Mercury switches can handle high currents even some DC motors directly. Do switching in hazardous locations, work from temperatures as mechanical bi-metal thermostats, serve as pressure switch tilt alarms, warn your robot the hill is too steep (do no use if robot is in rough ground) or mounted and tilted to be triggered by acceleration.
In this circuit, mercury switch is connected as regular switch at lower NO Push Button connection. Above push button is RESET after mercury switch trips.
