The PCB is the standard XL4015 CC/CV board; usually it has 2 pots and 3 LEDs and sold as a li-ion charger, but there is a variant with just 2 pots. I've been using it to charge batteries and as a general lab supply for low current stuff. It's tiny, even with the displays, but I knew it was only a matter of time before some crap on the bench shorted it out, or wires fell off.
I use it with an old 18V/5A laptop supply which is way in excess of the output power, put it means I can get to 14V ok for charging.
I didn't need the LEDs, so I removed them and re-used the spare 1/2 of the LM358 to make a x20 DC amp for the current display.
The chip is good for 5A, but the op-amp isn't rail to rail, so current limit wont go much beyond 4.5A; the display won't read above 3.7A. This would be an easy fix using something like LMV358. Wish I'd spotted that before removing it to modify the pcb.
I got instability on the output as the main cap is before the shunt (on the -ve rail) A 100/25 fixed this, but means the output is now limited to 25V.
There is a biased switch to allow the current limit to be easily set, rather than starting high and winding the limit down. Going the other way won't allow most gear to actually start.
The chip is quite efficient - say 80-90%, but it does run warm with a high input to ouput volts ratio with a few amps. A copper tab was soldered on to the regulator to get the heat to the case. Don't be temped to put on a heatsink; it would do very little in such a large volume and fail to convect.
The case is 80 x 55 x 25. It's a bit tight and you can see the input terminals have gone and 1 cap is on its side, out of the way. The displays are just the cheapo 70p ones off ebay, modified to improve accuracy - see other blog posts, hot glued in place. I'd have preferred to mount them under a clear window, but I already had the box.
