Simplest 1 Watt LED Driver Circuit at 220V/110V Mains Voltage

White LEDs are the lighting solutions of the future, simply because these devices can be lit brightly at relatively negligible power consumption. As an example, 1 watt LEDs are getting very popular nowadays due to their mini size and intense point brightness outputs, and as usual these require just  a watt at 4 volts for generating dazzling illuminations.

In this article I will show you how to build a very simply 220 V or 110 V operated 1 watt LED driver circuit,that would cost you not more 1/2 a dollar, excluding the LED of course.
I have already discussed capacitive type of power supply in a couple posts, like in LED tube light circuit and in a transformerless power supply circuit, the present circuit also utilizes the same concept for driving the proposed 1 watt LED.
In the circuit diagram we see a very simple capacitive power supply circuit for driving a 1 watt LED, which may be understood with the following points.

The 1uF/400V capacitor at the input forms the heart of the circuit and functions as the main current limiter component of the circuit. The current limiting function makes sure that the voltage applied to the LED never exceeds the required safe level.
However high voltage capacitors have one serious issue, these do not restrict or are not able to inhibit the initial switch ON mains power in rush, which can be fatal for any electronic circuit LEDs are no exceptions.
Adding a 56 Ohm resistor at the input helps to introduce some damage control measures, but still it alone cannot do the complete safeguarding of the involved electronics.
An MOV would certainly do, also what about a thermistor? Yep, a thermistor would also be a welcome proposition.
But these are relatively at the costlier side and we are discussing a cheap version for the proposed design, so we would want to exclude anything that would cross a dollar mark as far as the total cost goes.
So I thought of an innovative way of replacing an MOV with an ordinary, cheap alternative.
What is the function of an MOV? It's to sink the initial burst of high voltage/current to ground such that it is ground before reaching the LED in this case.
Wouldn't a high voltage capacitor do the same function if connected across the LED itself. Yes it would surely operate the same way as an MOV.
The figure shows the insertion of another high voltage capacitor directly across the LED,  which sucks the instantaneous influx of voltage surge during power switch ON, it does this while charging up and thus sinks almost the entire initial voltage in rush making all the doubts associated with a capacitive type of power supply distinctly clear.
The end result as shown in the figure is a clean, safe, simple and a low cost 1 watt LED driver circuit, which can be built right at home by any eletronic hobbyist and used for personal pleasures and utility.

CAUTION: THE CIRCUIT SHOWN BELOW IS NOT ISOLATED FROM THE AC MAINS, THEREFORE IS EXTREMELY DANGEROUS TO TOUCH IN POWERED POSITION. 

In the above shown simple 1 watt led driver circuit, the two 4.7uF/250
capacitors along with the 10 ohm resistors form a kind of "speed
breaker" in the circuit, this approach helps to arrest the initial
switch ON surge inrush which in turn helps to safeguard the LED from
getting damaged.

This feature can be replaced with an NTC which are popular for their surge suppressing features.

This
enhanced way of tackling the initial surge inrush problem could be by
connecting an NTC thermistor in series with the circuit or the load.


Please check out the following link for knowing how to incorporate an NTC thermister in the proposed 1 watt LED driver circuit


The above circuit can be modified in the following manner, however the light may be a little compromised.


A good way of tackling the initial surge inrush problem is by connecting an NTC thermistor in series with the circuit or the load.

Please check out the following link for knowing how to incorporate an NTC thermister in the proposed 1 watt LED driver circuit

https://homemade-circuits.com/2013/02/using-ntc-resistor-as-surge-suppressor.html

The above circuit can be modified in the following manner, however the light may be a little compromised.

370 thoughts on “Simplest 1 Watt LED Driver Circuit at 220V/110V Mains Voltage

  1. Have questions? Please feel free to post them through comments! Comments will be moderated and solved ASAP.
  2. Hi Swagatam

    Words are not enough to thank you for all your services to the community in this day and age and in this materialistic world. I appreciate every single word and sentence from you and pray for your wealth, happiness and growth.

    Regards

    Sam

    • IN 4007 diode is rated for 1000v – 1A. connecting 50 x1w leds would put 5000mA (100mA per 1W led) through the DIODE Bridge.. Pl explain how can it work?

    • series connection does not call for current multiplication, rather it involves voltage multiplication….so for 50 LEDs in series current requirement will be 100mA….but voltage requirement could be approximately 50 x 3.3 = 165V

    • hi Dear, This Faisal Mateen, I have tried to Lit up around 48 LED's of 1 Watt in series with the same circuit and it works well, BUT!!!!!!!!!!!!!!!!!
      Some Times when i Switched ON any 1 of the LEDs in Series Burst out , what can be the reason for this ? any Idea??
      Secondly The Value of Input Capacitor i used was 3.3 uf 400 Volts, and the capacitor parallel to the LED Series i used the 100 uf Polar Capacitor with 250Volts, and i did not used the 56ohms resistor because it gets very Hot even if i use 5 watts Resistor at the Input 220v Ac, kindly correct me what mistake i am doing???
      Thanks and Regards/ Faisal Mateen

    • Dear Swagtam Thank you very much for the very quick reply, one more question is that if the transistor No MJ 13005 is not available then what else number??? i can use of NPN Transistor, 2nd question is that do i must need to use a Transistor Heat Sink with it or not????
      I need to make the circuit sealed and water proof so that is why i may have some problem if i put a Heat sink with the Transistor.
      Regards/Faisal Mateen

    • You may use MJE340 in place of MJ13005.

      Heatsink is not required for the transistor, in fact nothing should become hot.

      You may immerse the whole assembled circuit in EPOXY and dry it, this will make it water proof and weather proof.

      Regards.,

    • Dear i tried after making the circuit but it is not working at all, when i checked the power output it is giving only 10 volts output, i used MJE 13005 .(this practice was for surge protected 1 watt driver circuit.
      2ndly when i tried 1watt led circuit by making it through 56 ohms 1 watt Resistence, 1 uf (105K) capacitor 400 V and 1 Meg Resistor 1/4 w. and Ready made Bridge rectifier.and at the output of rectifier i mean at + and – i use another 1uf 400 v capacitor and when i powered on with 1 watt LED it burst immediately…. :(, what should i do now????

    • Dear Faisal,

      As you can see in the respective pictures and video, I have successfully built the circuits, however the circuit presented in the above article is not reliable therefore it would be better to build the surge protector circuit only.

      You might have connected the transistor wrongly, just check everything again, the circuit has been tested by me and it works perfectly.

    • Thanks for the reply,dear i found the problem it was with the 1uf Capacitors, they were not working at all although i buy the Fresh pieces, but when i replaced with another brand circuit started working, but another issue came across was that the illumination was low , so when i checked the voltage at every LED i found 2.1 or 2.2 Volts DC thats why the illumination was not proper, as you know that 1 Watts LED's working volts are in between 3.2 to 3.6 Volts, so when i increase by adding 3.3 uf Capacitor parallel to 1uf the illumination was very good and the volts across the LED's were 3.1 VDC, but the 56 ohms resistor and the Transistor both started heating up and after some time the 10 K resistor which is connected to the Bridge + Positive line also started Burning. please let me know how can i increase the voltage across LED's to get full illumination without heat up of other parts.
      Thanks and Regards/ Faisal

  3. Hi. This is a wonderful site. Great Job. Only one question. Kindly let me know how many LEDs we can connect in series. Are there any limitations that for the circuit we can use only 3 or 4 1 watt leds. Please reply.

    Kind regards,

    VKS
    9840023846

  4. Hi. Great web site. I am learning many things from your site and trying out though I do not have an electronic back ground. Kindly let me know how many LEDs we can use for the above circuit. If we use more what are the changes needed for the same.

    Kind regards,

    VKS
    9840023846
    Chennai, India

  5. hi there Swagatam,

    in my place 1watt LED is not available.
    can i use 10mm LED for this circuit?
    is there any modification?

    hope to see your reply.

    Thanks a Lot,

  6. Hi Swagatam,

    part list of my project:

    334/600v
    105/250v
    1N4007 x 4
    56 ohms
    1M
    10MM LED

    problem – my LED wont light up and i only got 1.5Vdc in my output.

    can you help me with this?

    Thanks in advance

    • Hi,

      That cannot happen, I think the LED is not OK.

      When a 350mA 1 watt LED is able to illuminate then any other less rated LED should also easily work with this circuit.

      Check the LED or replace with some other form of LED.

      Regards.

    • Hi,

      actually my LED got busted when i turn it on.

      i only put a 12v zener diode parallel to CAP 105/250V to make it work.

      what i want is to eliminate the zener diode to work it perfectly.

      i wont light up if i series 2 LED with a zener diode. it will only work in parallel but the voltage is dropping.

      what is the best to do?

      Thanks,

    • You can put a resistor in series with the LED, may be 1 K 1 watt, or put a diode 1N4007 across the points of the bridge, where the 105 cap and 56 Ohms are connected. the cathode of the diode goes to the cap end and the anode goes to the 56 Ohm end.

      Regards.

  7. Hi,
    Love this circuit a lot. Just one question I want to connect 60 LED's of 1 watt what will be the gr8 circuit for accomplish my task at 230v ac. Thanks in advanced.

  8. dear Swagatam,
    Thanks for the reply. Just one question.
    I want to know 2uf/400v mean series 1uf/400v or parallel.

  9. Hi Swagatam,
    Considering that you are using a 1uF cap, I am unable to understand how this circuit can provide about 350mA to the 1W LED (at about 3.3 to 3,5 V)?
    The reactance for this would be around 3.18K (1/2pifC), which should put the output current at around 72mA.

    • The circuit can never provide 350mA, not even 150mA, in an attempt to supply maximum current possible which amounts to 70 to 100mA max, the circuit voltage drops to the LED fwd voltage of 3.5V and the LED finally lights up at 3.5V/70-100mAcurrent.

      The process also keeps the circuit very safe from surges.

    • Meaning that the LED would not light up at it's full brightness? Also, if you put 4-5 in series, will they be bright enough?

      On the other hand, if I have to run this of 12V (car battery), and have to put about 9 of them (3 series x 3 parallel), what would you suggest (for maximum brightness)

    • Yes that's right, yet the light is so bright that you cannot look into it even for a second.

      With a battery it's not a problem, you will get full brightness, just remember to connect a 150 Ohms 5 watt resistor with each series.

    • hey this is bhavesh patel.
      plz ans me. if i use 3.3uf at i/p side i anm getting 240ma,
      also i have connected 10 led in series each of 2.1v drop accross it, so total voltage drop should be 21v but it is showing 32v. so can u plz explain me reason.
      i have don all this experiment on simulator.

    • thanks for your quick reply…….

      and one more think

      In your earlier comments you told that your circuit will give 70 to 100mA and 3.5V if so the wattage will be only 0.35W.then how can we use it for a 3W LED

      no load voltage will be around 296V if we connect a LED then LED fails, how can we use the circuit

    • Hi thank you for your reply

      and we have tested with your circuit we used 2.2uF in input and 1uF in output me getting no load voltage as 296V only.when connecting my LED also burned.

  10. Can we use this circuit as night light i.e. continuously for more than 10 Hours, I read on web that 1W LED required heat sink to operate properly, please guide. Thanks

    • You can keep this circuit switched ON permanently without damaging anything.

      The circuit will be able to provide only 50% of light so there's no danger of heating up.

  11. Hi..Swagatam
    Your this Blog is Truly AMAZING..!!!
    On every page I find some or the other information Important..really Great Work.!!!

    Max to Max…Total how many 1Wt LEDs, we can connect to this particular circuit???
    Does it provide the same illumination as a 40Wt TubeLite, for a normal room size???
    If it doesn't then how many LED's we need to connect to get same illumination???

    Regards,

    • Thanks PP,

      I haven't tested it practically, I think 20 leds can be accommodated….. i think it won't give a 40 watt FLT equivalent light….it will need to be experimented practically, though.

      Regards.

    • Sir…
      In reply to one of you post, you have mentiined upto 60 LEDs you can connect…while doing this will the illumination redused by some percent…???

    • Hi Swagatam..

      Thanks alot…I am sure, now I am going to build this 1Wtt LED Driver.
      Is 1Wtt LED is costly..because I need to get 50 Nos.
      Just for precaution.. If we use it for extended time say for about 10Hrs daily…does any of it's part gets heated up…
      Regards,

    • Hi PP,

      Each of them would cost you around Rs.12/- if you procure the 50nos strip.

      According to me nothing would go wrong even if it was kept switched ON forever, however i wouldn't guarantee anything as I haven't kept them used them for so long.

      Regards.

    • Hello PP,

      This circuit has been designed in such a way that it will not cause any deterioration in the LEDs, however actual confirmation can be made only after practical testing.

    • Sir…
      What are POWER LEDs and How different they are form these 1Wtt or 2Wtt LEDs???
      I came accross when I was browsing Elektor Magazine and reading in book store, Sir, the same article I would like share with you…The intro of the article goes like this…Power LED Driver By Michael Hölzl (Germany)
      If you want to operate power LEDS with a truly constant current – which significantly
      prolongs the lifetime of the lamp and avoid the power loss resulting from using a constant voltage supply with a series resistor, you need a suitable constant current source. However,the only way to achieve really good efficiency is to use a switching regulator. Altogether, this means that you need a switching regulator designed to generate a constant current instead of a constant voltage.

  12. What about power factor correction, PFC. Can I put an inductor somewhere to increase the power factor and what would you recommend? The PF of this circuit is probably less thn .5.

    • I know one by itself is trivial but what if everyone had LED ltes and now there were 100s of these circuits. The PF of the LED capacitive powered circuit I bult has a pf of only .23!!! Most CFLs have about .6. It would take quite a big inductor to compensate with a freq of 50 or 60 hz. Maybe u know of a electonic inductor i could build?

      Your robot filter word is extremely difficult to read for publishing verification…

    • I'll think about the PF issue and hopefully will come up with an inductor solution and post it here.

      I did not understand what you meant by

      "Your robot filter word is extremely difficult to read for publishing verification…"

      Can you please explain it?

      Regards.

  13. Sir
    I want to connect 4 1w LEDs to my room. Can I use this circuit to connect those 4 LEDs? And how?

    If I connect 4 1w LEDs to above circuit, is that LEDs lights up their maximum bright or not?

    If it is not the maximum bright of them how can I increase light until their maximum?
    please explain me

  14. Hi Swagatam, Your efforts and blog is appreciated.
    But sorry to give you a negative feedback. As you know, the current is directly from the 230Volt mains, and charging and discharging circuit of the capacitor is perpetual, this circuit VA is about 0.35 x 230 = 80VA !!!!!!!!!!! So such power supplies should not be used more than few milliamps of applications (say 5mA).

    • Hi Bipin,

      Thanks very much. But I failed to understand a few things, what's 0.35 and what's 80 VA, are you referring to the LED power as 80VA?…. the LED used is just 1 watt rated, so I am a little confused….

  15. i hav 1wat led 350ma, plz tell me the exact R1,R2,Capacitor ?
    i can use 1mm 450v Capacitor & 57OHm R but not work led never glow & output not stable out put ratio is 1v to 2.5 v .plz tell me wat can i do ?

  16. 1 watt led not consuming 1 watt instead consuming around 15 watt by applying 70mA 3.4 v 1 watt

    Adding multiple PF increasing Brightness proportional to current consuming

    How to really save power ?

    Will a transformer could reduce power wastage?

    Please guide me how simply build a High power led Driver like China made Led driver

    • Thanks very much for your reply because I am finding a solution but Sir,

      I have measured AC ampere by my millimeter ( can show wrong result) , it is drawing around 68 mili amp current from 225v AC mains That is 15.3 watt for single LED.

      For cross verification in theory

      As per reactance rule 1/(2π•f•C) a 105k PF can only provide around 70mA AC current for 225v AC and keeps a resistance (reactance ) around 3184 ohms but no heat produced by PF unlike normal resistors dissipated excessive heat.
      LED consuming only 0.224 watt (P=E*E/R) working as a 45 ohm (R=E/I) resistor in 3.2v DC 70mA current; capacity upto 350 mA

      Non-polarized capacitor working as a current limiting resistance, consuming around 15.6 watt power working as 3.18 Kilo Ohm resistor with no heat dissipation.

      Adding LED in series reduce Ampere in circuit brightness also reduces.

      Adding Capacitor in parallel Ampere increases in circuit brightness increases Resistance and power consumption by Capacitor increases

      Please correct me, if I made some miscalculation.

      I need is really power saving mechanism to light 1 watt led without much power wastage.

    • You should multiply the 0.68mA current with the voltage drop across the LED, measure both these magnitudes and then multiply them.

      Alternatively you can connect the ammeter with the input AC wires and measure the current and then multiply it with 220v….keep the meter range to AC

      Read CAUTION MESSAGE in the article

  17. I am new to electronic circuits. I have assembled the led driver circuit as explained by you. I have used1uf poly capacitor and .47uf in parallel. The electrolytic capacitor used is 4.7uf 250V instead of 1uf.

    I have connected 5 nos. 1w leds to the circuit.The circuit is not giving full brightness. Please suggest what is to be done to obtain maximum brightness

  18. Dear sir,

    Thank you very much for your quick reply. I have connected leds in series. Please confirm the low brightness is due to the change in the output capacitor?

  19. Hi

    We want to drive 3W Led (3.5V@700mA). Does 2UF/400VPPC at input and 1UF/250V PPC at ouput is sufficient to drive the leds.
    I just want to know one more information that the 56 ohm/1W is a normal 1 watt resistor or fusible resistor

  20. Hi Swagatam

    Thanks for this wonderful curcuit. I am having little problem. When I am trying to test the circuit my diode gets short in 2-3 seconds. Diode which is connected to 56ohms resistance and second end of the diode is makeing GND hence connected with ground led. Please guide me where is the problem. I have added 1watt led.

    • Hi Rahul,

      Thanks!
      It will be difficult for me to know the fault because the circuit is very straightforward and should start working immediately, in my house it is working very fine, may be the diodes that you are using are not good quality or duplicate ones, replace them with some other brand and see what happens.

      Regards.

  21. sir 1 baat btaiye ke ye cuircuit 1w ki led ke liye hai isi cuircuit pe hum 1w ki 15 led kaise drive kar sakte hai?muje 1w ki 15 led lightup karna hai kya is pcb me koi changes krna pdega plz help me out

  22. Hello Swagtam, friend i want to make a ac tube light with 10 1w led is this pcb working with 10 led's?or i have to change capacitor or else?
    Thanks

    • Hi friend,

      As mentioned in the previous comment, you may connect all the leds in series and connect the chain to the shown circuit. If the power looks less bright, you may connect another 1uF/400v in parallel with the input cap…

      Regards.

    • Thanks for helping me my friend.i m new to all this i m confused at 1 point.there are two wire 1 is coming from 1uf 250 capacitor.and 2nd 1 is coming from diode rectifier near 56 ohm resistance in diagram. do v have to attach both these wires with 56 ohm input ????

    • No, the broken link indicates that the wires are NOT touching each other, rather are overlapping.

      The wire from the diode is connecting to the 1u/250 and the LED but NOT with the 56 ohms wire.

  23. Dear Swagtam Thanks for this amazing circuit.
    Friend i m using this circuit with 10 led i had add 1uf 400v in parallel for brightness.but i can't get full brightness.
    i want glowing white bright.is that posible?

  24. Hi Swagatam,
    I was looking to drive 20 LEDs of 0.06 watts.
    So total Output voltage is 12-17 volts and total current is 0.08 amps
    to drive 4 strings of 5 LEDs each
    each led is 3.4 volts and 20 mA.
    Can you help with this?

    Also I would like to have an ambient sensor to switch on and off and a proximity sensor to switch to full brightness if some one approaches and to switch to half or 30% brightness after 30 seconds.

    I need this for commercial use. I need a simpel cost effective circuit. I have been following the blog and am sure that you know the subject. Please get back to me. You can email me at deepakjalihal@gmail.com or call at 09880718834

  25. sir my circuit was working perfectly from the last 10 or 15 days with 6 led but suddenly it gave high voltage and all the led are dead i check the output current of circuit with multi meter its high can u plz tel help me and tell me wats the reason behind this???

    • The design discussed in the above articles uses a 1 watt LED, which I think cannot be illuminated brightly using a 0.22uF cap. Using a resistor will generate a lot of heat, any other method too won't be cheap or effective and will fail to produce the amount of light the above circuit is able to produce….

  26. Very responsible and honest of you to admit that the circuit is not working anymore…

    1. pl check capacitor voltage and mA chart on internet. 1uF capacitor supplies only 40 mA. a 0.22uF supplies 20 mA.

    2. So, i think using 2 capacitors (224K) in parallel will keep voltage same – 3.5 v as output. However, amperage will be 20 mA from each – equal to a 105K capacitor.

    A third 224K capacitor across the led can be kept so that there is no voltage or current fluctuation.

    3. So the final circuit could be 2 capacitors in parallel, and a third to across the led.

    4. NO diode bridge is required and, as evident, no zener may also be required.

    5. rating of led is 300-350 mA. But a capacitor provides only 20 to 40 mA. So no resistor is required, since we want maximum current. By using a resistor, current would only get limited. For power ON, the third capacitor across the led will control both voltage and current fluctuations.

    reg
    ketan

    • Thanks!

      Adding two 0.22uF in parallel would make it 0.44uF, half of what I have used in the above circuit.

      When a 1uF cap is not able to illuminate the 1 watt LED with 100% brightness, with a 0.44uF the brightness would be further reduced?? Here we want to illuminate the 1 watt LED to its maximum rated value.

      Without rectification, the light will produce vibrating effect when our vision is under motion, wouldn't be pleasing
      to view…

    • I agree abt the amperage. But problem is not just mA, but voltage also.

      105k provides 24 volts… whereas 224k provides about half of it.

      I think it is the much higher voltage that burnt your LED, since amperage was below requirement.

      One way to reduce voltage is by lowering capacitor rating…

  27. Hi Swagatam,
    Your blog is very good.
    I want to share this.
    Leds are same as zener diodes. So voltage is not an issue. Current is the
    main factor which we should keep under consideration. Also an MOV or varistor or Gas discharge tube component is must(input side). Also to make galvanic isolation one can use small transformers.
    The above circuit must contain small heat sink on which led must be placed. More heat less efficiency and life on led.

    Regards,
    Pratik .R. Bhagat

    • Thanks Pratik!

      I appreciate your knowledge!

      Since the current is nowhere near the 350mA mark, the LED in the above circuit will never get hot, so a heatsink is perhaps not required here.

      Regards.

  28. Dear Swagatam,

    thanks for the wonderful simple diagram, please explain why 400v capacitors, what if 250V and can i use 470uf cap for the second cap with the LED.

    Thanks,
    Chaminda

    • Dear Chaminda,

      Thank you!

      250V caps will also work, 400V is selected for extreme safety against accidental high voltages which might exceed 250V.

      any value cap will do at the output as long as its rated at 250V

      Regards.

  29. i would like to comment on Mr Ketan's comment. You are asking to check capacitor voltage and mA chart on internet.Internet itself not creating and publishing any theory. what you read is also article of some human being.Mr Swagatam is also a good knowledgable person. PLS dont trust whatever you get from internet. according to your belief ,1uF capacitor supplies only 40 mA. and 0.22uF supplies 20 mA. Have you practically checked this?if you get 20ma from 0.22uf, you will definitely get around 80-90 ma from a 1uf cap.
    anyway according to my experience(practical) 1uf without series resistor can deliver around 70- 75 ma.
    if this circuit is not working for you, pls cross check your connections. i made this circuit and was ok.but life is not more. reason for that is explained by the author itself.
    yogesh

    • Yes Dear Swagatam,
      Amit Is Very True , i my self feel it that you are always helping and very Friendly, and always with warm welcome 🙂 to any problem and you give your best efforts and full attention to every persons problem.
      Thanks Dear I really Appreciate your love and help to others.
      Lots of Love and Regards

  30. Dear Swagatam…
    This is regarding the Chinese/ Rice Bulb Running Lighting, you must have seen the Box with COB,(Chip On Board) and 4 output connections for 8 different stages for running lights…
    Now I need your help, how to use this BOX to run LEDs of different colour…How many LEDs required in 1 string???

    • Dear PP,

      I'll have to study the circuit and then figure out a suitable modification for using it with LEDs, because as you know LEDs cannot be run directly on mains AC, so it will require quite many changes… I'll try to post it as a new article soon.

  31. mr.swagatam,
    i have 12W led circuit in which (IC-MIP 553) mainly manufacture by panasonic company is used,..
    but i did not found in my city (hyd),can u enqr in ur hometown reply me…plz….

  32. It's an interesting circuit but I'm afraid it's bad. the problem is that it flickers and there seems to be no way to prevent it. I've done a simulation and the cap in parallel with the diode makes no difference. no need to have it there at all.

    100Hz flickering is bad for the brain and should not be used for indoor lighting. you might think it's ok but you might also think the light from plutonium is ok. but it's not.
    we need a different circuit for proper powering of LEDs from mains.

  33. Hi Swagath, Happy Dewali, I assembled this circuit and tested and it is working, the 56E resistor is heating-up, can we change it to 5Watt one and add ten 1 watt LED's

  34. is it possible to connect the circuit to a dc supply in stead of AC supply. If so do we have to change the components in the circuit.

  35. My 1 watt LED's are 1.5volt, 700ma devices. Would your circuit run 1 of these devices. I could not see what output voltages and currents were being produced in your circuits. I was looking for a low voltage driver that offered PWM input so I could dim the LED (Using Picaxe Microcontroller) Any help greatly appreciated

    • Are they white? Are you sure they are 1.5V, because I have never come across white LEDs having 1.5V as fwd voltage.

      Anyway, the above circuit won't support anything above 100 mA so not suitable.

      The above circuit is certainly not recommended to be used in conjunction with microcontrollers due to its unpredictable nature.

  36. Hi sir i have connected circuit as you have given in curuit ,but at output insted of 3.3v dc i am gettingn 345v dc.

    Please tell ,me what is problem

  37. Hi Sir,
    I have prepare the above mention circuit with one 1 watt LED . Circuit working fine till half an hour.

    then i switch off the circuit and shift on other place . But when switch on the circuit, 1 watt led will not work.

    Kindly suggest the forward path

    Ripan

  38. Hi Sir
    I need help from u , actually I need to make a 45-50 LED series of bulbs for a picture frame,
    I have 4 IN4007 Diodes, one 474k 250v capacitor, one resistance 220k and I lost one capacitor for filtering may be 220uf 400v ,
    as I need to know the circuit diagram to glow these LEDs with 220v power supply. can u please suggest me if I need different values of any material.
    thanks
    regards
    Ravinder

  39. dear sir i want to on my energy saver without circuit mostly people say that 220 k 5 watt resistance use it but it not working any0ne can help me i want only saver tub on

  40. Hi Swagath Ji, Few Clarification
    Calculation of Capacitative reactance Xc=[(2*22/7)*f*C]^-1
    Oms Law for Power I=V/R
    If we use 0.47uf capacitor and frequency 60Hz in our power line
    Xc=(6.29*60*0.0000047)^-1
    Xc=564 Oms

    Power shall be I=V/R
    Our AC Line 230V
    I=230/564
    I=0.407691Ams i.e 407 mill amps

    Do we really get the above arrived amps ?

  41. Feed back, i found that when the circuit is used to run on a inverter power supply (230V, Square Wave) its 56E resistor gets burn out. i understand that it is because of the frequency in the power supply. The reactance of the capacitor changes with change in frequency. hope im correct. how dwe over com this problem to ensure the circuit runs both on direct power and inverter power?

  42. मजूमदार साहब नम:स्कार,
    मैंने आपके दिये 1 वाट एलईडी सर्किट बनाया बिजली से ठीक चलता है जब मैं इसे 650 va इंवर्टर से चलाता हूँ तो इसका 56 ओम्स 1 w गरम होके जलने लगता है !मार्गदर्शन करें
    एस।मिश्रा

  43. Hi Swagatam,

    I came across this blog of yours today and am very impressed. This is something I have been looking for.

    I am a total newbie on LEDs but very enthusiastic to learn. I want to use about thirty 1 Watt LEDs with heatsink (found on ebay.in) to generate 3000 lm of light, good enough to replace my 40W tubelight and get more light. Can you please help to design a circuit and also advise (with values) what components I need to build them to run on regular 220-230V AC?

    Regards,
    Uday

  44. Hi Swagatam,
    I tried your ckt above but the light was very low. So i tried experiementing with various capacitor values and found that 4.7uF 400v is the most ideal value. It gives around 260mA to a series of 3 leds. Voltage across the leds is around 3.2 volts.
    I however faced one problem. As a capacitor with rating of 400v was not available, i used 250v instead, and the leds were heating up too much even with a large SMPS heatsink. Does the Capacitor voltage rating cause this issue.
    Regards
    Janesh

    • Hi Janesh,

      Heating of the LEDs can be controlled by using a larger heatsink and by applying heatsink compound paste. heating of the leds is not an issue.

      However with a 4.7uF cap your LEDs are always at risk of getting damaged from switch ON surge currents.

      I would recommend a 12V 1 amp smps for driving the LEDs, that would be a permanent and a reliable solution.

    • Thanks for your reply.
      Do you have a circuit for constant current (350mA) LED Driver that are commercially available. It is very nice and compact and we can get rid of the capacitor i guess.
      Do post that circuit if you have.
      Thanks & Regards,
      Janesh.

  45. hi Sir thanks for sharing important information.
    sir i brought 5watt power led. this need 5v to 6v and 750ma. i dont have driver to drive this led.
    so can i drive on mobile charger coz his output also 5v. 700ma .
    and pls tell me which heatsink i use for this 5w led.

  46. hi sir i done this circuit. n use connect 1ps 1w power led its like a moonlight. its working in my room. only one ques. can i use heatsink for leds long life? bt my led is little heat.

  47. Hello. This may be way off topic, but I have a question regarding these 1W LEDs. If I were to buy a ceiling fixture (say 9W 9x1W LEDs) but the light fixture come with 9 white LEDs. Say I wanted to change some of the LEDs to blue, or red, or orange. How hard is it to pry off the white LEDs and attach a different color?

    • You can directly replace the existing white LEDs with LEDs of your choice, but the series resistor would also require some tweaking and replacement as per to the total forward voltage drop of the new series.

  48. Sir,
    All parts I used wr same as you said
    Expect the cap parallel to LED
    I used a 1mf 450v electrolitic cap instead polystr

    And led bust out wts the problem actually

  49. thank u soo….. much.i really appreciate ur grate work. i have prepared ur circuit.it is working well.but i have few questions.
    *cant we increase the current about to required limit of 1W LED safely
    *i want lighting three 1w leds.should i do any changes to kit.
    *5w led needs about 750mA and 6V.what should be the changes of kit.
    please reply me

  50. Hi Swagath,
    I found my spike buster LED running with only one single resister in series tat to of 150k 1watt….How does this works…?
    Mean all single single LED is connected with series resister of 150k each and tats it…It works fine..

  51. Hi Swagatam,
    Do I have to use a heat sink for the LED in this existing circuit and if not, can I use a heatsink and increase the brightness to its maximum? If yes how can it be done. Also im looking to light up say around 12-15 1W LEDs in 12V DC system (Battery), will that be possible with any circuit that you have designed. Please suggest. thanks in advance.

    Rajthilak K

  52. hi,
    thanks for simple and excellent circuit.

    Can I use this circuit to power up say 30 – 40, 1 watt LED in series.
    Does this circuit Heat up a lot, I am planning a Porch light Using this
    which will be auto Lit at dusk and would go off on Dawn using LDR.

    thanks,

  53. Hi swagath, If I use 82nF/400V Polyster capacitor insted of 1uF/400V and 220KE resistor insted of 1ME and 220uF/50V insted of 1uF/220V,is there any problem and also iam using MOV and NTC in my circuit. I want to connect 10mm LED 10 numbers in series. Now my circuit is working perfectly. I want to know weather any problem will come in future. or is there any mistake in my circuit. Help

    Thanks in Advance

    • Hi Industry,

      you have three protections included in your circuit:

      firstly the 1uF is reduced to 0.82uF, and also you have included two best safety options in the form of a thermister and an MOV, so I don't think you would have any issues with the circuit in the future…

    • Thanks Swagatham . Thank you for your quick reply. One more thing if I want make 3W,6W and 9W LED Lights ,what should be the correct matching value of Input capacitor and Output capacitor. Also please tell me how to calculate these values.My input volt is 230V and I want to use Each 1W LED'S.Please Help.
      Thanks in Advance

    • I won't recommend using the above design for driving higher rated LEDs because it's not very safe for it.

      You should go for SMPS circuits which will guarantee you complete safety with any type of desired LED

  54. Hello Sir,

    I want to use 1W LED through my 12V SMPS.

    Do 1W LED require heat sink bigger than what comes in the market for them (circular ~2cm in diameter) ,to run them at ~300mA ,keeping in mind there long life without much deterioration in light intensity.

    Thanks in advance,

  55. Hello there,
    Is it possible to have this circuit work for an LED with these specs?

    Reverse voltage: 4V
    Continuous forward current: 25mA
    Peak forward current: 100mA
    Power dissipation: 120mW
    LED junction temperature: 100°C
    Operating temperature range: -25°C to 85°C
    Storage temperature range: -40°C to 100°C
    Lead temperature: 260°C
    Forward voltage: 3.5V
    Reverse current: 60µA
    Luminous intensity: 1500mcd
    Peak emission wavelength: 468nm
    Dominate wavelength: 470nm
    Spectral line half width: 35nm
    Viewing angle: 35°
    RoHS compliant

  56. HI there!!
    now as far as I now there are SMD led Strips available in market which needs direct 12V supply so can we use them with a small voltage reg circuit with 7812??
    Thanks in advance
    with regards
    Amit

  57. Hi swagtam,

    your circuit is the best, thank you for sharing your knowledge.
    I want to use a 10W LED (12V), what change should I give to the circuit?
    I wanted to use one 10w LED in some places, 2 LEDs in others, and sometimes 3 LEDS (all in serie)
    thank you

    • Thank you for your replay,

      so in this case, I can put up to 20 (1W) LED in series with this circuit, as I read your comment above (in the beguining), but not in parralel?
      right?

  58. Hi Swagath,

    I need help. I want to make CFL Bulb of rating 1w, 3w, 5w, 7w, 11w, 13w, 15w, 20w, 25w, 33w. but i didn't get the circuit diagram of this rating. So please if you know the website or if you have this then please send me on sumit.rakibe@gmail.com

    Thank You…!!!

  59. Hello Swagatam!
    Thank you for all of your time answering everyone's questions. I would like to use your circuit design in a middle school project to create LED light fixtures housed in home cut and planed cherry wood housings. I am wondering which of your two posted designs you would recommend for this project, and how many 1 watt LED's you think would be appropriate for a 3 foot long bar type fixture to give an impression of consistent lighting when used as uplighting mounted above eye level on a wall (I am imaging a simple V design for the housing).

    Thank You!

  60. Dear Sir, i am no expert like you..

    i want to try build a led driver.

    the DC output should be

    14 Ampere (60 * 700mA) , 168 volt (2,8 * 60) , 60 Watt (60 pc * 1 W)

    since i want use 1 W led, DC2.3-2.8V 700mA each (read it on the spec of the bulb)..

    i want to use 60 piece bulb of 1w power led.

    is the DC out that i calculate is right or wrong ?

    • Dear Andre,

      You can use the circuit which is given in the above article, by connecting all the LEds in series to the output. Be sure to connect a thermistor in series with the input of the above transformerless power supply and increase the input capacitor value to 5uF/400V non-polar

      Your current calculation needs correction…..when LEDs are connected in series the current gets shared, meaning in your case the current would be just 700mA…..
      By the way 1 watt LEDs are rated at 350mA not 700mA, I am doubtful about your specs.

  61. Sir

    when i have made this circuit i got only 2.82 volt on each 1 Watt led.. so pls help me how to increase volt to 3.3V…
    I have used following items…
    1. 105K/400volt capacitor
    2. 150 or 570K resistance for cap
    3. 4 diode 4007
    4. 56 ohm resistance 2 watt
    5. 100V/100mf condenser
    6. 1watt 3LED in series

    • Hi Vivek,

      Increasing current won't be a good idea and is not recommended for such power supplies, instead you can use ordinary 5mm LEDs and connect 50 of them in series, it will produce much higher illumination than a three 1 watt LEDs.

  62. Can you please provide me any link, or provide me some hint to understand how did you arrive at the input side capacitor of 1uF/400V? I mean how does this value of capacitor restrict or limit the current that is being used by power-led? Also how are we restricting the voltage supplied to the led to 3.4V. I know that even if we provide 5V to the led the forward drop will always be 3.4V; but still if we provide a higher voltage maybe something like 200Vdc then I believe the led will burn out. Then how do we limit the voltage supplied to the led?

    • The current is important here which we want to limit by putting a resistance in series with the mains, the capacitor acts like a resistance here which is calculated by calculating its reactance, you can Google a little to find the formula for reactance, this will be in Ohms, next you can employ Ohms law to calculate the current that can be limited through this reactance or resistance.

    • The voltage gets automatically restricted to load voltage only in case the current is considerably lower than the maximum spec of the load (LED here), since a 1uF/400V can allow a max of 70mA which is far less than the 1watt LEDs 350mA, the voltage settles down to the LED FWD V level

  63. HI this is Arjit Sharma
    i have got 10 x 1 watt led
    6×1 white
    2×1 red
    2×1 green
    but when i connect it in parallel connection to 10 w 350 mA driver on red one light and that to with only small amount of brightness why so and what do i need to do for lighting them with full capacity

    9928036395

  64. Hi sir I'm planing to connect 40 1 watt led's in series so i want to add an fan speed controller for dimming. I'm interested in electronic but i don have much knowledge in electronic plese help me can u send me the pic of ready circuit for reference wajedpasha58@gmail I'm waiting for Ur reply

  65. Dear Swagatam Majumdar
    I am interested to know that how much wattage will be recorded or shown by the electric meter if we are using your 1watt LED circuit with four LEDs in series?
    Yes, I appreciated your efforts made to satisfied every person, I read already.
    Regards.
    Muhammad Ali Shaikh, Karachi, Sindh

    • Dear Muhammad,

      You will have to measure the volts across the leads of the LED, and measure current in series with the LED, then multiply the results to get the wattage.

  66. how to lighten up 20 LED of one watt each connected in parallel , n how many voltage require i have a 35voltage DC battery and how to control upcoming voltage from battery to glow much brighter

    • with 35V you get an opportunity to connect 10 LEDs in series with a single limiting resistor, so with 20 LEDs you can make two such strings and connect them in parallel.

      The resistor value will be 6 Ohm 1 watt for each string.

      The above set up will produce the most optimal response from the LEDs

  67. Hello Sir,

    I have seen your posting of 1watt led drive from mains supply its good i have tried but,
    my led has blown out and i have checked the out put is showing 320v Dc..
    I have used the the below parts..
    1) 1N4007
    2) Resistor 1mego ohm 1/4watts
    3) Resistor 56ohms 1watt..
    4) capacitor 105/400v polyster type.
    5) Capacitor 104/250v polyster type.
    6) LED 1watt white.
    I have connected as per the draw shown above kinldy le me know where im doing the mistake..
    mains voltage i have given 240volts to the above circuit..
    Kindly help me sir…
    Hanumanth

  68. Hi, Can you guide me with making of LED Street light using 30 Nos. 1W SMD LEDs connected in 3 rows in parallel with 10 LED's in Series. I will use available ready-made good LED Driver (pls give spec of Driver required). Thanx

    • Hi Naresh, It would settle down to the 100uF capacitor voltage rating without load. and when a load is connected such as an LED it would further come down to 3.3V

    • Sorry that's not possible, you will have to include a transistor stage also for reliability and safety because at 0.5amps the initial surge will be too high which could damage the load instantly.

  69. hai sir,
    i am aravind
    while i am surfing through internet i found that 1uf cap will provide 40ma.
    then how it glows 1 watt led which requires 300ma.
    does 40ma amp is enough?
    please explain.

  70. Hi Swagatam, i like your blog. i have question related changing "2pcs of 4,7uf/250v and 2 pcs of 10 ohm/1watt with 1 pcs of NTC. what value of NTC of it? is it 20 ohm?

  71. Hello Swagatam,

    i have followed ur ckt . i want to connect the 18 LED having voltage 3.2V Current 150mA . i have used the 105J 400V capacitor . on AC side the current consumption is 70mA while on DC side at led it is 55mA only . I want to insincere the DC current at led side up to 130mA and decrease the AC current up to 30mA.

    Kindly suggest mi how to do that

  72. Dear sir,
    this is Shrinivas from Amravati.
    How can be modified this circuit to draw 20mA (for single 5mm LED)? Coz I've tried single 5mm for this circuit bt it lits very brightly which is resulting high temp & no durability. So please suggest exact value (for R?)
    Thank you so much sir.

  73. Dear sir,
    I want to attach it a single 5 mm led to project its beam on the wall clock.
    So how can be modified this circuit for a single 5mm led? (enough brightness which shouldn't harm led's durability)
    Thank you so much sir.

    • use a 0.33uF/400V capacitor in place of the shown 105/400V cap, you can try a 0.22uF/400 first if it does not give sufficient light then go for the 0.33uF/400V option

  74. dear Swagatham, in reference to the simple single diode schematic diagram : can I replace the 1megaohm resistor in parallel to the 105uf 400v ac capacitor with a neon bulb instead? the 1 megaohm resistor is a simple discharge mechanism to prevent the cap from keeping its current in it and causing a shock when touched accidentally etc whilst being removed from the ac outlet right?

    • dear fidel,

      you can use a neon bulb in series with the 1M resistor…..but you cannot replace it

      that's right, it's for discharging the dangerous mains potential when the circuit is unplugged

  75. Hi friend,
    How are you? hope u doing gr8, I am again in little confucsed with led current value, i mean i went to market few days ago to buy 50nos 1w led, but in one shop i got only 20nos and another shop i got 30, so i got total 50nos. Ok after taht i came to home and connect led's to desire voltage (output voltage of battery is 3.2v) the 20nos of led (from 1st shop) brightness is ok, but another 30nos led (from 2nd shop) brightness is different, my question is how to know led current value, i mean 350ma or 300ma? is there any calulation method or any way to check the led current????
    Thank you….

    • Hi friend, I don't think there's any testing equipment or method which will identify the wattage of an unknown LED??

      but in your case it's just because of difference in quality or color spec….both could be 1 watt/350mA but due to different brand, the illumination could be slightly different.

    • Baron, the over voltage can be simply stabilized by putting a zener diode across the LED terminals, and the spike or transient can be controlled by inserting an NTC thermistor alone or in conjunction with an MOV 😉

  76. Hi friend,
    I liked 2nd diagram, but I don't have 10uf 250v capacitor at the moment, currently I have:
    10uf in 16v, 25v, 50v, 63v.
    so what capacitor voltage I can use instead of 10uf 250v??? please suggest me.

  77. Luego de casi un lustro llega a Sur América problemas para resolver tecnolócamente que ud mi estimado amigo ha resuelto y compartido… gracias… hacía hace un tiempo este circuito para leds de 60mW y me preguntaba si funcionaría con chups de 1w. Saludos y gracias.

    After almost five years come to South America to solve problems you my dear friend and shared resolved … thanks … some time ago this circuit 60mW LEDs and wondered if it would work with chups 1w. Greetings and thanks.

  78. Hi Swagatam,
    I have been following your blog for quite some time.Its a very good blog and I have made many circuits by following your circuits. I wanted to make led street lights but the frames i have are the old types you know those 40 watts one. So can you tell me how to make them like the circuit and what type of led's can be used to have bright white light.

    • Yes, make sure all the parts along with the 1N4007 diodes are original, and of good quality.

      use a 12V / 1 watt zener across the output +/- lines, this will prevent the capacitor from getting damaged.

      remember this circuit is for 1 watt LED, NOT for 20mA LED, if you want to use 20mA LED then replace the 105/400V capacitor with a 0.22uF/400V capacitor.

      please don't do anything without understanding

    • Raja, yes that's possible but NTC will need to be placed in series with the supply, not at the points where diodes are connected.

      it will prevent surge but it will not stabilize the voltage, and it is recommended only for initial switch ON current control not for round the clock control

      15 no LED can be used, but should be in series

  79. Hi Swagatam, i tried the basic transformerless circuit from u r previous posts and ive used single 1 watt led but resistor started heating up. I am using 474k/400v cap and single led (1 Watt) . since there r many ckts in ur site which uses 1uF cap suggest me a ckt suitable for me….



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