• 12 years ago
How to make a mains operated LED lamp with 19 white LED's.

Perfect recycling here !!

Old B22 base used from a discarded compact fluorescent lamp, old parts removed, resistors, bridge rectifier and LED's fitted. Hotglue gun to put circle and base together.
Electrical tests and measurements done and video clip made to share with the rest of the world.
Voltage: 240 Volts
Current: 16 milli Ampères

Materials used:

5 x Resistors, 1 Watt carbon 2k2 ohms
4 x 1N4007 diodes
19 x 5 mm Ø white LED's 12000 MCAD
1 x old B22 base
1 x circle cut from PVC or perspex (cut with holesaw)

Basic principle behind the lamp 240 Volts - 57 Volts for the 19 LED's requires a 11 k.Ohm series resistor of about 2.8 Watts.
For better cooling I prefer to use 5 x 2k2 ohm 1 Watt resistors in series to give me a good safety margin.
The bridge rectifier reduces flicker of the LED's. 100 Hz in my case, 120 Hz with American frequencies.

For use on 110 or 127 Volts systems I recommend to use 4 x 1k5 ohm 1 Watt resistors in series.

Safety !!

Working with mains voltages requires safe work practises, unplug before touching.
Check that the resistors are not too hot and rather over rate then under rate them.

Category

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Learning