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Power LED

Power LED Lamp

Here is a High power White LED lamp circuit that gives ample light in a room. It is an energy saving lamp and consumes very little power to give sufficient light. The lamp is directly powered from AC hence it is compact and easy to fix inside the switch board box.

The Power LED Lamp circuit uses 1 Watt White LED as the light source. Luxeon type high watt LEDs are now available. It is rated 3.6 volts and consumes maximum 350 milli amperes current. To get sufficient brightness of the LED, more than 200 mA current is required. The AC power is dropped by three 105K (1uF) AC capacitors to low voltage AC. Three capacitors (C1through C3) are connected in parallel to increase current so around 210 mA current will be available.

The low volt AC is then rectified by the bridge comprising D1 through D4 and made ripple free by C4. Since the LED voltage is 3.6 V, Zener diode is used to regulate the DC to a safer level. Capacitor C5 act as a buffer to store current to give maximum brightness to the LED. Resistor R1 removes stored current from the AC capacitors when the circuit is unplugged and resistor R2 protects the circuit from transients and inrush current.

Power LED Lamp Circuit diagram

Power LED Lamp Circuit diagram

1 Watt Power LED

Caution: It is important to note that this circuit can give a lethal shock if handled carelessly. Most points are at mains potential, so that take utmost care while handling. Do not construct this if you are not experienced in handling AC circuits. Do not troubleshoot or test when it is connected to mains.

65 Comments

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  • ajay

    Dear Sir ,

    i would like to build 9 LEDs in Series ( 60 to 140 ma current ) in 220v AC mains , could you help me to modify it.

    Thanks
    ajay

  • shibu

    hi i need a circute for car when we lock the car, headlight should light for 30sec and when i unlock also the same should happen and it should happen only when there is low light is it possible ?

  • Dileep

    if Zener fails in above circuit how much current is flow to led?
    And another question is R2 and R3 resistors are heating very much. what is the solution for that?

  • Jaspreet

    Can anyone kindly explain how to arrive at value of R3.

    • John Lam

      In a transformer power supply, R3 acts as a current limiting resistor to protect the zener from operating above its rated power. In a capacitive power supply, current is determined by the voltage of the load and the total impedance of R1, R2, C1, C2 and C3, and the inclusion of R3 is redundant and should be removed.

      This circuit will roughly deliver 200mA current. Depending on the specification of the LED chosen, a 1W white LED will consume 285mA current at an applied voltage of 3.5V. That means the LED in this circuit will actually consume all the available 200mA current, leaving apparently no current for the zener that in fact not conducting at all. The zener diode is needed to bypass the surplus current only if the current supplied by the circuit is more than the white LED can consume. In short, the zener diode is also unnecessary in this particular circuit. If ZD is removed, C4, C5 and R4 can be removed as well. In this case, the LED is runnung under pulsating sine-wave DC current; and steady DC current is preferred for lighting LED.

      To keep the same circuit (R3 should be removed) so that the LED will operate under a steadier DC current, the combined value of C1-C3 must be big enough to supply an average current greater than 285mA. Connect two 2.2uF 400V (or higher) metallized film capacitors in place of C1-C3, the circuit is LIKELY to operate as designed. Change the value of the zener and/or adjust the value of R4 to match the specification of the LED used.

      Example 1: If the LED used is 1W @3.5V (286mA), and zener is 4.7V as shown in the circuit, R4 = (4.7 – 3.5) /0.286 = 4.2Ω.

      Example 1: If the LED used is 1W @3.3V (303mA), and zener is 4.7V as shown in the circuit, R4 = (4.7 – 3.3) /0.303 = 4.62Ω.

      Pick a resistor as close to the calculated value as possible.

      Example 3: Same LED as in example 1, and 3.5V zener used. R4 is not necessary.

  • dolamani bhoi

    sir ji 1 watt ya 3watt power led transformerless circuits mere ko send kar dijiye

  • reza

    Thanks to all
    please help me for design circuit led power supply 150w 12v 12.5 A

  • stiv

    I tride to follow the circuit diagram but i’m getting 220V after the rectifier … where could be the problem?

    • Jaspreet

      I do not think there is any problem. The C1 capacitor in series gives constant current because of its high reactance. Without load these non isolating circuits will have almost same vout as vin. Thats why they are dangerous and care should be taken while working with them.

  • S.Shanmugam

    As some people stated above, I am also interested in making LED light which can replace 40W Flourescent Tube, 220volt input with equal brightness. Can someone please email the circuit to me.
    Thank you in Advance

  • S.Shanmugam

    Thanks to all
    As some people stated above, I am also interested in making LED light which can replace 40W Flourescent Tube, 220volt input with equal brightness simple circuit as above. Can someone please email the circuit to me.
    Thank you in Advance pl mail me on srishan.eee@gmail.com

  • amson

    Dear mr mohan kumar

    could you please send me 3w (equal to 40w bulb brightness) 6w (equal to 60w bulb brightness) and 9w {equal to 100w bulb brightness) or any equivalent and simple as your above circuit to my mail Id amsonoflord@gmail.com Thank you amson oflord

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