Key switch
Encyclopedia
Switch
In electronics, a switch is an electrical component that can break an electrical circuit, interrupting the current or diverting it from one conductor to another....
that can be activated only by a key
Key (lock)
A key is an instrument that is used to operate a lock. A typical key consists of two parts: the blade, which slides into the keyway of the lock and distinguishes between different keys, and the bow, which is left protruding so that torque can be applied by the user. The blade is usually intended to...
.
Key switches are usually used in situations where access needs to be restricted to the switch's functions.