US3775639A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Motor vehicle automatic headlamp switching system
Assignee: Motors Liquidation Co
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Filing: 1972-09-05
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Granted: 1973-11-27
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Expires: 1992-09-05
Abstract
Abstract A motor vehicle automatic headlamp switching system for automatically switching the headlamps between the high and low headlamp beams. Upon the illumination of a light sensitive element, associated control circuitry energizes the operating coil of an electrical relay which switches the headlamps from the high headlamp beams to the low headlamp beams. When the light sensitive element is no longer illuminated, the control circuit automatically deenergizes the operating coil of the electrical relay which switches the headlamps from the low headlamp beams to the high headlamp beams. Included in the control circuit is a delay circuit which prevents the control system from switching the headlamps from the high headlamp beams to the low headlamp beams upon the illumination of the light sensitive element by only short flashes of light.
Inventors
- 👤 M Woodward
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 22:13
CPC Classifications
B; B60; B60Q; B60Q1/00; B60Q1/02; B60Q1/04; B60Q1/14; B60Q1/1415; B60Q1/1423; B60Q2300/00; B60Q2300/05; B60Q2300/052; B60Q2300/40; B60Q2300/42
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
219 words
In an automotive vehicle exterior lighting system having headlamps of the dual filament type and an electrical relay for establishing, across a source of direct current potential, an energizing circuit for one filament of each headlamp while in one operating condition and an energizing circuit for the other one filament of each headlamp when operated to the alternate condition of operation upon the energization of an associated operating coil, a control circuit for said relay comprising, circuitry including a light sensitive element positioned to be illuminated by light projected upon the front of said vehicle for producing a control signal each time said light sensitive element is illuminated, a transistor having a control electrode and two current carrying electrodes connected across the positive and negative polarity terminals of said source of direct current potential responsive to said control signal for producing a switching signal, circuit means responsive to said switching signal for establishing an energizing circuit for said operating coil of said electrical relay across said source of direct current potential, a capacitor, a resistor, a diode, means for connecting the series combination of said capacitor and said resistor across said current carrying electrodes of said transistor, and means for connecting said diode between said control electrode of said transistor and the junction between said capacitor and said resistor.
Claim 2
Dependent Claim
219 words
In an automotive vehicle exterior lighting system having headlamps of the dual filament type and an electrical relay for establishing, across a source of direct current potential, an energizing circuit for one filament of each headlamp while in one operating condition and an energizing circuit for the other one filament of each headlamp when operated to the alternate condition of operation upon the energization of an associated operating coil, a control circuit for said relay comprising, circuitry including a light sensitive element positioned to be illuminated by light projected upon the front of said vehicle for producing a control signal each time said light sensitive element is illuminated, a transistor having a control electrode and two current carrying electrodes connected across the positive and negative polarity terminals of said source of direct current potential responsive to said control signal for producing a switching signal, circuit means responsive to said switching signal for establishing an energizing circuit for said operating coil of said electrical relay across said source of direct current potential, a capacitor, a resistor, a diode, means for connecting the series combination of said capacitor and said resistor across said current carrying electrodes of said transistor, and means for connecting said diode between said control electrode of said transistor and the junction between said capacitor and said resistor.
Claim 3
Dependent Claim
223 words
In an automotive vehicle exterior lighting system having headlamps of the dual filament type and an electrical relay for establishing, across a source of direct current potential, an energizing circuit for one filament of each headlamp while in one operating condition and an energizing circuit for the other one filament of each headlamp when operated to the alternate condition of operation upon the energization of an associated operating coil, a control circuit for said relay comprising, circuitry including a light sensitive element positioned to be illuminated by light projected upon the front of said vehicle for producing a control signal each time said light sensitive element is illuminated, a transistor having a base electrode and a collector electrode and an emitter electrode connected across the positive and negative polaritY terminals of said source of direct current potential responsive to said control signal for producing a switching signal, circuit means responsive to said switching signal for establishing an energizing circuit for said operating coil of said electrical relay across said source of direct current potential, a capacitor, a resistor, a diode, means for connecting the series combination of said capacitor and said resistor across said collector and emitter electrodes of said transistor, and means for connecting said diode between said base electrode of said transistor and the junction between said capacitor and said resistor.
Claim 4
Dependent Claim
223 words
In an automotive vehicle exterior lighting system having headlamps of the dual filament type and an electrical relay for establishing, across a source of direct current potential, an energizing circuit for one filament of each headlamp while in one operating condition and an energizing circuit for the other one filament of each headlamp when operated to the alternate condition of operation upon the energization of an associated operating coil, a control circuit for said relay comprising, circuitry including a light sensitive element positioned to be illuminated by light projected upon the front of said vehicle for producing a control signal each time said light sensitive element is illuminated, a transistor having a base electrode and a collector electrode and an emitter electrode connected across the positive and negative polaritY terminals of said source of direct current potential responsive to said control signal for producing a switching signal, circuit means responsive to said switching signal for establishing an energizing circuit for said operating coil of said electrical relay across said source of direct current potential, a capacitor, a resistor, a diode, means for connecting the series combination of said capacitor and said resistor across said collector and emitter electrodes of said transistor, and means for connecting said diode between said base electrode of said transistor and the junction between said capacitor and said resistor.
Claim 5
Dependent Claim
257 words
In an automotive vehicle exterior lighting system having headlamps of the dual filament type and an electrical relay for establishing, across a source of direct current potential, an energizing circuit for one filament of each headlamp while in one operating condition and an energizing circuit for the other one filament of each headlamp when operated to the alternate condition of operation upon the energization of an associated operating coil, a control circuit for said relay comprising, circuitry including a light sensitive element positioned to be illuminated by light projected upon the front of said vehicle for producing a control signal each time said light sensitive element is illuminated, a transistor having a base electrode and a collector electrode and an emitter electrode connected across the positive and negative polarity terminals, respectively, of said source of direct current potential responsive to said control signal applied across said base-emitter electrodes for producing a switching signal, circuit means responsive to said switching signal for establishing an energizing circuit for said operating coil of said electrical relay across said source of direct current potential, a capacitor, a resistor, a diode having anode and cathode electrodes, means for connecting the series combination of said capacitor and said resistor across said collector electrode of said transistor and the negative polarity terminal of said source of direct current potential, means for connecting said anode electrode of said diode to said base electrode of said transistor, and means for connecting said cathode electrode of said diode to the junction between said capacitor and said resistor.
Claim 6
Dependent Claim
257 words
In an automotive vehicle exterior lighting system having headlamps of the dual filament type and an electrical relay for establishing, across a source of direct current potential, an energizing circuit for one filament of each headlamp while in one operating condition and an energizing circuit for the other one filament of each headlamp when operated to the alternate condition of operation upon the energization of an associated operating coil, a control circuit for said relay comprising, circuitry including a light sensitive element positioned to be illuminated by light projected upon the front of said vehicle for producing a control signal each time said light sensitive element is illuminated, a transistor having a base electrode and a collector electrode and an emitter electrode connected across the positive and negative polarity terminals, respectively, of said source of direct current potential responsive to said control signal applied across said base-emitter electrodes for producing a switching signal, circuit means responsive to said switching signal for establishing an energizing circuit for said operating coil of said electrical relay across said source of direct current potential, a capacitor, a resistor, a diode having anode and cathode electrodes, means for connecting the series combination of said capacitor and said resistor across said collector electrode of said transistor and the negative polarity terminal of said source of direct current potential, means for connecting said anode electrode of said diode to said base electrode of said transistor, and means for connecting said cathode electrode of said diode to the junction between said capacitor and said resistor.
References Cited (Backward Citations)
US2850674A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-11-26 | 1977-05-28 | 1977-11-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-11-26 | 1981-05-28 | 1981-11-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-11-26 | 1985-05-28 | 1985-11-27 | $7700.00 | Window Closed / Lapsed |