VEHICULAR ANTITHEFT DEVICE HAVING RELAY SWITCHES FOR INTERRUPTING INDUCTION COIL CIRCUIT AND FOR ACTIVATING AN ALARM

摘要

An antitheft device for automobiles and similar vehicles includes a pair of relay switches, one of which breaks the ignition circuit on both sides of the induction coil when the ignition switch is open. The other relay switch connects the battery with an alarm device whenever the circuit to the induction coil is disrupted either by severing the wires leading to the coil or by placing the coil at the same potential as the battery. The other relay switch also connects the alarm with an auxiliary battery whenever the automobile battery is disconnected from the ignition system. Thus, the antitheft device signals an alarm and renders the ignition system inoperative whenever a thief attempts to run a jumper wire from the battery to the induction coil. It also signals an alarm whenever the thief attempts to remove the battery.