Modifying Lights to LED

[nigelmercier]

This is more drain than the Fluorescent tubes so some sort of regulation is required.

Why not just remove a string of LEDs? They will be brighter without the regulator.

 

[LadyInBed]

Why not just remove a string of LEDs? They will be brighter without the regulator.

Good thought! didn't test the 3 or 2 strip units without the regs.
I've ordered the regs and caps now
Ha Ho, all good research.

 

[LadyInBed]

Here are the numbers:
I/P to Light Unit before Reg = 12.7v
O/P from Reg = 10.6v

4 strips of 15 draws 452mA call it 450
3 strips of 15 draws 398mA on one light and 415mA on the other, call it 400
2 strips of 15 draws 295mA call it 300
I'm not sure why it isn't linear, maybe switch resistance and component tolerance?

Compared to Fluorescent 2 tube unit which draws 715mA

I've now put the LM2940-12 and capacitors in which has bumped up the O/P Voltage and the lights brightness so here are the new numbers:

I/P to Light Unit before Reg = 12.6v
O/P from Reg = 11.9v

4 strips of 15 draws 941mA call it 940
3 strips of 15 draws 700mA on one light and 616mA on the other, call it 650
2 strips of 15 draws 456mA call it 460
So with 3 strips it is about the same drain as the Fluorescents
4 strips is nearly an amp
The only saving on current is when using 2 strips, unfortunately I can't now check the brightness of 2 strips of LED's against the Fluorescents!