US3805142A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Current limit circuit with superseding characteristic to activate overcurrent protection circuit
Assignee: AT&T Inc
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Filing: 1973-01-10
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Granted: 1974-04-16
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Expires: 1993-01-10
Abstract
Abstract A current and voltage regulated DC to DC converter is designed with protection features to permit its operation in parallel with like DC to DC converters. The features are designed to assure shutdown protection against overcurrent and overvoltage conditions and to assure that each converter will contribute a current to the common load. The protection features include a selective high voltage shutdown to shut down only the converter causing an overvoltage and an overcurrent protection circuit to supersede the normal current regulation in response to a fault condition. A reverse current shutdown circuit protects the common load from faults and short circuits internal to the converter circuit. These protection features permit the converters to operate in parallel without shutting down the entire system should an individual converter malfunction.
Inventors
- 👤 R Rando
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 02:33
CPC Classifications
H; H02; H02M; H02M3/00; H02M3/22; H02M3/24; H02M3/28; H02M3/305; H02M3/315; H02M3/3155
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
109 words
In a converter circuit, control circuit means to control the output of said converter comprising, means to regulate the current output of said converter, means to monitor the voltage output of said converter, a reference voltage source, means to compare the voltage monitored by said means to monitor with the reference voltage of said source, means responsive to said means to compare to disable said means to regulate the current when said voltage monitored decreases below the reference voltage of said source, means to establish a current threshold larger than the regulated current value, and means to shut down the converter when its current output exceeds said current threshold.
Claim 2
Dependent Claim
109 words
In a converter circuit, control circuit means to control the output of said converter comprising, means to regulate the current output of said converter, means to monitor the voltage output of said converter, a reference voltage source, means to compare the voltage monitored by said means to monitor with the reference voltage of said source, means responsive to said means to compare to disable said means to regulate the current when said voltage monitored decreases below the reference voltage of said source, means to establish a current threshold larger than the regulated current value, and means to shut down the converter when its current output exceeds said current threshold.
Claim 3
Dependent Claim
68 words
In a converter circuit as described in claim 1 wherein said converter includes output means to connect to a load, said means to control the output includes means to monitor the direction of current flow in the output means of said converter, and means to actuate said means to shut down and means to disconnect said output means from a load if a particular current direction is detected.
Claim 4
Dependent Claim
108 words
A power supply comprising switching means, output means, means to monitor the current of said output means, a current reference signal, means to compare the current sensed by said means to monitor with said current reference signal, current regulation means responsive to said means to compare to control the switching of said switching means, wherein the improvement comprises, means to monitor the output voltage of said output means, means to disable said current regulation means responsive to said means to monitor the output voltage when the output voltage is below a predetermined threshold, and overcurrent shutdown means to shut down the power supply in response to an overcurrent.
Claim 5
Dependent Claim
108 words
A power supply comprising switching means, output means, means to monitor the current of said output means, a current reference signal, means to compare the current sensed by said means to monitor with said current reference signal, current regulation means responsive to said means to compare to control the switching of said switching means, wherein the improvement comprises, means to monitor the output voltage of said output means, means to disable said current regulation means responsive to said means to monitor the output voltage when the output voltage is below a predetermined threshold, and overcurrent shutdown means to shut down the power supply in response to an overcurrent.
Claim 6
Dependent Claim
52 words
A power supply as defined in claim 3 wherein the improvement further includes, means to monitor the direction of current flow in said output means, level detector means responsive to said means to monitor the direction of current, and means responsive to said level detector means to actuate said overcurrent shutdown means.
Claim 7
Dependent Claim
186 words
A DC to DC converter connected to an output comprising means to regulate the current ouput of said converter including means to sense the current output, a current reference signal source, means to compare the current output sensed by said means to sense the current output with the signal of said current reference signal source, and means responsive to said means to compare to control the current output of said converter wherein the improvement comprises means to monitor the voltage output of said converter, a voltage reference signal source, means to disable said means to compare when the voltage detected by said means to monitor the voltage output decreases below the signal of said voltage reference signal source, a first operational amplifier connected as an amplifier to detect the current in said means to sense the current output, an overcurrent reference signal source, a second operational amplifier responsive to said first operational amplifier and said overcurrent reference signal source, said second operational amplifier generating a signal in response to an overcurrent, and means responsive to said second operational amplifier to disconnect said converter from said output.
Claim 8
Dependent Claim
186 words
A DC to DC converter connected to an output comprising means to regulate the current ouput of said converter including means to sense the current output, a current reference signal source, means to compare the current output sensed by said means to sense the current output with the signal of said current reference signal source, and means responsive to said means to compare to control the current output of said converter wherein the improvement comprises means to monitor the voltage output of said converter, a voltage reference signal source, means to disable said means to compare when the voltage detected by said means to monitor the voltage output decreases below the signal of said voltage reference signal source, a first operational amplifier connected as an amplifier to detect the current in said means to sense the current output, an overcurrent reference signal source, a second operational amplifier responsive to said first operational amplifier and said overcurrent reference signal source, said second operational amplifier generating a signal in response to an overcurrent, and means responsive to said second operational amplifier to disconnect said converter from said output.
Claim 9
Dependent Claim
138 words
A DC to DC converter as defined in claim 5 wherein said output includes filter capacitor and wherein the improvement further comprises a third operational amplifier connected as an amplifier to detect the current in said means to sense the current output, a second means to sense current connected in series with said filter capacitor, a fourth operational amplifier connected as an amplifier to detect the current in said second means to sense current, a fifth operational amplifier connected as an amplifier, a reverse current reference signal source connected to said fifth operational amplifier to establish a signal response threshold, means to couple the output of said third and fourth operational amplifiers to said fifth operational amplifier and said means resPonsive to disconnect said converter from said output being responsive to the output of said fifth operational amplifier.
Claim 10
Dependent Claim
31 words
A DC to DC converter as defined in claim 6 wherein the improvement further comprises means included in said second and fifth operational amplifiers to delay a response to input signals.
Claim 11
Dependent Claim
28 words
A DC to DC converter as defined in claim 5 wherein said means to disable comprises a clamping means connected to the input of said means to compare.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-04-15 | 1977-10-15 | 1978-04-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-04-15 | 1981-10-15 | 1982-04-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-04-15 | 1985-10-15 | 1986-04-16 | $7700.00 | Window Closed / Lapsed |