Passive security device
First Claim
1. A passive security device, for use with vehicles having an electrical system including a starter, and an ignition switch having "on" and "accessory" contacts, said device comprising:
- first means for connecting said device to the electrical system;
detection and alarm means including trigger means for detecting voltage variations and producing an electrical signal in response thereto, said trigger means being connected to said first means, generating means for converting said electrical signal into a square wave signal, said generating means being connected to said trigger means, siren means for sounding an alarm, and activating means connecting said generating means and said siren means and being responsive to said square wave signal to activate said siren means;
first passive means for arming said detection and alarm means;
second passive means for arming an ignition cut-out circuit; and
disarming means connected between said first means and said first and second passive means.
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Accused Products
Abstract
An antitheft device for a motor vehicle has a pushbutton disarming circuit coupled to a passive ignition cut-out circuit and to a passive arming circuit. The ignition cut-out circuit is interposed in the automobile ignition circuit and includes an SCR switchable from "on" to "off" by the disarming circuit to permit ignition. The passive arming circuit includes a Darlington amplifier configuration, is interposed in the automobile ignition circuit, and is coupled through an exit delay circuit to the remaining circuit portions of the device: interval timing and activating circuit, square-wave generator, trigger, entrace delay and siren circuits. The amplifier configuration supplies power to operate the circuits until switched by proper actuation of the disarming circuit and automobile ignition.
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Citations
11 Claims
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1. A passive security device, for use with vehicles having an electrical system including a starter, and an ignition switch having "on" and "accessory" contacts, said device comprising:
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first means for connecting said device to the electrical system; detection and alarm means including trigger means for detecting voltage variations and producing an electrical signal in response thereto, said trigger means being connected to said first means, generating means for converting said electrical signal into a square wave signal, said generating means being connected to said trigger means, siren means for sounding an alarm, and activating means connecting said generating means and said siren means and being responsive to said square wave signal to activate said siren means; first passive means for arming said detection and alarm means; second passive means for arming an ignition cut-out circuit; and disarming means connected between said first means and said first and second passive means. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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Specification