminium reflector to act
    as a heat-sink. My input voltage is 6 volts DC that tapers off to about 4.5
    volts while in continuous use for about 5 hours.I need to work 10 hours
    continuously. Please do advise 1. Type of LED for long life use
    2. The Individual Resistance
    3. The zener value for reducing the amps
    4. Your E-mail ID please and your address
    Thank you ,Sir, please do reply. skb

  • June 13, 2012

    Yes,I have assembled this project ” LED LAMP FROM SCRAP ” after dismentling a useless CFL lamp and is working satisfactorily without any trouble contineously on 13th June,12. I have used 18 volts zener instead of 16V due to non availability in the local market. I have used high power LEDs.
    Many Many thanks to your and your team leaders.

  • prkash
    June 10, 2012

    Ihave ORKIA make 56 led emergency lamp which is not working when checked up the capacitor blown when i replaced the batteries or down totally insteady of replacing batteries which are are china type i thought of converting entire ckt to stamdard direct 220v regular lamp withought batteries . can I have circuit for the same with component values.

  • Seetharaman
    March 30, 2012

    Hi Raju contact me through my email and give your location in india.

  • raju
    March 30, 2012

    please assemble 1 circuit and send it to me, is it possible to you

  • March 12, 2012

    Sir I want to c.f.l scrab plz contact me

  • Amriz Khan
    March 12, 2012

    nice & Thanks for explaining it hope i learn more

  • Seetharaman
    February 27, 2012

    Hi Prasu if you use 3.2volt 50mA hi bright LEDs you can connect upto 100LEDs inseries by linking the 1uF capacitor. and raising 47uF 350volts. With the above circuit you can connect upto maximum 16LEDs. with 47uF 63volts and zener voltage as 56volt. If you use 29LEDs inseries it will be equivallent to 20w cfl use 47uF 100volt use 120volt zener and raise 0.47uF to 0.68uF.

  • Prasu
    February 26, 2012

    Which LED is used for this circuit.
    I need to do this circuit with high brightness, almost giving brightness of 20W CFL tube covering entire room.
    Necessary changes in circuit for High brightness and what might be its life span.

  • Prasu
    February 26, 2012

    Hi how many LEDS can be used. I need to design which consists of more lEDS, more brightness, less power consumption and long life span. Plz suggest.

  • Seetharaman
    February 26, 2012

    Hi Philip it will work.

  • Philip
    February 25, 2012

    Hi sir. Does this LED lamp circuit works with an AC dimmer?

  • jagadeesh
    February 24, 2012

    sir in LED light glow less than 5 means to sound the buzzer .how will i connect the circuit in buzzer

  • Pappu
    January 10, 2012

    My supply is 220V, 50Hz.I want to increase no of LEDs and the intensity
    of light.So what changes to be made? plz reply!

  • Ghulam Muhammad Toqeer
    January 8, 2012

    may i use led which we in emergency light of 4v?

  • December 22, 2011

    thank u soo much sir…..

  • Seetharaman
    December 20, 2011

    Hi Akash with 85 hi bright LEDs it will consume around 10watts.

  • December 20, 2011

    thank u soo much sir 4 giving me this precious reply sir and just ask another thing that how much watt it will take…?

  • seetharaman
    December 14, 2011

    Hi Akash you can use the same circuit change 0.47uF 400 volt to 2uF 400volts, change filter capacitor 47uF 25volt to 22uF 350volt DC. remove zener diode replace with 270 volt VDR (actually not needed)

  • December 13, 2011

    Hi sir…. Thanks for this great circuit….. I have made it and it works properly, now i want to make a high brght light with this circuit… So plz tell me that can we use almost 85 leds with this circuit??

  • P
    December 13, 2011

    hello sir how mosquito repeller works?????????/

  • Meera
    December 13, 2011

    How IC cd4047 work as multi vibrator???????????

  • Jawed Akbar
    November 30, 2011

    pcb layout of power supply required

  • Jawed Akbar
    November 30, 2011

    diagram with circuits required of veriable power supply
    thanks and best regards

  • seetharaman
    November 18, 2011

    Hi Vijay now you are getting switching power supply 12volts which is quite compact in size (1.5″ x 1″ X 1/2 “)and can cater 3 nos 1 watt LEDs in series (use 3.9 ohms 1watt in series). The price is around INR60/- only.

  • vijay
    November 17, 2011

    Resp. Sir,
    Thank you for your circuits.
    But now a days in market we are getting High power 1 watt LEDs, which requires 3.5 volts & 350 milliAmp. current.
    So I want to know the circuit based on IC & transistor for driving 1 LED. 3 LED & 9 LEDs.
    Please suggest economical circuits.

  • harsh
    November 8, 2011

    u r gr8 sir thanx v.much bt sir a block diagram is also askd by our teacher . hw cn i make a block diagram of it ?? cn u help pls?

  • seetharaman
    November 8, 2011

    Hi Harsh a night light / passage light etc of very low power consumption of less than 1 watt and with a very very long life comparing to any type of lamp as well the illumination.

  • HARSH
    November 8, 2011

    what is the result of this project? kindly reply fast

  • seetharaman
    November 5, 2011

    Hi Harsh you can use up to 12nos of 25mA LEDs with the above circuit. 4 to you will not notice much of a difference in brightness. A 25mA LED can function from 15 to 30mA with very little difference noticeable in the brightness.

  • harsh
    November 5, 2011

    thnx sir 4 ur response bt 4 leds or 6 leds.cn u clarify n sir plsa detailed answer is needed if possible .

  • seetharaman
    October 29, 2011

    Hi Harsh in the defunct bulb 1N4007 4nos and 10uF 400V capacitor are available it can be used. C1 is taking care of dropping the voltage. R2 & R3 are input surge current limitters. C2 is the filter capacitor to avoid flickering of LEDs. Zener is for protecting LEDs against peak surge voltages. the capacitors and the resistances are calculated with the standard formule. V= IR and f = 1 / (2 pi X R X C).

  • harsh
    October 28, 2011

    hi sir… ur project is damn good bt cn u pls help me by giving brief description of project ,theory related to the project ,working /operation of project ,block diagram ,result of project ,cost of project , datasheet for each components .sir cn u pls give above mentioned details asap….
    hoping 4 favorable response .

  • Seetharaman
    September 12, 2011

    Hi Rambabu yes with 10% tolerance you will have problem.
    Hi Nitin you can use two LEDs inseries and three of these in parallel to the 6 volt supply. Current limitting resistances are not required. if your led samples are between 3.2 to 3.6 volts use each LED in series with 56ohms to he supply.

  • September 11, 2011

    Hi Seetharaman Sir, an you help me. I want to use 6V 500ma SMPS power supply to light 6LED’s. How can I do this I want to make this urgently ASAP. Please reply.

  • pavan
    September 10, 2011

    hi,it is always good to have spike protector (mov) in place to protect the circuit from surges. increasing the value of filtering capacitor value can result in smooth operation .
    better to have a current limiting resistor after regulator part in series with leds.

  • rambabu potluri
    September 9, 2011

    sir due to tolerance in zenerdiode and leds, the zener diode 18 v is prefered device

  • seetharaman
    August 3, 2011

    Hi Jagan for 1amp the capacitor has to be 14uF 400 volt polyester not electrolytic. will be difficult to get with 7nos of 2.2uF 400 volts polyester it will be expensive and bulky. hence you can use switch mode supply will be efficient compact and economical.

  • jagan
    July 31, 2011

    Hi Seetharaman,

    LED lighting is my hobby. I tried your circuit it works fine. I want to know if the circuit can be modified to draw 12V -1 Amp form this circuit. with regards

  • Seetharaman
    June 4, 2011

    Hi HTOO please calculate the Xc for the capacitor at 50Hz, now add up 2 nos 120 ohms to that each LED is say 3.2 / 0.05A 64ohms add up every thing and use this as a divisor, calculate the current through the LEDs.

  • Htoo Naung Oo
    June 3, 2011

    Hi Seetharaman, i’m electrical student. I took this circuit for my project. So that, may i know how to calculate this circuit because i can’t solve. thzzzz

  • Seetharaman
    April 30, 2011

    Hi Binoy check your mail for my reply. You have to be very careful in choosing the LEDs. use the light for ten minutes disconnect feel the LED temperature if they are quite warm you are driving with higher current reduce capacitor value.

  • Benoy
    April 29, 2011

    Dear Sir,
    i created the circuit in 4 Common pcb’s with 4, 5 & 6 LED’s …. but the problem in all models is the circuit lights up clearly for 3 – 4 hours …. then it become fade…. i changed the components many time including the 1N4007 diodes with several makes…. The same 1N4007 functions in the 24 LED circuit(http://www.circuitstoday.com/mains-operated-led-circuit#comment-31282) clearly….
    please explain the possible reasons…. shall i change the 1N4007 to 1A,400V Bridge?

  • Seetharaman
    April 25, 2011

    Hi Robin For 4 LEDs of 50mA. All are same except Zenar reduce it to 13volts 1 watt.

  • Seetharaman
    April 25, 2011

    Hi Rohit Around 210 volts with the specified LEDs.

  • rohit
    April 24, 2011

    Hi Seetharaman,
    What is the voltage drop at the polyester capacitor junction.

  • Seetharaman
    April 21, 2011

    Hi Keralayahu you are correct in the first prototype i have used 100 ohms and latter models i changed to 120 ohms to just limit the surge current to just 1 amp.

  • keralayahu
    April 20, 2011

    Dear sir,
    In your prototype snaps there displays a Brown -Black-Brown resistor, but id doesn’t mentioned in the circuit….

    http://www.circuitstoday.com/led-lamp-from-scrap/pcb-closeup

  • robin
    April 16, 2011

    Dear Seetharaman sir,
    I am herewith a FOUR holed CFL adaptapor, please lead me the capacitor n Resistor values with the 4 x 50mA LED’s

    Thanks a load n advance

  • Seetharaman
    April 11, 2011

    Hi Herman you can use the output 4 leads to light up 11watts 4 pin PL lamp. I have used 18 watt CFL lamp circuit with 11watts PL and it is still working fine. You can swap this other defective CFL where tube is good but electronics have failed.

  • Herman
    April 11, 2011

    Hi Seetharaman,
    I have a broken CFL, then I take out the electronic ballast (still in good condition). Can I use that electronic ballast to energize LED? Because I see in those schematic DC power supply and other side AC power supply. How can I possible to get safety DC power supply from that things to light on LED? I just want to try recycling that CFL. Thank you.

  • Seetharaman
    April 6, 2011

    Hi Soji Disconnect LEDs check the voltage across the Zener it should be around zener’s voltage. if not check D1 to D4 some batch has given us problem as the they were having low PIV of only 50 to 60 volts. ensure that you are using a good company 1N4007. otherwise you should face any problem.

  • Soji Varghese
    April 5, 2011

    Hi Seetharaman sir, i made the circuit in a conmmon PCB, but the problem is the 50mA (4 leg LED’s, 6 LED’s) with sometimes the Polyster capacitor’s output voltage doesn’t come n if i changed the polarity of the AC it clears but the LED doesn’t lights up. I used the 20volt ZENER. I connected the right way like the displayed diagram, please help…. how can i check the whole circuit with the voltages in every pin… and how can i understand if the electrolytic capacitor is properly working or not…. expecting the reply @ the earliest… Thanks in advance

  • Seetharaman
    March 18, 2011

    Hi Sony the maximum current you get from this circuit from 230Volt 50 Hz is only 50mA even if you shot the output. Hence you can use maximum 2 chains of 25mA LEDs in parallel.

  • Sony Bagus
    March 17, 2011

    Hi SEETHARAMAN Sir, i am newbie in electronic, but i am interesting in LED project. I want to ask about your LED lamp circuit, if I add an IC regulator 7812 (this power output is 12 Watts), and I use 10 LED (white super bright each 4.5 Volts DC, 25 mA). I install the LED configuration on parallel with resistor 150 Ohm each LED, can I do that ? Thanks for your answer.

  • Kenny
    March 16, 2011

    Hi This is what i am looking for but must have various coloured LED’s slowly changing colours for the garden.

  • Seetharaman
    March 16, 2011
  • SISON.C.S
    March 16, 2011

    dear seetharaman thank you very much for your brilliant idea.most of such circuit available in the market are without zener diode so it canot be used prolong.Every spike damage leds onebyone.In your circuit led will never damage due to spike.thanks alot.let me know your email id please

  • Seetharaman
    March 13, 2011

    Hi Sabitha thanks for pointing. you can use 6 LEDs. The circuit is for 4 stem (2 U tubes)light you can use 5 LEDs with that. latter i switched to 6 stem (4 U Tube)light, which is popular now, hence 6 LEDs are used. you just add one more LED in series and increase Zener diode to 20volts. If you are going to use standard 5mm 25mA LEDs 6nos please reduce the capacitor value to 0.33uF no other changes are required.

  • Sabitha Joshi T
    March 12, 2011

    Hi SEETHARAMAN sir, i am a newbie in electronics as i am a 1st year diploma student in Polytech. I was in study with LED lighting, and i got your projects in this site. kindly clarify me the above circuit shows 5 LED’s and in the prototype you made shows 6 LED’s… am interesting and collectd the components. Please clarify me the number of LED’s can i use… please send me ur e-mail address too….

    Thanks in advance

  • Seetharaman
    March 10, 2011

    Hi Trike If you are getting only 25mA round LEDs then reduce capacitor value to 0.82uF or two nos 0.4uF in parallel.

  • Seetharaman
    March 10, 2011

    Hi Trike sorry, in future this will be taken care.
    the following 4 changes are required in the above circuit for 110 volt 60Hz operation.
    C1 1.5uF 250V, R1 220K 1/4W, R2 & R3 56 ohms 1/4W other components remain the same.
    The approximate power consumption is less than 1 Watt, around 1 unit per month.

  • Trike
    March 9, 2011

    A lot of these 230 volt circuits look interesting, but I for one would like to see perhaps a note on converting the input to 110V AC input for American use as well, or an article on converting inputs so that we could adapt these circuits correctly and safely for our own use.

    • Chinmoy Mitra
      May 18, 2015

      Hi Trike,
      It is ridiculously simple to convert this circuit for 110V application. Just halve the input series capacitor to 0.22 uF, rest need not change. Try it and let us know the results!
      Regards

  • brontay
    March 9, 2011

    Tell me please how many units are consumed by this circuit in 1 hour?

    • nitin
      January 25, 2013

      hi sir can you tell me a minor project of branch electronic and communication for diploma which required minimum 3 ic’s and 13 component

      • nitin
        January 25, 2013

        sir pls tell me fast

        • July 7, 2013

          sir, i would like to ask, what is the output voltage without the zener diode in this circuit?

          • Seetharaman
            July 9, 2013

            Hi Irwin without LEDs connected it will be zener voltage once connected to rated LEDs it will be 15volts

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