US3593264A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Vehicle warning circuit
Assignee: Cooper Industries LLC
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Filing: 1968-07-05
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Granted: 1971-07-13
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Expires: 1988-07-05
Abstract
Abstract A warning circuit is provided for informing the operator of a vehicle when a remotely positioned vehicle lamp fails to light. The circuit includes a sensing circuit having a plurality of resistors connected in series with the lamps. A semiconductor circuit is coupled to the resistors and transmits an electrical signal to a warning means which may include a lamp or a buzzer. The circuit can be made to operate at any time the lamp switch is turned on. Operation of the circuit may be also limited to the condition when the ignition switch is turned on.
Inventors
- 👤 Carl E Atkins
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 20:02
CPC Classifications
B; B60; B60Q; B60Q11/00; B60Q11/005
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
178 words
A vehicle warning circuit for producing a warning whenever a lamp is not passing current comprising; a source of direct current power; an ignition switch for supplying current from the power source to an ignition circuit to operate the vehicle engine; a plurality of lamps connected in parallel on the vehicle which are lighted for signalling purposes; a lamp switch connected between the power source and the lamps for lighting them; a plurality of resistors connected in series with the lamps for supplying a potential drop which is responsive to the current through the lamps; a sensing circuit that includes a sensing transistor having its collector electrode and its base electrode connected across the resistors, said transistor being arranged to generate an output signal only when the voltage drop across said resistors is less than a predetermined voltage, said lowered voltage indicating that at least one lamp is not passing current; and a semiconductor switch having its input terminals coupled to the sensing circuit and its output connected in series between a warning device and the power source.
Claim 2
Dependent Claim
178 words
A vehicle warning circuit for producing a warning whenever a lamp is not passing current comprising; a source of direct current power; an ignition switch for supplying current from the power source to an ignition circuit to operate the vehicle engine; a plurality of lamps connected in parallel on the vehicle which are lighted for signalling purposes; a lamp switch connected between the power source and the lamps for lighting them; a plurality of resistors connected in series with the lamps for supplying a potential drop which is responsive to the current through the lamps; a sensing circuit that includes a sensing transistor having its collector electrode and its base electrode connected across the resistors, said transistor being arranged to generate an output signal only when the voltage drop across said resistors is less than a predetermined voltage, said lowered voltage indicating that at least one lamp is not passing current; and a semiconductor switch having its input terminals coupled to the sensing circuit and its output connected in series between a warning device and the power source.
Claim 3
Dependent Claim
48 words
A warning circuit as claimed in claim 1 wherein a portion of the sensing circuit is connected to the junction of the ignition switch and the ignition circuit, said connection applying a positive voltage to the sensing circuit for operating it only when the ignition switch is closed.
Claim 4
Dependent Claim
25 words
A warning circuit as claimed in claim 1 wherein the warning device is a lamp mounted to be viewed by an operator of the vehicle.
Claim 5
Dependent Claim
52 words
A warning circuit as claimed in claim 4 wherein a plurality of sockets are provided at the junction point of said resistors for connection to the signal lamp circuit, said sockets providing an adjusting means for matching the potential drop through the resistors to the number of signal lamps in the circuit.
Claim 6
Dependent Claim
71 words
A warning circuit as claimed in claim 1 wherein the base electrode of said sensing transistor is coupled to the collector of a compensating transistor stage, said compensating transistor mounted in close proximity to the sensing transistor for attaining the same temperature as the sensing transistor, said connection between the compensating and sensing transistors for adjusting the voltage bias on the sensing transistor to maintain its sensitivity at all operating temperatures.
Claim 7
Dependent Claim
36 words
A warning circuit as claimed in claim 1 wherein said semiconductor switch includes a PNP transistor and an NPN transistor with the collector electrode of each transistor connected to the base electrode of the other transistor.
Claim 8
Dependent Claim
39 words
A warning circuit as claimed in claim 6 wherein a capacitor is connected across the base and emitter electrodes of each transistor in the semiconductor switch for passing high frequency impulses and for delaying the actuation of the switch.
References Cited (Backward Citations)
US3271736A
Cited
US3408625A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-07-12 | 1975-01-11 | 1975-07-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-07-12 | 1979-01-11 | 1979-07-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-07-12 | 1983-01-11 | 1983-07-13 | $7700.00 | Window Closed / Lapsed |