Cousins bench lamp power supply

teegee · March 31, 2020

I've just moved house, and of the hundreds of items in the workshop it seems the power supply for my Cousins' LED desk lamp has gone missing. This one, discussed here before.

Could anyone with the same lamp tell me what the power supply looks like? Colour, type (wall-wart or in-line?), and specs, in case I have to replace it.

Before realizing that I was using a 12V supply that was actually for my watch timer, I was already debugging the thing with my oscilloscope. I wasn't able to find anything wrong using a benchtop PSU at 18V, *except* for the main diode (that feeds the MCU via a 7805) being the wrong way around. My electronics education from 25 years ago is failing me in explaining how this could ever have worked in the first place, lol.

teegee · April 5, 2020

Oddly enough, no responses -- even thought this particular light was actively discussed a few year back.

Anyway, it seems a 20V standard power brick is about right for now, but it could be 22V or 24V as well. I'm waiting on Cousins for the actual specs.

The diode issue was obvious; it's a zener (I was convinced it was just a regular power diode).

I've drawn up a schematic for future reference, and attached it here in case someone is interested. They sanded the ID off of the 8-pin MCU, but there's only so many 8-pin MCUs. I made an educated guess, having used that particular pic12 before.

led-bench-light.pdf