US3702469A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Alarm circuit for indicating failure in redundant power supplies
Assignee: GTE Automatic Electric Laboratories Inc
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Filing: 1971-09-03
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Granted: 1972-11-07
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Expires: 1991-09-03
Abstract
Abstract The output voltages of a pair of dual polarity power supplies are coupled together through associated solid state alarm-sense circuits to common utilization equipment. Each alarm-sense circuit comprises a pair of switching transistors connected to associated voltage dividers that are connected across the output lines of a power supply; a pair of transistors connected in parallel; and a lamp. The output lines supporting the same polarity voltages are connected together through steering diodes that prevent one supply loading the other. The switching transistors detect increases and decreases in supply voltages that are greater than prescribed amounts. In each alarm-sense circuit, the parallel connected transistors are responsive to the operation of the switching transistors to light the lamp to indicate failure of the associated power supply. Output signals of the alarm-sense circuits are connected to a bell for also producing an audio alarm when a power supply fails. A zener diode is connected to a voltage divider for causing a switching transistor to detect a supply failure when the absolute values of the opposite polarity supply voltages from an associated power supply increase at the same rate.
Inventors
- 👤 Joseph Golja
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 17:37
CPC Classifications
H; H02; H02H; H02H3/00; H02H3/24; H02H3/243; G; G01; G01D; G01D3/00; G01D3/08; H01; H01M; H01M10/00; H01M10/42; H01M10/48; H02H3/20; Y; Y02; Y02E; Y02E60/00; Y02E60/10
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
340 words
Apparatus for indicating failure of redundant power supplies that includes a pair of DC power supplies, each supply having a pair of output lines supplying output voltages of opposite polarity, comprising a pair of alarm circuits; means for connecting each alarm circuit across the output lines of a different associated power supply; and means for combining output signals from said alarm circuits for producing common output voltages of opposite polarity; each of said alarm circuits comprising a first transistor of one type having a collector electrode receiving the output voltages of one polarity frOm the power supplies, having an emitter electrode connected to a ground reference potential and having a base electrode; first bias means connected across the output lines of the associated power supply and to said first transistor base electrode for biasing said first transistor on during quiescent conditions when the power supplies operate satisfactorily; second bias means connected across the output lines of the associated power supply; a lamp; and second and third transistors of the one type having emitter electrodes connected to the ground reference potential; having base electrodes electrically connected to the first transistor collector electrode and to said second bias means, respectively, for biasing said second and third transistors off during quiescent conditions; and having collector electrodes connected in series through said lamp to receive the one polarity voltages from the power supplies; said first transistor being cut off and causing conduction of said second transistor and illumination of said lamp for indicating failure of the associated power supply when either the relative magnitude of the one polarity voltage, or the relative magnitude of the other polarity voltage, or both therefrom change in one direction an amount greater than a prescribed limit; said third transistor conducting and causing illumination of said lamp for indicating failure of the associated power supply when either the relative magnitude of the one polarity voltage, or the relative magnitude of the other polarity voltage, or both therefrom change in the other direction an amount greater than a prescribed limit.
Claim 2
Dependent Claim
340 words
Apparatus for indicating failure of redundant power supplies that includes a pair of DC power supplies, each supply having a pair of output lines supplying output voltages of opposite polarity, comprising a pair of alarm circuits; means for connecting each alarm circuit across the output lines of a different associated power supply; and means for combining output signals from said alarm circuits for producing common output voltages of opposite polarity; each of said alarm circuits comprising a first transistor of one type having a collector electrode receiving the output voltages of one polarity frOm the power supplies, having an emitter electrode connected to a ground reference potential and having a base electrode; first bias means connected across the output lines of the associated power supply and to said first transistor base electrode for biasing said first transistor on during quiescent conditions when the power supplies operate satisfactorily; second bias means connected across the output lines of the associated power supply; a lamp; and second and third transistors of the one type having emitter electrodes connected to the ground reference potential; having base electrodes electrically connected to the first transistor collector electrode and to said second bias means, respectively, for biasing said second and third transistors off during quiescent conditions; and having collector electrodes connected in series through said lamp to receive the one polarity voltages from the power supplies; said first transistor being cut off and causing conduction of said second transistor and illumination of said lamp for indicating failure of the associated power supply when either the relative magnitude of the one polarity voltage, or the relative magnitude of the other polarity voltage, or both therefrom change in one direction an amount greater than a prescribed limit; said third transistor conducting and causing illumination of said lamp for indicating failure of the associated power supply when either the relative magnitude of the one polarity voltage, or the relative magnitude of the other polarity voltage, or both therefrom change in the other direction an amount greater than a prescribed limit.
Claim 3
Dependent Claim
61 words
Apparatus according to claim 1 wherein each alarm circuit includes a pair of steering diodes, each diode being connected in series with a different output line of the associated power supply, said first, second and third transistor collector electrodes being connected to the one side of one diode that is spaced from the one output line supplying the one polarity voltage.
Claim 4
Dependent Claim
32 words
Apparatus according to claim 2 including means responsive to current in the common collector circuits of said second and third transistors for producing an audio indication of failure of a power supply.
Claim 5
Dependent Claim
132 words
Apparatus according to claim 3 wherein said second bias means comprises a resistive voltage divider connected across the supply output lines and a fourth transistor of the one type having a collector electrode electrically connected to the one side of the one diode, having a base electrode electrically connected to the voltage divider, and having an emitter electrode electrically connected to the base electrode of said third transistor, said fourth transistor being cut off during quiescent operation and conducting for causing said third transistor to conduct to illuminate said lamp to indicate failure of the associated power supply when either the relative magnitude of the one polarity voltage, or the relative magnitude of the other polarity voltage, or both therefrom change in the other direction an amount greater than a prescribed limit.
Claim 6
Dependent Claim
61 words
Apparatus according to claim 4 wherein said second bias means includes a zener diode electrically connected between said fourth transistor base electrode and the output line supporting the one polarity voltage from the associated supply for causing conduction of this transistor when the opposite polarity voltages therefrom each increase in absolute value more than a prescribed amount at the same rate.
Claim 7
Dependent Claim
56 words
Apparatus according to claim 5 wherein each alarm circuit comprises a relay including a coil connected in series with said second and third transistor collector electrodes and said lamp, and said audio indication producing means comprises an audio device responsive to operation of said relay for producing an audio indication of failure of a power supply.
Claim 8
Dependent Claim
115 words
Apparatus according to claim 5 wherein said audio indication producing means comprises an audio device and a relay electrically connected to the sides of said steering diOdes away from the supplies and to said audio device, said relay being normally energized to deactivate said audio device; and wherein said alarm circuits each comprise a fifth transistor of the opposite conduction type electrically connected across said relay and to said second and third transistor collector electrodes, said fifth transistor being responsive to conduction of either of said second and third transistors for conducting to short circuit and deenergize said relay to activate said audio device to produce an audio indication of failure of a power supply.
References Cited (Backward Citations)
US3431557A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-11-07 | 1976-05-08 | 1976-11-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-11-07 | 1980-05-08 | 1980-11-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-11-07 | 1984-05-08 | 1984-11-07 | $7700.00 | Window Closed / Lapsed |