## 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

Another interesting way of controlling the involved switch ON surge could be by using a SCR crowbar circuit stage as shown below:

As can be understood from the above diagram, the SCR is configured as a shunt regulator circuit through the zener and the associated resistor network. The zener value decides at what voltage level the SCR is supposed to conduct and control the voltage.

Here it is fixed at 4.7V, which implies that the voltage across the SCR anode/cathode terminals can never exceed the 4.7V value.

This further ensures that the connected 1 watt LED would be always getting a safe voltage of around 3.5 to 4V which is quite manageable for the LED, provided it's mounted over a suitable heatsink.

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

#### hitman

Hi Friends, Welcome to my site, a place where you will discover a massive collection of electronic circuit ideas, mostly requested by the dedicated readers and exclusively designed by me for their customized application needs. I have posted more than 1100 circuit designs in this site, if you have a personalized circuit requirement you may feel free to request it through the comment box, if it seems feasible to me then surely you may find it published here with your credentials attached in the post, thanks and please keep reading>

1. 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

1. Hi Sam,

Your appreciation always comes from the heart, and that's what inspires me to write more and come up with new concepts.

Only thing I can say that this blog and me are "alive" on the internet only because friends like YOU are with me....:-)

God bless you!

Thanks very much....do keep writing to me!

2. Dear sir, how to make it glow normal white led with only two 1.2v nicd cell? Please give the circuit sir

1. Hi Rajs,

Adding two 1.2 cells in series would give just 2.4 volts, not enough for illuminating a single white LED (any type).

You will need a boost circuit for making the above condition work, please check out the article explained in the following link, it will probably help you to fulfill your requirement:

Regards.

3. Hi,
Is there any circuit like this with multiple 1 w LED's?

1. Just connect them in series in the above explained design....

4. what type of capacitors are being used?

thanks...

1. High voltage PPC types, see the last figure,

Thanks.

2. 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

3. do not use 3.3uF, use 1uF/400V, remove the output polar capacitor, use 56Ohms,2 watt resistor it's required, it will not get hot with 1uF/400V capacitor.

By the way please refer the following article also:

4. 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

5. 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.,

6. 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????

7. 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.

8. 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

9. 3.3uF is far too big, try tw0 1uF/400V in parallel, that will keep things in control.

5. what type of capacitor is it? electrolytic or polyester...

thanks..

6. 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

1. Hi,

There's no limitation, you can go on to connect any number of LEDs....upto 50 at 220V input

Regards.

7. 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

8. hi there Swagatam,

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

Thanks a Lot,

1. Yes you can use it, but you will need to replace the left side 1uF cap with a 0.33uF/400V capacitor.

9. Hi,

what is the difference between polyester and mylar capacitor?

tnx

1. Mylar is also a kind of polyester, so they both come under the same category.

2. Hi Swagatam,

i use 0.33uF/600V (334) but it's not working, if i used 1uF/600V its working but it now glow bright. what could be the problem?

Thanks,

3. If it's too bright you can reduce it by adding a resistance in series with the LED, use a 100 Ohm 1 watt resistor in series.

10. 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?

1. 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.

2. 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,

3. 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.

11. hi
swagatam i want to connect 4 1 watt LEDs to mains how to connect those to this ckt?

1. Hi Swagatam,

You may use the above circuit, just connect 3 more leds with the shown LED, in series.

2. thanx for reply , can i use this ckt for 1 watt IR LEDs ? and upto how much power it can supply, can i use this ckt for battery(3v,6v,12v) charger like Chinese. torch lights.

3. Yes you may use it for both the applications.

4. can i contact u on facebook.

5. can i do something more for extra brightness.reducing resistance causing LED damage .

6. You may increase the value of 1uF to 2uF

7. I mean the input cap 1uF/400v.....

8. should i connect two 1 uF/400v capacitor in parallel ?

9. yes will do.

12. 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.

1. Hi,

You may use the above driver circuit, connect all the 60 leds in series and connect their end terminals to the circuit's output.
Regards.

13. hi sir, can we use your circuit overnight? and it will only consume 1 watt of power? thanks

1. The circuit will not consume more than 1 watt, for sure.

14. dear Swagatam,
Is there any circuts for 3w led or can I use this circuit Changing some parts....?

1. Yes you may use the same circuit, just make the input cap to 2uF/400V

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

1. Parallel....Thanks

16. 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.

1. 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.

2. 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)

3. 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.

4. 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.

5. A simulator is never always correct, so it's better to build it practically and check the results....

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

7. You will have to increase the input cap value for 3W LEDs,

The voltage will drop from 220V to 3V when connected, so there's no danger to the LeD...

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.

9. Try with a 1uF/400V, I am using the circuit since last one year in my house and it's working very well.

The input capacitor should be metallized polyester type.

17. 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

1. 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.

18. 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,

1. 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.

19. Sir...
Do need to connect all 20 Nos. 1Wtt LEDs in Series or Parallel???

1. Connect them all in series

2. 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...???

3. Actually 50 nos. will be OK, and will give good illumination, at 60 it might become dim

4. 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,

5. 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.

20. Thank You Swagatam...!!!

21. Hello..Swagatam...!!!

Are these LEDs tend to Fade away after a period of time???

Regards,

1. 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.

2. 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 HÃ¶lzl (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.

3. I tried to explore over the net but couldn't find any info, if you could show me the pic of it then may be I can investigate.

22. Thank You...

23. 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.

1. I think this circuit too trivial and insignificant to be considered for PF corrections etc,

2. 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...

3. 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..."

Regards.

24. 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?

1. Hi Sameera,

Connect the LEDs in series, to increase the brightness you may try adding a 0.5uF/400V capacitor in parallel with the existing 1uF/400V capacitor.

25. You say can put many leds in "series", wouldn't it be in parallel?

1. No, parallel connection won't work, it has to be in series only.

26. How about using 3 leds of 3W (4V - 700ma)?

1. Can be done...the input capacitor will need to be increased from 1u to may be to 2 or 3 uF...and the leds will need to put in series.

27. 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).

1. 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....

28. 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 ?

1. All the values in the diagram are correct.

The input capacitor should be 105/400V or 1uF/400V/450V

check your led with a 3 volt button cell to confirm it's operation.

29. 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

1. Please measure and check the current with an ammeter, a 1 watt led will never consume 15 watts....

2. 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/(2Ï€•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

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

3. 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

30. 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

1. How did you connect the LEDs, in series or parallel? It should be in series.

The output capacitor is not electrolytic it's PPC

31. 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?

1. Remove the output capacitor for time being, also tell me the value of the input capacitor....tell me the print value..it should be 105/400v

32. The input capacitor i am using is 105/400V and 474K/400V in parallel

1. Check the brightness after removing the output capacitor.....

2. Dear sir,

The brightness is little improved. i would like to know what is the function of output capacitor? what will happen if it is removed from the circuit?

3. Output cap is for filtering and absorbing surge current during initial switch ONs. Nothing much will happen if removed....

4. whether 474K, 400V poly capacitor can be used as output capacitor?

5. yes can be used....

33. 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

1. Hi,

According to me 2uF/400 and 1uF/250 should be OK.
All resistors are normal CFR type.

34. 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.

1. 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.

2. Thanks buddy I have found the problem. Problem solved. Excellent circuit.

35. Hi Swagatam

What if I add 1mfd400v electrolytic on output instead of 1mfd250vPPC. Will it work.

1. Hi Rahul,

I think it should work, because the current is limited at the output, so there's no danger of an electrolytic cap blowing off.

36. 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

1. You may connect all of them in series to the above circuit, according to me no changes in the design would be required.

Regards.

2. thanks for reply sir but i m facing a problem jaisa aapne btaya maine waise he pcb accemble kiya or isey 1w ki 1 led ke sath check kiya jaise he ise ac power se connect kiya after 1 min led burn hogyi can u plz tel me where i m wrong jo component aapne btaye maine same use kiye hai.....

3. send me the picture of your unit to hitman2008@live.in, let me see what you have built...then I'll try to trace out the fault.

37. 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

1. 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.

2. 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 ????

3. 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.

4. Thanks so much my friend.
You have a golden heart to spend your time to help others.

Regards

Karan

5. It's my pleasure...Thanks!

38. Sir i had add only 1 led on this ckt but its not giving me full brightness.i had used 1uf 400v and 1uf 250v.

1. I used a single led too, and it produced very good illumination as you can see in the pics....not sure what's the problem with your circuit.

39. 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?

1. Dear Suraj,
Thanks!
How did you connect the 10 leds, they should be connected in series and not in parallel....

2. yup its in series.my led's are bright but not fully bright.
if i drive 1 led with mobile battery its giving me full white brightness ,i want that kind of brightness.

3. With a capacitive power supply you won't get extreme high bright illuminations, this is probably the maximum that you can get, try adding one more capacitor in parallel, see what happens.

40. 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

1. Hi Deepak,

I'll try to design it and inform you when it's done.

2. Hi Deepak,

I have tried to fulfill your request here:

41. 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???

1. It is probably due to current surge, add a 30V/1 watt zener at the output of the circuit across the LED series, this might help to control sudden high influxes.

2. 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....

42. 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

1. 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...

2. 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...

3. LEDs get damaged only during switch-ON, due to initial surge voltage.

If this initial surge is controlled, LEDs will never have the risk of getting destroyed.

43. Hi Swagatam,
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

1. Thanks Pratik!

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.

44. Dear sir
how can i use 10w led for this circuit

dheeraj
Trivandrum

1. Hi Dheeraj,

The above circuit is not suitable for driving a 10 watt LED, you will have to use a small 12 smps circuit for it.

45. Dear Swagatam!

I'm here in Brazil and your blog is so cool!
I need your help because I want install a LED (1 watt) in a switcher dimmer (220V). Which is the right way?
Thank you!

Carlos

1. Hi Carlos,

Thanks very much.

Presently I am not sure about the answer, I'll surely tell you after I figure it out.

Regards.

46. 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

1. 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.

47. 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

48. Hello Swagatam

You are really doing great job.
the best part you really take pain to reply any queries without frustration.

Great going... Keep it up.

1. Thank You Amit! Appreciations from readers like you keeps me motivated.

2. 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

3. Dear Itech,

This blog is running due to the best wishes from you all...and I am enjoying that.

Lots of love to you also...God bless you.

49. Dear Swagatam...HAPPY DEEPAWALI !!!!

1. Dear PP,

Wish you all the same!!

HAPPY DIWALI TO EVERYBODY!

50. 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???

1. 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.

51. Swagatam.....Really feel Honoured for your kind reply that too on same day..!!!

1. It's my pleasure PP...

52. It's My Pleasure too...!!!

1. I appreciate that PP...that's great :D

53. mr.swagatam,
i have 12W led circuit in which (IC-MIP 553) mainly manufacture by panasonic company is used,..

1. Hi dmpl

This IC is very difficult to find I have inquired with the local dealer and he has no clue about it.

54. 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.

55. 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

1. Happy Diwali to you too.

Yes you may use a 5 watt wire would resistor. You can also 10 1awtt LEDs in series, but please read the highlighted red colored text in the article.

2. I suggest to add a MOV at the start of AC line to handle trns current. will it be ok to have a stable supply

3. Yes it can be connected, one lead after the input capacitor other lead before the 56 Ohm.

However it won't be cheap anymore as referred in the title.

4. Ok, any specific rating for MOV, a regular one cost Rs.5-10. to connect one end after step down capacitor and one end before the 56E(5watt). 56E 5watt is quite fine nd does not get heated.

5. Any standard or regulaer MOV for Indian voltage conditions should work.

That's fine, I think you can go ahead with it.

56. hi sir i am saurabh,my problem is that 56omhs resistor burst when power is on,i double ceck the circut....but problem is not solved.

1. Hi Saurabh,

Use 474/400V capacitor in place of 105/400V or try the circuit given at the end of the article.

57. Can we connect MOV before DC conversion to handle trans current?

1. I think it can be connected there.

58. 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.

1. No this circuit is intended solely for AC mains, you can use the below given circuit if you want a DC operation:

2. Thank you u rock

59. thanks a lot for ur help dear...

60. dear sir! i want 100watts LEd Driver circuit with 220volts AC input

1. Dear Munib,

You will have to use a readymade SMPS or transformer power supply for powering 100 watt LEDs.

You may refer this article for knowing how to configure the LEDs in series and parallel.

61. 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

1. 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.

63. 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

1. Hi Kunal,

Please make the last circuit shown in the following article:

64. 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

1. Hi Ripan,

65. 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

1. Hi Ravinder,

If you want to illuminate them constantly without flashing or blinking then you may try the following circuit:

66. 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

1. energy savers comes in neat, self-contained cabinets, how do you want to modify it?....i did not quite understand.

67. sir,
can i connect this light to inverter (square wave output) ??

b.philip

1. yes...no problem.

68. can i connect 5mm led to this ckt. if yes how many led ?? parallel or series ???
thanks.

69. 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 ?

1. I think you are one digit wron with 564 ohms, it should be around 5640 ohms..also the frequency should be 50 Hz and not 60 Hz.

You may use this site for easy calculation:

http://www.sengpielaudio.com/calculator-RC.htm

The ohms law calculation method is correct.

2. You are right, 0.47uf converted in to Farad should be 0.000000047. Thank you once again

70. 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?

1. make this circuit, you won't require any resistor:

http://2.bp.blogspot.com/-nKF8T8lKIxY/UMg7YDLNQ3I/AAAAAAAAB8U/S1OWTK0cMD4/s1600/Surge%20free%20transformerless%201%20watt%20LED%20driver%20circuit.png

by the way, the frequency of the inverter will be the same as our mains ac.