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Saturday 31 December 2011

power saving

Power saving LED lamp from your scrap box


This is just a LED lamp circuit that can be operated from the mains voltage. A string of five LED is driven using a capacitive transformer less power supply. In the circuit 0.47uF/400V Polyester capacitor C1 reduces the mains voltage. R1 is a bleeder resistor which drains the stored charge from C1 when the AC input is switched OFF. Resistors R2 and R3 limits the inrush of current when the circuit is switched ON. Diodes D1 to D4 forms a bridge rectifier that rectifies the reduced AC voltage and C2 acts as a filter capacitor. Finally Zener diode D1 provides regulation and the LEDs are driven.
Photos.
LED lampfromscrap
CFL lamp


finished lamp
lamp glowing
LED arrangement


LED PCB back
PCB
PCB closeup

circuit daigram:




about the circuit:

I am sending you a table lamp made from defunct energy saver lamp with broken tubes. CFL converted into LED lamp. Most of the components will be available in ones scrap box. Few components available in the CFL PCB also can be used.


Procedure :


1. Carefully remove the broken glasses
2. Open the assembly carefully
3. Remove electronics and discard
4. Assemble the circuit in dot matrix PC or on a 1mm laminate sheet.
5. Cut a round laminate sheet with (scissor)
6. Mark the position of the 6 round holes on the sheet
7. Drill the holes to suit the LEDs to flush fit in the six holes
8. Use a dab of adhesive to keep the LED assembly in position
9. Close the assembly
10. Ensure the internal wiring does not touch each other
11. Now test on 230Volt AC
Your nice compact table lamp / puja room lamp / passage lamp is ready for use.