Q:

Switch OFF-(ON)

Easy question here.
I'm designing a circuit which needs a switch for the main power supply. I would like a switch that keep the power OFF normally and the power ON while holding the push switch.
Is it what we called a SPST OFF-(ON) switch? How do we call the kind of switches that need to be hold?

A:

When purchasing switches, the state in parenthesis is momentary. Thus an "OFF-(ON)" switch will normally be open/off, and require you to operate it to close/on the circuit.
The term for any such switch with a momentary position is simply called a "momentary switch" or some variation depending on type (i.e. "momentary pushbutton", "momentary toggle", etc.)

