Vehicle security system
First Claim
1. A vehicle security system for a vehicle having an ignition circuit which may selectively be on or off, said vehicle security system comprising:
- at least one sensor, said sensor having a rest state and tripped state;
a controller having an armed state and a disarmed state; and
an output device driver having a quiescent state and an alarm state;
said output device driver transitioning from said quiescent state to said alarm state in response to said sensor transitioning from said rest state to said tripped state when said controller is in said armed state and said ignition circuit is off, said output device driver remaining in said quiescent state when said controller is in said armed state and said ignition circuit is on independently of the present state of said sensor;
said sensor including a capacitor having a first plate and a second plate, said first plate being coupled to said controller, each of said first plate and said second plate having a first bias potential applied thereto so that said capacitor is discharged;
said second plate of said capacitor being adapted to be coupled electrically to a normally open circuit of said vehicle, said open circuit applying a second potential different from said bias potential to said second plate when said open circuit becomes closed, said first plate momentarily transitioning to said second potential to signal said controller that said sensor is tripped.
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0 Petitions
Accused Products
Abstract
A vehicle security system includes at least one sensor, a controller and at least one output device driver. The sensor has a rest state and a tripped state. The controller has an armed state and a disarmed state. The first output device driver transitions from its quiescent to its alarm state in response to the first sensor transitioning from its rest state to its trip state and the controller is in its armed state and furthermore when the ignition circuit is off. The first output device driver will remain in the quiescent state independently of the present state of the sensor if the ignition circuit is on and the controller is in its armed state. If the controller is in the disarm state, any activity by the sensor will not have any effect on the system.
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Citations
35 Claims
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1. A vehicle security system for a vehicle having an ignition circuit which may selectively be on or off, said vehicle security system comprising:
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at least one sensor, said sensor having a rest state and tripped state; a controller having an armed state and a disarmed state; and an output device driver having a quiescent state and an alarm state; said output device driver transitioning from said quiescent state to said alarm state in response to said sensor transitioning from said rest state to said tripped state when said controller is in said armed state and said ignition circuit is off, said output device driver remaining in said quiescent state when said controller is in said armed state and said ignition circuit is on independently of the present state of said sensor; said sensor including a capacitor having a first plate and a second plate, said first plate being coupled to said controller, each of said first plate and said second plate having a first bias potential applied thereto so that said capacitor is discharged; said second plate of said capacitor being adapted to be coupled electrically to a normally open circuit of said vehicle, said open circuit applying a second potential different from said bias potential to said second plate when said open circuit becomes closed, said first plate momentarily transitioning to said second potential to signal said controller that said sensor is tripped. - View Dependent Claims (2, 3, 4, 5)
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6. A vehicle security system for a vehicle having an ignition circuit which may selectively be on or off, said vehicle security system comprising:
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at least one sensor, said sensor having a rest state and tripped state; a controller having an armed state and a disarmed state; and an output device driver having a quiescent state and an alarm state; said output device driver transitioning from said quiescent state to said alarm state in response to said sensor transitioning from said rest state to said tripped state when said controller is in said armed state and said ignition circuit is off, said output device driver remaining in said quiescent state when said controller is in said armed state and said ignition circuit is on independently of the present state of said sensor; said sensor including a capacitor having a first plate and a second plate, said first plate being coupled to said controller, said first plate and said second plate each being at a first bias potential, and a diode being electrically coupled between said second plate and a further circuit of said vehicle which is normally at a second potential, said diode becoming forward biased when said further circuit is at a third potential which couples said second plate to said third potential, said first plate momentarily transitioning to said third potential in response thereto to signal said controller that said sensor is tripped. - View Dependent Claims (7, 8, 9, 10, 11)
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12. A vehicle security system for a vehicle having an ignition circuit which may selectively be on or off, said vehicle security system comprising:
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at least one sensor, said sensor having a rest state and tripped state; a controller having an armed state and a disarmed state; and an output device driver having a quiescent state and an alarm state; said output device driver transitioning from said quiescent state to said alarm state in response to said sensor transitioning from said rest state to said tripped state when said controller is in said armed state and said ignition circuit is off, said output device driver remaining in said quiescent state when said controller is in said armed state and said ignition circuit is on independently of the present state of said sensor; said sensor including a capacitor having a first plate and a second plate, said first plate being coupled to said controller, each of said first plate and said second plate being biased at a first bias potential, and a transistor circuit coupled between said second plate and a further circuit of said vehicle which is normally at a second potential, said transistor circuit changing state when said further circuit is at a third potential at which said transistor circuit couples said third potential to said second plate, said first plate momentarily transitioning to said third potential in response thereto to signal said controller that said sensor is tripped. - View Dependent Claims (13, 14, 15, 16, 17)
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18. A vehicle security system for a vehicle having an ignition circuit which may selectively be on or off, said vehicle security system comprising:
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at least one sensor, said sensor having a rest state and tripped state; a controller having an armed state and a disarmed state; and an output device driver having a quiescent state and an alarm state; said output device driver transitioning from said quiescent state to said alarm state in response to said sensor transitioning from said rest state to said tripped state when said controller is in said armed state and said ignition circuit is off, said output device driver remaining in said quiescent state when said controller is in said armed state and said ignition circuit is on independently of the present state of said sensor; said sensor including a current sensing circuit responsive to a battery potential and an alternator potential of said vehicle such that said circuit develops a pulse in response to a current developed in said alternator circuit dropping said alternator potential less than said battery potential, said pulse indicating said sensor being in said tripped state, and a first capacitor having a first plate and a second plate, said first plate being coupled to said controller, said capacitor being normally biased to be discharged, said pulse being applied to said second plate to signal said controller that said sensor is tripped. - View Dependent Claims (19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30)
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31. A vehicle security system for a vehicle having an ignition circuit which may selectively be on or off, said vehicle security system comprising:
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means responsive to an unauthorized tampering of said vehicle for developing a sensor tripped signal; a controller including means responsive to an externally developed arm/disarm signal for transitioning said controller between each of an armed state and a disarmed state upon each occurrence of said arm/disarm signal, means responsive to said sensor tripped signal for developing an output triggered signal when said controller is in said armed state and means responsive to said ignition circuit being on for disabling said output triggered signal developing means even if said controller received said tripped signal when in said arm state; and means responsive to said triggered signal for developing either one of an audible alarm and visible alarm. - View Dependent Claims (32, 33, 34, 35)
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Specification