US3771012A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Battery protective circuit for emergency lighting systems
Assignee: General Electric Co
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Filing: 1972-05-24
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Granted: 1973-11-06
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Expires: 1992-05-24
Abstract
Abstract This invention provides improved circuitry for holding an inverter of an emergency lighting system in an off condition until a normal power source falls below a predetermined voltage level and circuitry to protect a battery from deep discharges when it is called upon to deliver auxiliary power to a lighting system via said inverter. The protective circuitry includes the short circuiting of one of a plurality of windings of a transformer of the inverter upon the battery voltage falling below a predetermined level. The shorting of one winding causes the inverter, which includes other windings of the transformer, to cease oscillation, and therefore substantially cease to draw power from the battery. The battery can thereby recover in substantially unloaded condition, prolonging its useful life. Means are provided for allowing the battery to repower the inverter when the battery has recovered sufficiently. This results in a cyclical operation of the emergency lighting system causing the lights to flash as the battery recovers and discharges. This recovery and discharge cycle prolongs the operating time of the lighting system when under emergency power and prolongs the life of the battery.
Inventors
- 👤 W Niederjohn
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 07:52
CPC Classifications
H; H02; H02M; H02M7/00; H02M7/42; H02M7/44; H02M7/48; H02M7/53; H02M7/537; H02M7/5383; H02M7/53846; H02M7/53862; H02J; H02J7/00; H02J7/60; H02J7/663; H02J9/00; H02J9/04; H02J9/06; H02J9/062; H02J9/065; H05; H05B; H05B41/00; H05B41/14; H05B41/26; H05B41/28; H05B41/282; H05B41/285; H05B41/2851; H05B41/2853; H05B41/2856; Y; Y02; Y02B; Y02B70/00; Y02B70/30; Y04; Y04S; Y04S20/00; Y04S20/20
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
95 words
A lighting system including means for developing emergency power for said lighting system from a battery upon failure of a normal power source for powering said lighting system, said means for developing emergency power for said lighting system from said battery comprising an oscillator circuit including a plurality of transformer windings, and means for controlling said oscillator circuit, said means for controlling said oscillator circuit comprising means for shortcircuiting one of said plurality of transformer windings to inhibit oscillation of said oscillating circuit when the voltage of said battery drops to a predetermined voltage level.
Claim 2
Dependent Claim
95 words
A lighting system including means for developing emergency power for said lighting system from a battery upon failure of a normal power source for powering said lighting system, said means for developing emergency power for said lighting system from said battery comprising an oscillator circuit including a plurality of transformer windings, and means for controlling said oscillator circuit, said means for controlling said oscillator circuit comprising means for shortcircuiting one of said plurality of transformer windings to inhibit oscillation of said oscillating circuit when the voltage of said battery drops to a predetermined voltage level.
Claim 3
Dependent Claim
79 words
A lighting system as set forth in claim 1 wherein said means for short-circuiting one of said plurality of transformer windings comprises: a switching device effectively connected across said one of said plurality of transformer windings and having a conductive and a non-conductive state, said switching device being in said non-conductive state when the battery is above a predetermined level, and said switching device being in said conductive state when said battery is at or below said predetermined level.
Claim 4
Dependent Claim
24 words
A lighting system as set forth in claim 1 including means for inhibiting said oscillator circuit prior to failure of said normal power source.
Claim 5
Dependent Claim
81 words
A lighting system including means for developing emergency power for said lighting system from a battery upon failure of a normal power source for powering said lighting system, said means for developing emergency power for said lighting system from said battery comprising an oscillator circuit, means including a tuning winding for controlling said oscillator circuit, and means for short-circuiting said tuning winding to inhibit oscillation of said oscillator circuit when the voltage of said battery drops to a predetermined voltage level.
Claim 6
Dependent Claim
81 words
A lighting system including means for developing emergency power for said lighting system from a battery upon failure of a normal power source for powering said lighting system, said means for developing emergency power for said lighting system from said battery comprising an oscillator circuit, means including a tuning winding for controlling said oscillator circuit, and means for short-circuiting said tuning winding to inhibit oscillation of said oscillator circuit when the voltage of said battery drops to a predetermined voltage level.
Claim 7
Dependent Claim
115 words
A lighting system as set forth in claim 4 wherein said means for short-circuiting said tuning winding comprises: a first switching device, said first switching device being conductive when said battery has a voltage level above said predetermined level and being non-conductive when the voltage of said battery drops to said predetermined level, and a second switching device connected across said tuning winding and coupled to said first switching device, said second switching device being non-conductive when said first switching device is conductive, and being conductive when said first switching device is non-conductive, said tuning winding being short-circuited upon said second switching device being rendered conductive whereby the oscillation of said oscillator circuit is inhibited.
Claim 8
Dependent Claim
25 words
A lighting system according to claim 5 wherein said first switching device is a transistor and said second switching device is a silicon controlled rectifier.
Claim 9
Dependent Claim
39 words
A lighting system according to claim 5 including means for reinitiating oscillation of said oscillator circuit when said battery has recovered to an extent that its voltage has reached a second voltage level higher than said predetermined voltage level.
Claim 10
Dependent Claim
18 words
A lighting system according to claim 7 wherein said Means for reinitiating oscillation is a voltage breakover device.
Claim 11
Dependent Claim
17 words
A lighting system according to claim 8 and wherein said voltage breakover device is a Zener diode.
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) | 1976-11-05 | 1977-05-07 | 1977-11-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-11-05 | 1981-05-07 | 1981-11-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-11-05 | 1985-05-07 | 1985-11-06 | $7700.00 | Window Closed / Lapsed |