US 6,982,631 B2
Automotive security system with self-biasing bypass immobilizer
Jonathan T. Kemper, San Diego, Calif. (US)
Assigned to Directed Electronics, Inc., Vista, Calif. (US)
Filed on Dec. 30, 2003, as Appl. No. 10/750,153.
Prior Publication US 2005/0146218 A1, Jul. 07, 2005
Int. Cl. B60R 25/04 (2006.01)
U.S. Cl. 340—426.11 59 Claims
OG exemplary drawing
 
1. A vehicle immobilizer device, comprising:
a switching element comprising first and second contacts electrically connected to a first system of a vehicle so that operation of the first system can be enabled when the first and second contacts are held together, and so that the first system is not operable when the first and second contacts are apart, the first contact being connected to a first source carrying a first voltage, the switching element further comprising a control input capable of receiving a control signal, the switching element causing the first and second contacts to be held together when the control signal is in a first control signal state and causing the first and second contacts to be brought apart when the control signal is not in the first control state;
a connection receiving an immobilizer signal from a security system, the immobilizer signal assuming a first immobilizer signal state when the security system determines to disable the vehicle, the immobilizer signal causing the control signal to assume the first control state when the immobilizer signal is not in the first immobilizer state; and
a biasing circuit receiving the first voltage through the first and second contacts and causing the control signal to assume the first control state when the second contact is connected to the first source through the first contact and the immobilizer signal is not in the first immobilizer state.