If you put an IO with a 120 second timer in an auto power they're on all the time. If you put it in a click or toggle power it will last for 120 seconds after the power is deactivated.
Global IOs like Luck of the Gambler are always on regardless of what power they're in.
IOs that proc, like Performance Shifter, have a % chance to go off whenever the power it's in is activated. If put in an auto power or toggle it will periodically proc as often as it's programmed to, as per the description, e.g. "roughly 1.5 times per minute".