TATTLETALE® annunciators and Magnetic Switches are the nerve centres that translate Switchgauge contact operations into decisions and operate the alarm or shut down device. They are electrical load carrying devices for the alarm or shut down device. TATTLETALE® annunciators indicate which monitored function failed leading to the alarm or shutdown whereas magnetic switches do not. Magnetic switches operate basically as a latching relay. 117PH is use to shutdown 12V thru 32V distributor ignition or diesel engines. Breaks circuit when tripped. Opens distributor coil circuit or power circuit to diesel run device. Automatically disconnects from battery after trip.