Abstract: A vehicle antitheft system includes a MOSFET with associated power and logic circuitry embodied by a chip that can be housed within a starter solenoid housing for preventing control current from activating the solenoid unless an authorized enable signal is received. The enable signal can be transmitted by a hand-held rf transmitter. The chip can also undertake additional functions. In alternate embodiments, the MOSFET can be disposed in a housing separate from the solenoid and mounted near the solenoid, and the MOSFET can be controlled by an rf-generated enable signal or by an impulse-generated enable signal. In the latter case, the MOSFET is activated to close the solenoid control current circuit path only when a single impulse signal, e.g., from a door latch lock, is activated. If two impulse signals are received, one from, e.g., the door latch lock and another from, e.g.

Abstract: A vehicle antitheft system includes a housing that is supported by the vehicle's starting current power line between the vehicle's battery and the vehicle's starter motor. The starting current power line is cut, and one end of the line is advanced into an input channel that is established by an input bus bar in the housing. The other end of the line is advanced into an output channel that is established by an output bus bar in the housing. Plural MOSFETs are in electrical contact with the bus bars, and a control circuit controls the MOSFETs in response to a remotely generated rf enable signal. Consequently, the vehicle can be started by turning the ignition switch only after receipt of the enable signal. The starting current power line is held in the channels by set screws.

Abstract: A vehicle antitheft system includes a housing connectable to the casing of a starter motor and a silicon controlled rectifier (SCR) disposed in the housing. The system includes a battery connector which engages the starter motor power line from the battery, and a starter connector which engages the power terminal of the starter motor, with the SCR being in electrical series between the connectors. A control circuit is mounted in the housing, and the control circuit closes the power switch for a predetermined period upon receipt of an enable signal from a hand-held rf generator. Consequently, the vehicle can be started by turning the ignition switch only during the predetermined period.

Abstract: A vehicle antitheft system includes a housing connectable to the casing of a starter motor and a silicon controlled rectifier (SCR) disposed in the housing. The system includes a battery connector which engages the starter motor power line from the battery, and a starter connector which engages the power terminal of the starter motor, with the SCR being in electrical series between the connectors. A control circuit is mounted in the housing, and the control circuit closes the power switch for a predetermined period upon receipt of an enable signal from a hand-held rf generator. Consequently, the vehicle can be started by turning the ignition switch only during the predetermined period.