adding a "power output button" to a cheap bench power supply
If you can figure out the internals of your power supply, adding a relay and a momentary push-button is a fairly simple task, perhaps with an added LED for feedback. (Or an illuminated momentary push button I guess.)







simulate this circuit &ndash; Schematic created using CircuitLab

Once it's on it would stay on till you turn off the supply though, but you can add a second, normally closed button to disconnect.