US 5,473,200 A · Frequency modulation digital code anti-theft system

Abstract

A theft prevention device that includes a digital control unit and digital receiving units. These digital components form a control system along with existing peripheral components. The control system utilizes a signal network where signals are transmitted and received on the existing wiring or through the air between the digital components. The components of the anti-theft device operate in either an armed or disarmed state, and the system automatically arms whenever the ignition key is turned from on to off. If the system is in a vehicle and the vehicle is started without disarming the system first, each component becomes active after its programmed time delay has elapsed. A unique code, generated by the digital control unit, is passed through alarm system's signal network during the disarmed state such that the digital components in the theft prevention device becomes active and perform their respective functions even if the power supply is cut in the armed state.

Claims23

Dependent claims

A theft deterring device using existing peripheral components, comprising:

(a) a control system including a plurality of components, the plurality of components each having a memory, the control system entering an activated state when (i) the control system is in a second state of operation, (ii) a disruption occurs and (iii) a saved code saved in the memory of the plurality of components is not received by the plurality of components;
(b) a signal network coupling the plurality of components to each other;
and
(c) a code generator coupled to the control system, the code generator generating a generated code periodically when the second state of operation changes to a first state of operation, the generated code being passed among the plurality of components only during the first state of operation, the generated code being based on the saved code, and the saved code being periodically saved in the memories of the plurality of components.

1 more element

A theft deterring device for a motorized vehicle, incorporated into the vehicle's existing wiring and using the vehicle's peripheral components, comprising:

(a) a digital control system including a plurality of digital components, the plurality of digital components each having a memory, the digital control system entering an activated state when (i) the digital control system is in a second state of operation, (ii) a disruption occurs and (iii) a saved code saved in the memory of the plurality of digital components is not received by the plurality of digital components;
(b) a signal network connecting the plurality of digital components to each other, the signal network sending signals through the vehicle's existing wiring;
(c) a code generator coupled to the digital control system, the code generator generating a generated code periodically when a second state of operation changes to a first state of operation, the generated code being passed throughout the signal network only during the first state of operation, the generated code being based on the saved code, and the saved code being periodically saved in the memory of the plurality of digital components.

Dependencies are inferred from the claim text.

Frequency modulation digital code anti-theft system

Life of this patent

Frequency modulation digital code anti-theft system

Life of this patent

Abstract

Claims23