Mains operated LED night lamp

john February 17, 2009 53 Comments

Description.

Here is a simple and powerful LED based night lamp circuit that can be operated directly from the 230V mains supply. The are total 24 white LEDs used and the lamp produces an output of around 15W.The resistance R1 and capacitor C1 provides necessary current limiting. The circuit is sufficiently immune against voltage spikes and surges.

Circuit diagram with  Parts list.

mains-operated-led-night-lamp

Notes.

  • Assemble the circuit on a general purpose PCB.
  • The capacitor C1 can be polyester type.
  • White LEDs are preferred in this circuit.
Comments
  • P PAVAN KUMAR
    November 24, 2013

    I want to do an experiment with more than 200 led’s how can i connect these led’s on 1 phase supply.
    Please give me an idea…..

  • Bruno Salas
    July 12, 2013

    Mr. Seetharaman. What is the value of C1 if I live in a country with 120VAC and 60Hz?

  • ranjit
    February 1, 2013

    can any tell me which led required for this design ac or dc led

  • Karthik
    January 18, 2013

    hi, i want to make 33no of 5mm led 20ma output with 220v ac ps. so what are the components required?

  • sireesha
    September 11, 2012

    please add the operation of the ckt

  • anurudda999
    August 22, 2012

    hi i cannot find 0.22uF 1000v all i can find is 0.22uF 100v what can i do and my R1 is 1k 1/4W what can i do please help me thankyou

  • jeh cabacungan
    June 26, 2012

    Thank you Seetharaman, will give you update once I finish the project. Thanks for the support….Jeh

  • Seetharaman
    June 25, 2012

    Hi Jeh For C1 use 0.33uF and R1 1.5K 3 watts

  • jeh cabacungan
    June 25, 2012

    Hello Seetharaman, given the rating of the LED, for 6 pcs; 3 pairs back-to-back, what would be the value of the capacitor and the resistor?
    Thank you , Jeh

  • Seetharaman
    June 21, 2012

    Hi Jay may be your capacitor is faulty. connect 0.25 in series with one pair of LED back to back and with 1k 1 watt also inseries and try for the glow. if nothing happens and if the LEDs glow OK. then the fault is that the LEDs are rated for 3.2volt 15mA.

  • Jeh
    June 19, 2012

    Hello Seetharaman, What could be the cause why all the LEDs got busted? It was working for some 15 seconds but it did not glow anymore after I have switched it off then on again.
    Thank you, Jeh

  • Jeh
    June 18, 2012

    Hello Seetharaman, I have checked the LEDs with lithium cell. Unfortunately, all 6 LEDs are dead. Yes, I have actually used two capacitors (0.25 & 0.1uF) both at 630v in parallel. I hope that the voltage is not too much if its in parallel? I am not sure if the caps are still working after the test that I have made….Jeh

  • Seetharaman
    June 17, 2012

    Hi Jeh one of yur LED might have blown. With a magnifying glass look into LED if any block spot is seen it is blown. you can check each LED’s glow by using a lithium 3 volt disc cell-faster method. Is your 0.35uF rated for 400 volt.

  • Jeh
    June 16, 2012

    Hello Seetharaman, I was able to assemble the project. Fortunately it was working when I plugged it for 15seconds however, when I switched it off then turned it on after some seconds the LEDs did not glow anymore till now. What do you think is the error? I have used 0.35uF Capacitor and 220ohms 1 watt resistor. There is no sign of burn or any part that gets hot. Thank you, Jeh

  • Jeh
    June 10, 2012

    Thank you Seetharaman for the support. More power to you and Congratulations again for a job-well-done.
    Jeh

  • Seetharaman
    June 10, 2012

    Hi Jeh it will be 5mm 3volt @ 20mA variety. So my earlier comment of 8th june is ok for your application. Normally 7.5mm will come as jewel lamp with 2 leads for panel indication use. please donot worry about it. You go ahead thinking as 5mm ( some makes are around 5.5mm with 2 leads one little longer, indicating anode)

  • Jeh
    June 9, 2012

    Dear Seetharman,I was the one who measured it actually and it is more than 5mm but less than 10mm. The store told me that it is 3volts. It has two leg terminals, cylindrical with almost flat top part. It looks the same as the 3mm size LED. Well, I just dont know if it falls to the 5mm size category. I can send you a photo to your email if you could send me yours.
    Thanks, Jeh

  • Seetharaman
    June 9, 2012

    Hi Jeh as per the voltage and current requirement of the LEDs the values of C1 and R1 will change. Send me the details of your 7.5mm LED, it is not a standard size. (normally freely available in the market sizes are 3,5,10 mm)

  • Jeh
    June 8, 2012

    Hello Seetharaman,I am sorry I should have said 3volts 7.5mm diameter instead of 3mm LED. Will the values change?
    Thanks Jeh

  • Seetharaman
    June 8, 2012

    Hi Jeh 3 volt 3mm white LEDs will consume 20mA at 3.6 volts. 3Pairs back to back. Increase C1 to 0.33uF. no other modifications are required. The power consumption will be around 3/4 watts for the modified circuit. By reducing R1 to 220 ohms your consumption will be less than 0.4watts.

  • Jeh
    June 8, 2012

    Hello Seetharaman,using the same circuit but using only 6pcs 3volts 3mm diameter LEDs, can you help me if what values of capacitor and resistor should I use? I was able to complete the first project but the store run out of LED.

    Thank you again, Jeh

  • Jeh
    May 28, 2012

    Hello Seetharaman, Thank you for the unselfish reply. More power to you…Jeh from Philippines

  • Seetharaman
    May 28, 2012

    Hi Jeh first LEDs anode to the second LEDs cathode and vice versa first LEDs cathode to second LEDs anode etc. as shown in the above circuit diagram.
    with 0.1uF you can connect 1 pair of LEDs back to back and use the illumination will be quite low as only 7mA wll be flowing through the LEDs.
    with .033uF a pasir of LEDs will get less than 2.5mA hence you will have only a faint glow.
    the charge available in the capacitor is getting completed through the leakage path in your holder circuit and you will have faint glow for a long time. then it will become dark. to avoid this problem add a 100K 1/4 resistance in parallel with C1 which will discharge the capacitor fast hence the glow LEDs will fade away fast.

  • Jeh
    May 27, 2012

    Thanks Seetharaman for the reply. Just a small clarification, when you say back to back you mean I will connect the two LEDs with one +leg of 1 LED to the -leg of the other LED and vice-versa?
    If I would like to use just one 0.1uf cap, how many LEDs and value of resistor should I use? likewise with 0.033uF capacitor?
    By the way the circuit is a great one! Congratulations for that! I just dont know if it is normal that when I switch it off some LEDs are a bit glowing and they don’t go off unless I remove totally the unit from the mains…Maybe you could help me again to solve this observations…
    Thank you so much, Jeh

  • Seetharaman
    May 27, 2012

    Hi Jeh for 50LEDs you can use 25nos back to back. You have to reduce R1 to 220 ohms 1 watt and increase the capacitor to 0.433 uF. That is 0.1 4nos in parallel with 1no 0.033uF.

  • Jeh
    May 27, 2012

    Hello Seetharaman, I have 0.1uf/630v and 0.033uf/630v capacitors available in the market. Can you help me if how many LEDs are required for each capacitors? I wanted to increase the nos of LEDs to 50.
    Thank you, Jeh

  • ramil
    May 8, 2012

    hi

    can you provide me a detailed diagram for 50 leds/ 60 leds / 80 leds and 100 leds as well as C1 and R1 value in 230 volts/60Hz mains supply.
    your favorable and prompt reply will be highly appreciated.

    Thank you so much..

  • Seetharaman
    April 22, 2012

    Hi Vinay with 110volt 60Hz. C1 should be increased to 0.68uF (684 / 250Volts) polyester capacitor. Reduce R1 to 220 ohms 1/2 watt. Ensure that you use 3.2 volt 25mA HIGH BRIGHT 2 PIN WHITE LEDs

  • George
    April 21, 2012

    Hi ‘

    I wonder? it must use the capacitor to the circuit.

    I also wonder? not enough resistor only? through

  • Vinay
    March 29, 2012

    Hi, great simple circuit, any body know what modifications I will have to do if I plan on using it on 110V instead of 230V

  • January 19, 2012

    This seems to be the simplest circuit I have seen so far as it does not use a rectifier.

  • Rohit
    August 13, 2011

    Hello Seetharaman,

    Thanks for the Information.

    Regards

  • seetharaman
    August 13, 2011

    Hi Rohit use 0.47uF instead of 0.22uF, use 220 ohms 1/4 watt (will do) or 1/2 watt for 1k 3Watt. The power consumption will be around 2watts.

  • Rohit
    August 12, 2011

    Hello Seetharaman,

    I propose to use about 25 nos white LED in each group amounting to 50 nos. led (3.2v 25mA). I would be using 0.22mfd 400 volts and R1 as 100ohms 1 watt. The Power consumption would be approx. 3.5 watts.

    Kindly suggest if this is okay.

    Regards

  • Jack
    August 9, 2011

    Thanks SEETHARAMAN

  • seetharaman
    August 3, 2011

    Hi Jack 7LEDs (3.2 volt 30mA white or blue LEDs) back to back as in above circuit, that is 14 LEDs in all. the capacitor should be 0.47uF and R1 should be 220 ohms 1watts

  • Jack
    August 2, 2011

    Dear Seethraman,

    I want to connect 7 leds 5mm(blue or white) what will be resistor and capacitor values. Thanks.

  • Saifur
    July 1, 2011

    thanks Seethraman

  • Seetharaman
    June 21, 2011

    Hi Saifur 2watts approximately.

  • Saifur
    June 20, 2011

    what is the power consumption of this ckt? how watt?

  • Chetan M.P
    May 14, 2011

    I assembled the above circuit bu using 1500 volt capacitor and it is working fine..
    thank you sir.

  • Seetharaman
    May 4, 2011

    Hi Bilal 3.2 volt 25mA

  • bilal
    May 3, 2011

    what is the volt rating of single led

  • Seetharaman
    April 25, 2011

    Hi Sison Connect 50LEDs back to back in series as above. Reduce R1 to 220 ohms 1 watt. change C1 to 0.47uF 400Volt. The only drawback is if you view the LEDs directly it will look like they are flashing. but illumination will be ok, you will not notice any flicker.

  • sison.c.s
    April 23, 2011

    sir,
    how can i increase the number of LEDs up to 100nos.what modification require?pls help

  • Seetharaman
    April 30, 2010

    Hi Ravinder I have assembled with 30 LEDs, it consumes less than 1.5watts, as a night light it is ok. by reducing the resistance to 220ohms 1/4 watt you can further reduce. it was giving low filickering illumination due to each LED operating for half the cycle, as there is no rectifier and filter circuit.

  • ravinder
    April 30, 2010

    Is the power consumption 15 W or is it the light output? If the circuit consumes around 2-3 watt, this would be excellent circuit for saving energy. Ravinder, Hyderabad, India.

  • April 26, 2010

    Please circle I want a real metal detector at a depth of a remote

  • VG KRISHNA
    April 8, 2010

    I assembled the above circuit. It is working excellent. I thank CIRCUITS TODAY very much for providing such a circuit. I want to analyze and understand the circuit. I measured the voltage past the capacitor and resister with a digital multimeter but no a.c.voltage is being shown. I connected a zero volt bulb also past the capacitor and Resister in the ciruit but it has not glowed. Why ?Since I am not a technical person, and for the benefit of memebers like me, I want somebody or the Designer to kindly explain how the circuit is working as to:
    1) what is the voltage past the capacitor and the resister
    2) what is the voltage of the all the LEDs put together
    3) what is current in milliamps passing thrugh the LEDs
    4) whether the capacitor and resister are considered to be
    in series or in parallel, along with the LEDs.
    5) why the glowing leds flicker even though it is not highly noticeable. Thanks in advnce. V.Gopalakrishna, Hyderabad, India.

  • dinoop thomas
    February 7, 2010

    a good site

  • Sree
    February 4, 2010

    good circuit,but doesn’t reduces the led life drastically ??

  • September 25, 2009

    I would be pleased to know if any other capacitor would work.If any luck please mail me at aravindj36@gmail.com

  • pscraja
    March 9, 2009

    What is the specification of the LED you have used in this circuit. If this information is given, it would be useful.

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