LED Battens Drivers

[Peter Cook 6Participant @petercook6]

I recently bought some fairly cheap Chinese made 6ft 60W LED battens to replace the fluorescents in the workshop.

Two failed (one DOA – transit damage – and one shortly after installing). Both were replaced without quibble under warranty.

I decided to open the failed units (they did not want them back) and see if there was anything useful inside (as you do!). One had failed due to a badly soldered wire – very quick fix. The other had a blown chip – magic smoke had come out. They are interesting in design. They have two 3ft strips each with two rows of 75 LED's end to end. Driver electronics for each strip are in the ends, and mains voltage is carried from end to end down tracks on the strips.

 

The strips looked useful if I could obtain replacement drivers. So I measured the DC voltage used by the strips in one of the working units. 420V+ !!!

Presumably the 150 LED's in each strip are in series and the drive electronics supplies 70ma from full wave rectified mains voltage.

Anyone seen a source of (cheap) LED drivers that push out 400+volts?

Edited By Peter Cook 6 on 31/01/2023 15:10:35

[Peter Cook 6Participant @petercook6]

High Voltage Units?

[bernard towersParticipant @bernardtowers37738]

400 volts and LEDs surely not!

[Ian PParticipant @ianp]

Posted by bernard towers on 31/01/2023 15:35:09:

400 volts and LEDs surely not!

Why not?

They are arrays of individual LEDs each operating off low voltage, low current but connected in an array.

Ian P

[BazyleParticipant @bazyle]

While inevitable that all the LEDs are in series it does present a reliability nightmare as every single one failing brings the whole unit down, even though this case was the chip.

You might look around for for scrap floodlights. I picked one out of a skip for the aluminium housing but the reason for failure was the square LED array not the psu. Since the array on it's own was more than the whole assembly it was BER. I couldn't think of a use for the psu as it was fully encapsulated so too difficult to get to the bits to make it adjustable for any other use.

[Sonic EscapeParticipant @sonicescape38234]

It looks like it is possible to change the strip configuration. By desoldering an LED maybe. Then you could divide the 420V strip in two. If the two resulted strips are connected in anti parallel you can connect them directly to 230AC. With only one good quality film capacitor in series to limit the current. A value between 10-15μF should cause the necessary voltage drop at 70mA.

Of course such a circuit will not be safe to touch in any point. And maybe could cause some 50Hz flickering. But in the absence of other options, it is worth trying

Edited By Sonic Escape on 12/02/2023 21:49:54

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