Adding off-load constant current setting. Replacing the front panel push-button switch with a 555 chip ... Single variable output 0-30VDC 0-3A Bench Power Supply #CSI3003X-5 Single variable ...

“They don’t build ’em like they used to.” There’s plenty of truth to that old saw, especially when a switch-mode power supply from the 1940s still works with its original part ...