“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 ...

By building his power supply in a tin, [Helge] keeps to his compact build philosophy. But the circuit is all solid state, which is an interesting departure for him. The switch-mode supply uses a ...

The common type of power supply used with computers and other electronic equipment. The "switching" comes from switching a transistor on and off to create square waves for input to a transformer.