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    This white LED flood lights illuminates your porch with cool white light. The circuit is too simple and energy saving design. Its current consumption is practically nil but can provide light like a 20 watt CFL lamp. It is directly connected to AC lines to eliminate a bulk transformer.

    Ultra white LEDs are now replacing the fluorescent lamps due to its energy saving property and simplicity of design. White LED emits 1000 to 6000 MCD light and easily works on 3 volts at 20 mA. White LEDs are available as spot light and diffuse type versions. Different sizes like 3mm, 5mm and 10 mm varieties are now common. High watt single white LED is also available. White LEDs was introduced in 1990 which uses Indium Gallium Nitride (InGaN) as the semiconductor. White LED contains a blue chip with white inorganic Phosphor.

    When blue light strikes the phosphor, it emits white light. The circuit uses capacitive reactance to drop high volt AC to low volt AC. This reduces power loss due to heat dissipation. The value of the AC capacitor can be calculated using the formula X c= 1/ (2 π f C) where, Xc is the reactance in ohms, C the capacitance in farads and f the mains frequency. Xc = Vrms / I where Vrms is the input voltage and I is the current flowing through LEDs. The low volt AC (around 100 volts) dropped by C1 is then rectified by a full wave rectifier formed of D1-D4.

    Schematic of the LED Flood Lights Circuit

    white led flood lamp circuit schematic

    Capacitor C2 act as a ripple remover and buffer. Zener diode ZD regulates DC to 69 volts and prevents excess reverse voltage across the LEDs during the negative half cycles. R1 is a must in the circuit to bleed the stored current from C1 when the circuit in unplugged. C1 can store more than 400 volts for many days if R1 is not connected. This can give a lethal shock.

    R2 reduces the inrush current. 20 LEDs are connected as a string to obtain luminance equal to 20W CFL. Enclose the circuit in a shock proof case. If a reflector is provided behind the LEDs, it will give a flood light appearance.

    Important! Do not touch any points or trouble shoot when the circuit is connected to mains.

    Caution This is an AC powered circuit and can give fatal shock if handled carelessly. Do not construct the circuit unless you are competent to handle high volt circuits.

    attentionThe author D Mohankumar is not an active member anymore. Please take into consideration that the presented information might not be correct.
    ask a question

    138 Responses to "White LED Flood Lamp Circuit"

    1. Is the value of C1 correct? Is it .225 uF?

    2. X rated high volt Ac capacitors are usually expressed as K. You can use 0.22 uf in the place of C1. To get more current it is better to use 105k or 225k

      • Chinmoy Mitra says: on March 1, 2011 at 12:57 pm

        Sir, as far as I know, 225k means 2.2uF, polyester capacitor, 105k means 1uF capacitor (high voltage types of course), same as 224 means 0.22uF and 104 means 0.1uF. These are regularly used in cheap led lights made in China.

      • can you send me a equivalent circuit operating with led having equivalent power as 45 watt CFL.also give me some tips
        for spreading the light through out the room instead of directing to one side

      • I don’t know

      • Can I use 7W/6500K DC CFL (4 pin) Bulb in this circuit

      • sir
        if i put Metal Oxide Varistor(MOV) in this circuit ,, then where should i put MOV component and what is the value should be…
        i want to do a LED tube tight



      • hello sir, i want a 2.1 audio system(power full) circuit,and components details so please send it on to my email(mohanrajece48@gmail.com) id.

      • subhendu ghosh says: on October 7, 2014 at 6:14 pm

        to illuminate whole room, you should use SMD led instead of normal 8mm, 4.5mm led.

      • dharmendra says: on January 11, 2015 at 5:38 pm

        Sir. Thankyou

      • Tonmoy Dutta says: on October 17, 2015 at 10:16 am

        If you got circuit and found success, so pls. share me.
        9836529567, india, west bengal.

      • 225K is 22*10^5 pF with 10% tolerance = 2.2uF/10% tolerance. Tolerance values indicated by letters are shown below.

        E +/- 0.5%
        F +/- 1%
        G +/- 2%
        H +/- 3%
        J +/- 5%
        K +/- 10%
        M +/- 20%
        N +/- 30%

    3. how can it be 1/2.2 uf (105k/225k),when led can bare typically about 30ma.0.22uf may be do the trick with 22ma peak,where 105k delivers 100ma peak ,with which the led does-not compatible.

    4. Dear sir, I could not get Zener diode 69 V 1W as it is not available in the maket (hyderbad ) I enquired with number of shops. Zener diode 56V and 75 V of 1 W are avilable. Kindly advise me which to use and how to use. V.GOPALAKRISHNA

    5. Replace ZD with 75 V zener and add one more LED. If you use 56 V Zener then remove 4 or 5 LEDs

      • gopala says: on May 24, 2010 at 6:03 am

        Thank you Sir.

      • sir
        is that possible to put ZD with around 100v or so on(25-30 led)… ?to put more LED…and sir ..C1 value 225K and 225J is there any deference ?

        and MOV and NTC which one i should put in the circuit spike ,,,and where i where should i put in the circuit ?



      • K(±10%) or J(±5%) indicate tolerance.

        For voltage surge protection, use a MOV.

    6. Dear Sir,
      I hope to use LED with below speciation
      • Forward Voltage (V) : 3.2 ~ 3.8
      • Reverse Current (uA) : <=30
      • Luminous Intensity Typ Iv (mcd) : Average in 20000
      • Max Power Dissipation : 80mw
      • Max Continuous Forward Current : 30mA
      • Max Peak Forward Current : 75mA
      • Reverse Voltage : 5~6V
      So is there any modification need to this project?

    7. You can use these LEDs. If the brightness is not sufficient, remove one or two LEDs

    8. V.GOPALA KRISHNA says: on June 9, 2010 at 8:11 pm

      I assembled the above circuit with 21 LEDs (10 mm white), 0.22 uf capacitor 400 volts and a zener diode of 75 V one watt. It is giving very good / bright light of its range, i.e.
      with 21 LEDs. The light increased further when I added one more 0.22 uf capacitor 400 Volt in parallel with the original capacitor. I fitted the above circuit in a good quality shockprrof,transparant plastic box of size about 3″ x 5″, available in Supermarkets. I also fitted to the box a two pin plugpin with micro bolts so that it can be put into the plug socket safely. I am using the light in my varandah regularly. I suggest to
      the hobbyist to assemble the above circuit, if not done, and enjoy. Thanks to Sri D.Mohankumar for giving the above circuit. V.G.KRISHNA, Hyderabad.

    9. hye mr mohankumar,
      if i were to use this circuit to fully utilise the 12v 5w LED, would it be sufficient?any components that i need to change? thanx

      • D.Mohankumar says: on July 5, 2010 at 5:37 pm

        Current for 5W LED is not sufficient in this circuit. Use the circuit POWER LED LAMP posted

      • Mcshazzy says: on July 5, 2010 at 5:52 pm

        Thank you very much sir

      • sir
        can i use 100uf 100v for c2 . zd 69 is nit avaliable here can i use 2zd 35v 1/2 to make it 70 v 1w .

      • Jim Keith says: on July 25, 2012 at 12:21 pm

        100uF is too low in capacitance as the peak-to-peak ripple works out to about 15V (without the zener connected). 1000uF works out to about 1.5V P-P ripple. I think you can get away with 470 or 500uF, but 100uF is too small.

        On the zener, (2) 35V devices in series will work fine.

      • thanks for replay .
        can i use 470 uf 100v,

      • 470uf or 500uF 100v is not avaliable what to do.50v avaliable

      • Jaspreet says: on October 3, 2014 at 7:58 am

        Dear Mr. Keith,
        Can you kindly explain the formula used for calculating smoothing capacitor value.

      • Jim Keith says: on October 3, 2014 at 12:12 pm

        Check out this article for calculating power supply filter capacitors:

      • Jaspreet says: on October 4, 2014 at 4:41 am

        Dear Mr. Keith,

        Thanks for the very useful link. For 220v 50 hz full wave rectified dc as in the case above, I am using the formula like this.

        Vp-p=(70% * 50 ma current drawn by leds in series) / ( 2*50hz * 100 uf)
        = (.7*50/1000) / (100*100/1000000)
        = 3.5v

        And for 1000uf capacitor the value is 0.35v. Will 100uf be considered still low for this circuit? Or am I missing something? Does it matter if Zener is connected or not?

      • Jim Keith says: on October 4, 2014 at 5:07 am

        100uf is OK for your application –I just would not go lower. The zener is a safety valve to prevent the voltage (over 300V) from ever exceeding the capacitor working voltage rating in the (not unlikely) event the LED string is open due to LED failure or mis-wiring.

      • Jaspreet says: on October 4, 2014 at 5:27 am

        Thanks Mr. Keith for explanation and taking out time.

    10. Sir,

      do you have direct ac-line circuit for 1watt LED white?

    11. You may search Power LED lamp in the same site. It is AC powered. We cannot connect the LED directly to AC. Step down is necessary

      • subrahmanyam says: on November 3, 2014 at 3:11 pm

        Dear Sri. D. Mohankumar. My understanding is that LEDs are constant current devices. Which part of this circuit does that job of keeping the current constant.

        Sorry, I am electronics illiterate, or only slightly literate.

      • Hi subrahmanyam,

        LED of different color will work within different voltage range. For example, a white LED may be manufactured to work within a 3.0-3.5V range, and the current consumed by the white LED will depend on the magnitude of the voltage applied. At 3.2V, it may consume 20mA; 10mA at 3.0V and 70mA at 3.5V. The LED will consume a constant current at a specific volatage within its working voltage.

        In this circuit, the output voltage has been regulated by the zener diode(ZD) to be 69V. Since there are 20 LEDs in series, the applied voltage on each LED = 69 / 20V = 3.45V. Depending on the SPECIFICATION of the white LED connected, at a voltage of 3.45V, the current consumed may be 60mA.

        Since the circuit is supplying roughly 100mA current, any surplus current will pass through the zener diode. In my hypothesis, (100 – 60)mA = 40mA current will pass through ZD.

        One problem of this circuit is the rating of R2. Power dissipated by R2 = I^2 x R2 = (0.1)(0.1)(100)W = 1W. For safety, add 50% margin, the rating should be at least 1.5W. A 1W rating resistor will become hot to touch very soon.

        Another area worth of notice is the zener diode rated at 1W. As it is a 69V diode, 1W rating means it will safely allow a current of 1 / 69A = 14.5mA to flow through. Therefore, the forward current of the LED connected should be at least 85mA at 3.45V. Otherwise, the zener diode will overheat as it has to take up all the surplus current left.

    12. Dear Sir

      When switch off this light, at least 50v to 100v store in the C2. How can I remove this current?

      Thank you,

    13. Connect resistance between + and the ground. This will discharge C2

    14. Hi Sat,

      How to connect the resistance between + and the ground, i’m new to this thanks.

    15. Hi Sat,

      I connect the 100R 1W resistor between + and ground, but after that bulb are not light up

      what should i do?

    16. Dear Mr.Kumar

      If the capacitor C2 stores current, you can do 3 tips. Reduce the value of C2 to 100 uF 100V or reduce the value of R1 to 100K 1W .Best method is to connect 1Meg 1 watt resistor parallel to capacitor C2.This bleeder resistor will slowly remove the current in a few minutes.If you connect a 100R resistor, all the LED current will drain through the resistor. Use 1 Meg or 2.2 M. Dont reduce the value below I Meg

    17. Thank you very much Mr. D.Mohankumar

    18. Hi Mr.D.Mohankumar,

      If want to increase the LED’s from 21 to 24nos what component should replaced ?

    19. Hi Mr. Tony
      Each White LED requires 3 volts minimum. Add 4 LEDs in the same circuit. If the brightness is too low,add one 105K AC capacitor also parallel to C1 to increase current and voltage.If brightness is too high, increase the value of R2 to 470 ohms 1 watt.

    20. Hi Mr.D.Mohankumar,

      If using 24 LED, capacitor 100uf 100v and ZD 68v 1w will it effect the brightness ?

      Thanks for valuable information.

    21. In chennai , we do not get 1W zener diode . we have on only 1/2 watt . What to do ?

    22. mr mohankomar can i use 225 or 105 k 630v in c1

    23. dear sir how we can step down the voltage by transfarmer or any component

    24. Dear sir
      pleas send me the circuit for 50, 100 and 150 LED for 220v main supply

    25. 105= 10,0000Pf= 1uf

    26. sir
      I Assembled the circuit but iam geting 140v as i ve used 75v ZD , 1000mfd 100v c2,and 100r 5watt r2, 470k r1 i/2 watt,

    27. Thanks a lot !
      Its simply gr8 circuit !

    28. sir its a wonderful circuit…. i will surely try it…. thnkx for posting such a great circuit…

    29. sir, i want to connect 16 & 24 leds of 8mm 3.5v 100ma what r d changes should i do in the circuit.

    30. dear,

      can u give the circuit of led street lights , led power tube light. kindly
      reply me

    31. dear sir,
      kindly can u give the circuit diagram & details of led street light & led power tube light.sir kindly please give the reply

    32. Dear Mohan kumar,
      Can i make an 220V ac operated LED lights as replacement for my 6OW incandescent bulbs by using 100-120pcs of smd LED’s in 60 in series x2 parallel strings.Each led Vf 3.2V, If 20mA ,reverse voltage 5V.
      Suggest a suitable circuit which can take care of voltage fluctuations in our country and also have a good power factor

    33. I would like to share my experience. I have used 8mm LEDs (25 of them in series) Only used resistance of 4.7K Ohms on the line going towards rectification diodes and rectifying diodes and it worked like a charm then I googled for further information and found this website. I did not use caps only one for removing ripples, if any.

      • Chinmoy Mitra says: on January 17, 2012 at 12:21 pm

        Dear Naeem, it seems to be very smart of you to use just a 4.7K resistor to limit the current in the LED’s, but a little bit of calculations will show that the power dissipated in the resistor is about 5.1 Watts! So you shall require a 4.7K/10 Watt resistor. You have not mentioned the wattage of the resistor used.
        Secondly, dissipating 5 watts of power is not a wise thing to do, since it will produce a lot of heat.
        Calculation for power:
        Power (watt) = VxV/R
        V = Voltage across the resistor
        R = Resistance in Ohm
        The total voltage across the LED’s can be calculated by multiplying the number of LED with 3 (because each white LED will drop about 3V), which comes to 25X3=75V
        That leaves 155V across the resistor.

    34. Dear Sir,
      What type of LEDs do you recommend for this ckt.
      Straw hat LEDs or the conventional Hemisphere (convex) LEDs or SMD LEDs.
      Please reply as I am very eager to assemble this ckt

    35. Dear Mohan kumar,
      I am an amateur and would like to do my bit to save electricity.I wish to replace all 60W bulbs with suitable LED bulbs comprising 100-120pcs of LED’s used in 60 x2 configuration (60 in series string and two parallel strings)Each led Vf 3.2V, If 20mA ,reverse voltage 5V.I requested for your help earlier but it seems you are busy as i have not seen your messages.
      I once again request you to Suggest a suitable circuit which has a good power factor

    36. What is the perpose of Choke in tube light

    37. dear mohan sir,

      i do the above ckt with cx as 105k250volts and c2 capacitor value 1000uf 63 volts with zener doide value 69v but1/2 watt 1watt zener and 105k400volts not available chennai market.but all 25 leds are glowing with low brightness all leds are connected in parallel.before i connected in series nothing glow.then i changed in to parallel.with out load i get out put 6volts with load measuring 2.6 volts amps 200ma only.what is the maximum voltage and current at the out put should be there for better brightness for 25leds 5mm. pls help me my email..matheew30@yahoo.com

      i bought 5sets of components for 5 ckts. now i dont know wat to do. pls help me

    38. sir
      if i change cx 105k250v to 105k400r600 my problem slove r too change c2 and zener

      thanks in advance

    39. mr.mohankumar so many pepole asked question.still u r not giving solution.in power led 1watt ckt i done alljobs correct but it glow very very low.i dont know wat to do pls help me

    40. is there any substitute for polyster capacitor?

    41. Antonie Solomon says: on April 21, 2012 at 3:31 am

      Hello, I’m not an electrical enginer but since mr. Mohankumar is bizzy I will try to give the best advice.

      The polyester type is a common capacitor, you don’t need any substitution. It is important to use a non-polarized capacitor, a polarized [electrolityc] will not work for C1. Also the voltage marked on the cap must be at least 400v preferable is 630v or more.

      The capacity indicated in the schematic is mistaken; at 2,2 microfarads [225k] the current absorbed will be 0.2 A burning the zener and at least one LED.

      The capacity of 1 microfarad [105k] will produce 100 ma wich is suitable for big 10 mm LEDs [skip the zener in this variant].

      For normal 5 mm LEDs use a C1of 0.22 microfarads [224k] for a current of 20 ma.

      About the value and voltage of filtering cap C2, the role of this is only to reduce flicker, so 1000 micro is overkill, any value between 2.2 and 22 micro wil be enough. Is better to use a 350V cap, as it can acidentaly charge directly from the mains. Good caps for C1&2 can be foud in old burnt CFL lamps.

      The zener must be at least 1w in power, if 1w is not available use 2 pieces of 33 [36] Volts / 0.5 W in series. Make shure you connect them properly with the cathode [-] to the positive V+ [ reversed conduction] , if direct conduction is applied they burn out.

      The zener diode is protecting the LEDs against power surges in the electric grid, it can be replaced with a 10k/0.5W resistor if your power voltage is normal 220v.

      Pay attention to correct polarity of LEDs, the LEDs will only light in direct conduction, if only one LED is reversed no current will pass.

      I believe resistor R2 wil work at any value between 100 – 330 ohms/0.5 W. To simplify even further you can skip D1, D3, D4 and use only D2 as mono rectifier. In this case connect R2 directly to C2 cathode/D25 LED.

      • Hi Antonie,

        It’s been over two years since you provided your understanding of this circuit. Just wonder if you have gained more knowledge since then to correct the few misconceptions.

        There are discrepancies in the values of current supplied by different values of C1. Even the zener is skipped and only one LED is connected, the currents supplied by a 2.2uF, 1uF and 0.22uF C1 are roughly 150mA, 70mA and 15mA respectively.

        In this circuit, the output voltage has been regulated to 69V by the zener. Even without the zener, the 20 white LEDs will still drop the input voltage by roughly the same amount. The result is the DC output currents will decrease to roughly 105mA, 48mA and 10.5mA respectively. The current figures you provided have discrepancies.

        As regard to connecting two 0.5W zener diodes in series, the power tolerance is still 0.5W.

        Lastly, you mentioned about the possibility of only connecting one rectifying diode. This is a big mistake and the circuit will not work at all. The reason is that as soon as C1 has been charged, D2 will block C1 from discharging as D2 conducts in one direction only, and there won’t be any current flow in the circuit. In case half-wave rectification is preferred, reverse the postion of the zener and C2, then connect D2 in series inbetween the two. Since the zener is bi-directional, C1 is able to perform the charge / discharge cycle sequentially. Of course, available current would roughly reduce to half.

        The circuit will work even without the zener and C2. The inclusion of both is a preferred option, with C2 connected in parallel inbetween the zener and the LED string. The zener will make sure 69V is always applying to the LED string, and C2 will guarantee a steady current flow through the LED string. Without C2, the LED string is getting pulsating sine-wave DC current.

    42. sir, can i use IN4007 in the bridge rectifier.

    43. can i use normal 5mm led for this circuit

    44. Dear Sir

      Please give me good configuration for 100 LED lamp


      • Kalikaprasad Mukherjee says: on June 1, 2012 at 1:49 am

        Dear sir,I want to use your circuit to operate 3.2V,100mA white led connected in series.What changes are required?Thanks

    45. as per the configuration,tere is no need of step down transformer?

    46. Hello Mr.Mohan,

      I feel there are some missing info in the circuits component.For ex:
      1) C1 has mentioned 225k 400v, but is the 400v is an AC/DC? I hope it’s AC right? and what about tolerance value?
      Is it polyester type (plastic film) or something else? can you provide some part no. of the capacitor?

      2)Resistor: Is it of NT/PTC type? Is it thermistor? at what sensitive temperature? Thermal Coefficient? thermal time constant? Sensitivity Index?

      3) similar kind of information for other components.

      I’m a kind of green environment liker. So I’m eager to try this circuit and implement it for my house. Pls provide me with necessary support.

      If anyone have detailed information for the above components, pls let me know.

    47. A.M.MAHVY,MUMBAI. says: on May 21, 2012 at 9:59 pm


    48. sir,

      is there any alternative for 225k ,400v capacitor,as it is not available in my locality.

    49. Kalikaprasad Mukherjee says: on June 1, 2012 at 2:02 am

      Der sir,It is a very simple circuit.If required to connect 3.2V,100mA led some changes are required I think,perticularly the watage of the resistors.What is you opinion?Thanks

    50. Dear Sir,
      i’m very new in this sector but i’m interested to electronics. pls send me the 5mm LED light A/C disgrsm which is equvalent of 26w CFL or 40 watt tube light.

    51. sir how we perform a suitable ckt ple help me

    52. please any one cn tell me that LED cricuit has connection in series . if any LED get short or fuse. that waht will happened with all other LED lights.

    53. sir
      please tell me can i use 100uf 100v for c2

    54. C2 from safety point of view suggested should be rated at 250V( For 240V supply)
      The bleed resistor R1 we recommend you use 1M this would reduce the need of the Zener and also you could add 28 LED’s in series

      R1 as 470K is used with 474 x-rated capacitor. The resisotr here even if its 2W will burn with time.

      the R2 100E should be a FSR.

    55. We have successfully used the following
      R1 = 1M/1/2W in lieu of 470k
      C1 = 225 X-Rated/630V in lieu of 225/400
      R2 = 100E FSR in lieu of 100E
      c2 = 10ufd/250V in lieu of 1000u/100V

      We have not used the zener in our circuit.
      We have 55 LEDs in series.

      • Aditya Shrivastava says: on September 19, 2013 at 9:29 am

        sir,,plzz tell me..had u used a bleeding resistor??
        and..what does FSR means??..and what is the difference between 225 X-rated and 225k regarding capacitor,as u told…..Thanks..waiting 4 ur reply..

      • Hiee Sebastian Kushero will you please send me the circuit diagram of your project if possible.
        Thank u.

      • jayesh patel says: on January 25, 2014 at 10:07 pm

        Dear Sebastian,
        Please give white LED size you use ie, 5mm /20mA or 8mm/100mA.


    56. @Happy, Min voltage rating for C2 is 100VDC.

      • i know but 1000uf 100v is not avaliavble here . also i try 560uf 100v ,470uf 100v
        there also not avaliable what to do .
        xener diode 69 also not avaliable 100v avaliable ,oe 35v

      • Jim Keith says: on July 30, 2012 at 1:47 pm

        560uF 100V should work OK. (2) 35V zener diodes in series should work OK. Take care as this circuit presents shock hazard.

    57. I have certain queries. Can anyone help?(1)The costliest part in the circuit is the capacitor 1000mf/100V. How is the Capacitor volatge value decided? Can it be changed so as to reduce the cost?(2) Further If we touch the parts after rectification will it give a shock?
      Thanks in advance

      • Jim Keith says: on August 1, 2012 at 1:30 pm

        The capacitor voltage is determined by the total LED voltage drop:
        20 LEDs * 3.4V/LED = 68V (approximately)

        Should it be slightly higher in voltage, the 69V zener conducts some of the current.

        Therefore, the minimum capacitor voltage rating is 100V as there are no other common voltage ratings that will suffice. For max capacitor life, additional voltage is recommended.

        Touching the circuit at any point will not provide an electrical shock unless your body is otherwise grounded–e.g. standing barefoot on an earthen or concrete floor, or touching a metal water pipe with the other hand etc. If the fault current exceeds about 30mA (less for women), you may not be able to open your hand to let go of the conductor. For that reason, the circuitry must be fully enclosed in a plastic box or grounded metallic enclosure. Death from electrocution is uncommon as we have all had shocks and lived to tell about it–however, take care.

      • Transformerless Power supply are strictly for the experienced and CAUTION MUST BE EXERCISED

        REGARDS THE CAP VALUE Referring to Keith who is right

        It must be 2* Voltage
        If you need for 20 LED’s the characteristic voltage is 3.2V to 3.6V taking the higher rating of 3.6

        3.6*20*2 = 144V ( may not be available buT you may get 150V. The voltage of the capacitor is critical and being on the hoigher side is being on the safer side capacitors burst.

        As the negative rail is live and the voltage on this would be 110V WITHOUT LOAD to be absolutely safe you should think of around 250V V capacitor and lower its value anything from 22ufd to 220ufd

        IT you are making this circuit (PLEASE) enclose it in a insulated cover and do not touch (ANY) lead as the capacitor does NOT discharge completely and you would be in for a rude jolt.

        If you can get a cover of any old battery charger enclose the circuit in it or if you are a beginner you would be better off use a transformer of 12V /200 Ohm rating use a bridge and use a 220ufd/40V for obtaining pure Dc and string three leds in a series and use as many strings as you may need. but remember that you would have to have a current limiting resistor at the end of each string (3 LED’s + resistor preferable 47E this value can differ from 22E brighter tp 100E not so bright) The resistor are used to protect the LEDs from current surge and will prolong the life of the LEDS.

        Send your email for circuit and PCB design using a wall transformer

      • Sir,
        I want to make light of 20 LED(8mm)So plz send me the Circuit diagram

      • What is your mains voltage (120V, 220V or 230V) and the specification of the LED used (voltage drop and forward current)?

    58. Dear Sir,
      what is transformer output voltage (secondary) and current rating pl

    59. for the same circuit what value should be given for capacitor and resistor for 60 blue led.

      plz reply

    60. dear sir,
      how do you calculate the value and type of Capacitors and resisters for a circuit…………….

    61. sir i have problem , i have zener with 68 ,is that compatible with all dat ?
      2nd 1000uf 100v is ther any replacement of this c2 Capacitors ? bcoz here not avalable :(
      plz can some 1 help ?

    62. Dear Mr. D.Mohankumar,

      i want ask you…..how can i design the AC to DC converter Driver circuit for LED Lighting…… that i need to add DC to DC converter to connect with LED or Direct from ac/dc to connect with LED??

    63. Dear Sir,
      thank you I tested this circuit…it is wonderful…I have some Qs…?

      01.I wanna know how much consume these LED lamp. (Max Watts ?)
      02. If i use more LED for this circuit what should i change of theses tools..?

    64. Please Suggest me circuit,Using

      7W/6500K ,4Pin DC CFL Bulb

      Please reply. Thank You.

    65. can you send me a equivalent circuit operating with led having equivalent power as 45 watt CFL.also give me some tips

    66. sir
      explain this circuit power calculation.
      how many watts taken for this circuit?

      • Jim Keith says: on December 9, 2012 at 7:46 pm

        The True Power in is very close to the total series LED voltage * LED DC current.

        The power factor is leading due to the effect of the series limiting capacitor, so the Apparent Power (EACin * IACin) will be higher than the true power.

        I do not have a good understanding of LED luminous efficiency, so I cannot guess luminous power out. Simply note that LEDs have conduction losses so they dissipate power when operating. At 100% efficiency, there would be no heat generated.

        Interesting article:

    67. Great project sir!I like the compact design very much and is planning to make such a setup using 24 leds and replacing the 69 volts zener diode with a 75 volts,so that each led will get app.3.125 volts.But I don’t like to have leds in series because its gonna be such a mess if the system fails and I’ll have to test all the leds to find the faulty one and then replace it…..I was wondering if I could use a 3 volts zener diode instead so as to connect all the LED’s in parallel?

      • Good idea except that 3V zeners are very sloppy and have an indefinite knee –will steal current from your LEDs. My recommendation is that you make a simple LED tester with a 3V battery and some resistors –I use mine frequently. Will post an LED tester shortly.

      • Dear Adarsh_tronix, you cannot use a 3V zener diode in this circuit.
        1. Zener diodes can only operate successfully when they conduct more current than the actual load. The current is usually 2 to 10 times the load current, and this is to ensure that the zener diode actually regulates the output voltage. Assuming a 20 mA curent per LED, the total current for 24 LED’s comes to 480 mA, and to regulate that kind of current the zener current should be at least 2X480 mA, which is 960 mA! I have not heard of any zener diode which can pass that much current.
        2. LED’s cannot be simply connected in parallel because of the differences in forward voltage drops and dynamic resistance of individual LED’s. So an LED which has a lower forward drop will conduct more current and will shine brighter. In fact, some of the LED’s with higher forward drop may not light up at all. To connect LED’s in parallel, you must add a current limiting resistor in series with each individual LED; so that means a total of 24 resistors must be used.
        3. Even if you do not use a zener diode, a current of 480 mA cannot be provided by this simple power supply. This type of capacitor based AC power supplies are meant for very small current devices of the order of 30-40 mA max.
        I hope I have been able to answer your question.

      • Adarsh_tronix says: on February 2, 2013 at 5:16 pm

        Thank you Jim Keith and C.Mitra for your valuable suggestions and Mitra yes,you have been able to answer my question.I’m new to electroschematics.com and just love the way things are set here.Expecting more such help from you folks;

    68. Daer Sir,

      Please give me circiut diagram for 100/120 LED lamp

    69. Hi,
      Thank for this circuit.. Can You Say how I add This circuit to 80 bulbs this circuit,,

    70. Dear Sir,
      I didn’t understand one thing. As fer I know C1
      474K can supply 12v 25 mA
      105K can supply 24V 40 mA
      225k can supply 24v 100mA
      I got that from http://www.electroschematics.com/5678/capacitor-power-supply/)So how could it possible lightning 20 led in series that have 20×3.2=64v needed??
      On the other hand I got another same circuit in this site (http://www.electroschematics.com/3752/transformer-less-power-supply/) is 12v 100mA.
      Please sir explain it to me.

    71. Dear Sir,
      I didn’t understand one thing. As fer I know C1
      474K can supply 12v 25 mA
      105K can supply 24V 40 mA
      225k can supply 24v 100mA
      I got that from http://www.electroschematics.com/5678/capacitor-power-supply/)So how could it possible lightning 20 led in series that have 20×3.2=64v needed??
      On the other hand I got another same circuit in this site (http://www.electroschematics.com/3752/transformer-less-power-supply/) is 12v 100mA.
      Please sir explain it to me.

    72. sir,

      what will be output dc voltage at NO load without zener diode.can be measure by multimeter.

      • With no load, no zener, and assuming that the capacitor has adequate voltage rating, the DC output voltage approaches the peak-to-peak voltage of the AC line voltage. About 620V

    73. Can I add 73 leds in series and remove zener diode. So total voltage is 73*3=219v. Is there some technical hindrance to it?

    74. sir,
      can you send me such ckt diagram for high wattage like
      250w or 500w , by using 5w power LEDs.& give also some tips for that.
      ckt. “I will thankfull for this help “.

    75. I would appreciate to be on your email list.
      To subscribe to your suggestions and so forth.

    76. I really like what I read on this site. Keep up the excellent work.

      JG MIRON

    77. can you send me a equivalent circuit operating with led having equivalent power as 25 watt CFL.also give me some tips
      for spreading the light through out the room instead of directing to one side.

    78. dear sir .. i need circuit diagram for 8mm,0.5w straw hat (10 to 15 led’s) input 230vac

    79. Dear Sir….Meany Meany Thanks This Circuit….

    80. Dear Sir,

      From which calculation can I calculate the value of resistance R1 R2 & C1.

    81. Dear All members,
      The circuit give here is a very practical LED lamp circuit. It is the most commonly used circuit today for powering all kinds of low current devices, especially LED’s. I have one word of caution regarding the use of this circuit for LED lighting purposes. This circuit is quite sensitive to the incoming mains voltage. White LED’s are also sensitive to voltage and current, a slight increase in the current can be catastrophic and quickly lead to the destruction of the LED. Please do not use this circuit with cheap power inverters at home, since these inveters have very bad voltage regulation, and sometimes the output voltage can go upto 260V AC with low loads. Chinese LED bulbs widely use these circuits, and I have lost a number of these bulbs while using on inverter power.
      The zener diode in this circuit may provide some amount of protection, but it is not recommended to use zener diode in this manner since it may get quite hot and waste a lot of power.
      Any views contrary to mine is welcome…

    82. nitesh majumdar says: on April 28, 2015 at 5:15 am

      sir can u tell me… if i wll use a 20w cfl circuit than howmany 3v leds can use… or if i want to assamble 1w led… than what can be change on circuit….

    83. Sir would you please help me to make a rectifier circuit containing 5 led’s

    84. Sir…
      Can i replace c1 with other capacitor?
      When replace it than which voltage and value capacitor use..

    85. Sir, can i use 6 and 10 no. 0.25w led in this curcuit? And what should be change in curcuit for this?

    86. Dear Sir,
      I didn’t understand one thing. As fer I know C1
      474K can supply 12v 25 mA
      105K can supply 24V 40 mA
      225k can supply 24v 100mA
      I got that from http://www.electroschematics.com/5678/capacitor-power-supply/)So how could it possible lightning 20 led in series that have 20×3.2=64v needed??
      On the other hand I got another same circuit in this site (http://www.electroschematics.com/3752/transformer-less-power-supply/) is 12v 100mA.
      Please sir explain it to me.

    87. Can I Use 3 Or 4 Zener In series?Plz Help me as soon as possible.

    88. Can i Use 4 or 5 Zener in series,and can i use 1000 uf 160V Capacitor.

    89. Listin Augustine says: on December 20, 2015 at 6:55 pm

      Hi sir, can i use this same circuit to power 10 numbers of 2 watt smd led or is there any changes to be made. Pls help me by giving me a reply at my mail id listinaugustine@icloud.com . Your help will be greatly appreciated. Thank you.

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