This simple 1 watt LED lamp can give light equal to 11 watt CFL. It is directly powered from AC using capacitor power supply. The light from this 30 LED lamp can very well illuminate the room and is suitable for reading purpose also.

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Capacitor powewr supply uses 474 J AC capacitor and standard full wave rectifier comprising diodes D1 through D4.C2 act as the filter capacitor. R1 is the bleeder resistor to discharge capacitor C1 at power off. 30 High bright White LEDs are connected in series with current limiting resistor R2.

LEDs used in the circuit are not the ordinary type but high bright white LEDs.

Circuit enclosed in an Old CFL case

High bright Flood light LEDs

New versions of low current high bright LEDs are now used to make home lighting. These LED lamps can replace CFLs and Tube lights and consume only 1.5-2.4 watts compared to the 36-40 Watts of CFL or Tube light. These LED lamps can give 50,000 hours light without fail. Luminance range from 10,000 – 18000 MCD and the operating temperature is from -40 to + 95 degree. Current consumption range from 40 mA to 100 mA in various makes. Input voltage may be 2.8 to 3.5 volts.

For part number and types see these links

Caution: Shock Hazard. The circuit is directly connected to high volt AC and there is the risk of shock if handled carelessly. Do not touch any points of the circuit, when it is connected to mains. Do not construct this circuit, if you are not experienced in handling high volt AC.

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About D.Mohankumar

D. Mohan Kumar M.Sc., M.Phil, is an Associate Professor from Trivandrum, Kerala, India. He has been guiding Post Graduate students in Animal Science research for the last 25 years in several premier institutions in Kerala, India. He is an avid electronics enthusiast and has been designing circuits for the past 20 years. In this period he has supported many electronics/electrical engineering students in their final year projects. He is a regular contributor to Electronics For You magazine which is South Asia’s largest circulating electronics magazine published from New Delhi. He is also contributing articles in and

5 responses

  1. A.M.MAHVY says:


  2. vhhp says:

    Unlike any electronic component- the LEDs are not indicated with any number. How to find out what sort of LED is it and to know the charcteristics, please show the experimental setup to calculate the properties of a LED, hope for most of the students also it is useful.

    • D.Mohankumar says:

      New versions china make LEDs are now available and we can select the required type referring the data sheet. Usually the high bright LEDs used in torch light are used in LED lamps. They operate in 2.8-3 volts and consume 40-100 mA current

  3. yogesh says:

    please specify led 1 and other 30 leds details