Patent US3417235A successfully refreshed from Google Patents.
US3671934A
Expired / Lapsed
US
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Automobile theft alarm for detecting unauthorized energization of resistive load
Assignee: Harrison Systems Corp
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Filing: 1970-11-02
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Granted: 1972-06-20
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Expires: 1990-11-02
Abstract
Abstract This invention relates to a method and device for detecting and indicating the unauthorized entry into an automobile, the unauthorized use of an automobile, and/or the unauthorized removal of an accessory of an automobile. In this invention, a voltage sensing device designed to operate only when the rate-ofchange of a potential being sensed is greater than a predetermined value such as would occur when a resistive load is connected across the terminals of a battery. The rate-of-change voltage sensing device is coupled to monitor the voltage from the battery of a car. The rate-of-change voltage sensing device is not sensitive to and does not indicate the mere physical phenomena of a reduction in the battery terminal voltage. An inductive load such as motor or a coil, while it does result in a drop of battery terminal voltage, does not produce a pulse signal having a substantial rate-of-change and, therefore, will not initiate activation of the voltage sensing device. Thus, the voltage sensing device, when connected to a car battery, is selectively sensitive to the coupling of resistive loads to the battery, and insensitive to the operation of a normally operating accessory such as an electric clock.
Inventors
- 👤 Rudor M Teich
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 07:16
CPC Classifications
B; B60; B60R; B60R25/00; B60R25/10; B60R25/1003; B60R25/1004; B60R25/1001
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
153 words
An alarm device for indicating the unauthorized use of a vehicle of the type having a voltage source and one or more load devices adapted to be energized by said voltage source, comprising warning means adapted when activated to draw attention to said unauthorized use, first switch means opera-tively connected to said warning means and effective when actuated to activate said warning means, and second switch means operatively connected to said voltage source and to said first switch means, responsive to the rate of change of voltage across said voltage source, and effective to electrically connect said first switch means to said voltage source thereby to actuate said first switch means only when said rate of change of voltage exceeds a predetermined value corresponding generally to that resulting from the energization of a resistive load device, whereby said warning means is activated only in response to the energization of a resistive load device.
Claim 2
Dependent Claim
153 words
An alarm device for indicating the unauthorized use of a vehicle of the type having a voltage source and one or more load devices adapted to be energized by said voltage source, comprising warning means adapted when activated to draw attention to said unauthorized use, first switch means opera-tively connected to said warning means and effective when actuated to activate said warning means, and second switch means operatively connected to said voltage source and to said first switch means, responsive to the rate of change of voltage across said voltage source, and effective to electrically connect said first switch means to said voltage source thereby to actuate said first switch means only when said rate of change of voltage exceeds a predetermined value corresponding generally to that resulting from the energization of a resistive load device, whereby said warning means is activated only in response to the energization of a resistive load device.
Claim 3
Dependent Claim
14 words
The structure of claim 1, wherein said second switch means comprises a transistor network.
Claim 4
Dependent Claim
13 words
The structure of claim 1 wherein said switch means comprises a latching switch.
Claim 5
Dependent Claim
12 words
The structure of claim 1 wherein said switch means comprises an SCR.
Claim 6
Dependent Claim
13 words
The structure of claim 4 wherein said warming means comprises an audio device.
Claim 7
Dependent Claim
53 words
The structure of claim 1 including a pair of resistors connected in series with each other and in parallel with said second switch means, and means coupling the junction of said first and second resistors to a ground terminal through an accessory of the vehicle that is to be protected from unauthorized appropriation.
Claim 8
Dependent Claim
225 words
An alarm as defined in claim 1, wherein said voltage source has first and second terminals, said first switch means includes a control terminal, and wherein said second switch means comprises a switching device having a control terminal and first and second output terminals defining an output circuit, the output circuit of said switching device being operatively connected between said first terminal of said voltage source and said control terminal of said first switch means and effective when rendered conductive to operatively electrically connect said control terminal of said first switch means to said first terminal of said voltage source, thereby to actuate said first switch means, said switching device being rendered conductive upon the application of a potential difference of a given magnitude, between its control terminal and its first output terminal, and means operatively connecting said first output terminal and said control terminal of said switching device to said first terminal of said voltage source and effective to vary the rate of change of voltage of said first output terminal relative to that of said control terminal of said switching device as a function of the rate of change voltage at said first terminal of said voltage source, thereby to selectively render said switching device conductive in response to a rate of change of voltage at said voltage source exceeding said predetermined value.
Claim 9
Dependent Claim
41 words
An alarm as defined in claim 1, wherEin said voltage source has first and second terminals and wherein said second switch means comprises a switching device operatively connected between said first terminal of said voltage source and said first switch means.
Claim 10
Dependent Claim
42 words
An alarm as defined in claim 8, wherein said switching device comprises a semiconductor transistor having its emitter and base terminals operatively connected to said first terminal of said voltage source and its collector terminal operatively connected to said first switch means.
Claim 11
Dependent Claim
33 words
The alarm as defined in claim 7, wherein said rate-of-change of voltage varying means comprises an RC circuit operatively connected to said voltage source and to said control terminal of said switching device.
Claim 12
Dependent Claim
42 words
The alarm as defined in claim 10, wherein said RC circuit comprises a resistor and a capacitor connected in series across said voltage source, said control terminal of said switching device being connected to the junction between said resistor and said capacitor.
Claim 13
Dependent Claim
14 words
The structure of claim 7, wherein said first switch means comprises a latching switch.
Claim 14
Dependent Claim
33 words
The alarm as defined in claim 12, wherein said rate-of-change of voltage varying means comprises an RC circuit operatively connected to said voltage source and to said control terminal of said switching device.
Claim 15
Dependent Claim
42 words
The alarm as defined in claim 13, wherein said RC circuit comprises a resistor and a capacitor connected in series across said voltage source, said control terminal of said switching device being connected to the junction between said resistor and said capacitor.
Claim 16
Dependent Claim
13 words
The structure of claim 9, wherein said switch means comprises a latching switch.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-06-20 | 1975-12-20 | 1976-06-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-06-20 | 1979-12-20 | 1980-06-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-06-20 | 1983-12-20 | 1984-06-20 | $7700.00 | Window Closed / Lapsed |