초록 ▼

A vehicle anti-theft system that disables a vehicle engine upon detection of an unauthorized vehicle start-up, after the engine is running, by disconnecting the vehicle battery and draining the alternator voltage to ground through a resistor. A fob transmitter transmits a coded frequency signal that

A vehicle anti-theft system that disables a vehicle engine upon detection of an unauthorized vehicle start-up, after the engine is running, by disconnecting the vehicle battery and draining the alternator voltage to ground through a resistor. A fob transmitter transmits a coded frequency signal that is received by a receiver associated with the anti-theft system to arm the system. When the system is armed, it monitors whether the engine is running and has been recently started using a combination of vibration detection, voltage fluctuations in the battery voltage and the actual battery voltage. If the system determines that the engine is running and has been recently started, the system will issue a first command that opens a relay switch to disconnect the battery and a second command that closes a switch to connect the alternator to ground through the resistor. In order to prevent a vehicle from being jump started by using a second battery, the system includes a reset clock and associated delay that resets the decision to connect the alternator to ground at periodic intervals so as to repeatedly test for the presence of the second battery and cause the engine to stall after the second battery is disconnected. A driver entry detection portion of the system determines whether someone has entered the vehicle, and issues a chirp signal to notify the occupant that the system is armed. A state of charge algorithm is also provided to determine whether the battery voltage has reached a minimum state of charge for reliably starting the vehicle, and also disconnect the battery once the minimum level has been reached.

대표청구항 ▼

[ What is claimed is:] [1.] In a vehicle having an engine, a battery producing a battery voltage, and an electrical system with an alternator which produces an alternator voltage, an improvement characterized by an anti-theft system for disabling the engine for theft deterrent purposes, said anti-th

[ What is claimed is:] [1.] In a vehicle having an engine, a battery producing a battery voltage, and an electrical system with an alternator which produces an alternator voltage, an improvement characterized by an anti-theft system for disabling the engine for theft deterrent purposes, said anti-theft system comprising:a first circuit that can be closed to electrically connect the battery to the electrical system and opened to disconnect the battery from the electrical system;a second circuit including a resistive element, said second circuit being capable of being closed to connect the resistive element to alternator thereby pulling the alternator voltage to ground, and capable of being opened to disconnect the resistive element from the alternator; anda control system establishing an armed state and a disarmed state of the anti-theft system, said control system including a detection system that detects whether the engine is running and whether the engine has been recently started, said control system opening the first circuit and closing the second circuit, when the engine is started while the anti-theft system is armed.