Patent US3748494A successfully refreshed from Google Patents.
US3748494A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Vehicle alarm system
Assignee: Curtis Dyna Products Corp
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Filing: 1971-04-14
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Granted: 1973-07-24
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Expires: 1991-04-14
Abstract
Abstract A sensitive current detector includes the vehicle ammeter and is responsive to current therein to activate a first pulser which sets a monostable multivibrator which activates another pulser having an output to the vehicle horn relay to sound the horn at a 2 cycle per second (Hz) frequency. The monostable multivibrator resets after 1 minute of sounding of the horn to deactivate the horn unless the current detector continues to sense current. A delay timer responds to a key operated switch or a remote disable switch to inhibit, for 15 seconds, activation of the second pulser by the monostable. The monostable multivibrator can also be set by mechanically operable switches.
Inventors
- 👤 P Nine
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 10:56
CPC Classifications
B; B60; B60R; B60R25/00; B60R25/10; B60R25/1004; G; G08; G08B; G08B13/00; G08B13/02; G08B13/08; H; H03; H03K; H03K17/00; H03K17/28; H03K3/00; H03K3/02; H03K3/26; H03K3/28; H03K3/281; H03K3/284; B60R2025/1013; B60R25/1003
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
126 words
A sensing method for an alarm system and comprising the steps of: applying a potential to a diode-connected transistor to provide a first current therein establishing a desired base-emitter voltage therein, applying the base-emitter voltage of saiD diode-connected transistor across a series combination of the base-emitter junction of a second transistor, an impedance, and a portion of a vehicle electrical system, thereby normally maintaining a forward bias on said second transistor to keep it normally conducting, and applying a potential across the combination of said series combination in series with a second impedance, and thereby establishing at said second impedance a voltage dependent on the current in said series combination as influenced and varied by change of resistance of said portion of said vehicle electrical system.
Claim 2
Dependent Claim
126 words
A sensing method for an alarm system and comprising the steps of: applying a potential to a diode-connected transistor to provide a first current therein establishing a desired base-emitter voltage therein, applying the base-emitter voltage of saiD diode-connected transistor across a series combination of the base-emitter junction of a second transistor, an impedance, and a portion of a vehicle electrical system, thereby normally maintaining a forward bias on said second transistor to keep it normally conducting, and applying a potential across the combination of said series combination in series with a second impedance, and thereby establishing at said second impedance a voltage dependent on the current in said series combination as influenced and varied by change of resistance of said portion of said vehicle electrical system.
Claim 3
Dependent Claim
114 words
In an alarm system for a vehicle electrical system, a sensor comprising: a constant current source having a normally conducting diode-connected biasing transistor with the emitter-collector path thereof in series with a first impedance means across an energy supply, and a normally conducting current source transistor having its base coupled to the collector of said biasing transistor and normally forward biased by the emitter-base voltage of said biasing transistor, and having its emitter-collector path coupled in series with a second impedance means and a portion of said vehicle electrical system in a circuit with said energy supply, the said current source transistor having an output conductor coupled thereto to produce an output signal thereon.
Claim 4
Dependent Claim
114 words
In an alarm system for a vehicle electrical system, a sensor comprising: a constant current source having a normally conducting diode-connected biasing transistor with the emitter-collector path thereof in series with a first impedance means across an energy supply, and a normally conducting current source transistor having its base coupled to the collector of said biasing transistor and normally forward biased by the emitter-base voltage of said biasing transistor, and having its emitter-collector path coupled in series with a second impedance means and a portion of said vehicle electrical system in a circuit with said energy supply, the said current source transistor having an output conductor coupled thereto to produce an output signal thereon.
Claim 5
Dependent Claim
29 words
The alarm system of claim 2 wherein: said vehicle electrical system portion is one in common circuit relationship with a plurality of electrical devices of the vehicle electrical system.
Claim 6
Dependent Claim
58 words
The alarm system of claim 3 wherein: said sensor includes in the series coupling of the emitter-collector path of said current source transistor and said second impedance means and said electrical system portion in said circuit, third impedance means to establish the level of said sensor signal output in response to current flowing in said electrical system portion.
Claim 7
Dependent Claim
70 words
The alarm system of claim 4 wherein: said electrical system portion is resistance of an ammeter in series with said energy supply and the load of at least one of said electrical devices, said resistance rising upon flow of current from said energy supply through said load to reduce current in the emitter collector path of said current source transistor to thereupon change the level of said sensor signal output.
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) | 1976-07-23 | 1977-01-22 | 1977-07-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-07-23 | 1981-01-22 | 1981-07-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-07-23 | 1985-01-22 | 1985-07-24 | $7700.00 | Window Closed / Lapsed |