I needed a Constant Current power supply for my bench. Now I don’t know if you have priced bench power supplies lately, but they can be several hundred dollars. Not any more! Would you believe a 40v 3a adjustable voltage or current supply for about $20?
https://amzn.to/2MNnOcc
I grabbed a used 24vac HVAC transformer, soldered a bridge rectifier on top, and fed the input on this board. I put a 300ma 1w LED on the output, and I’m controlling the brightness by controlling the current, even down to 2ma (dim), all the way up to 300ma (blindingly bright). I could go higher, up to 3000ma, but that will let the magic smoke out.
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