US3753079A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Foldback current limiter
Assignee: Individual
•
Filing: 1972-03-08
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Granted: 1973-08-14
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Expires: 1992-03-08
Abstract
Abstract A diode providing a current that is an exponential function of the voltage applied across it is inserted in a series circuit carrying the output current of a current limiting device in which the voltage across the diode is reduced upon a short circuit taking place at an output terminal. This reduction in voltage severely limits the current through the diode at an exponential rate thereby affecting a sharp reduction in the short circuit current.
Inventors
- 👤 T Trilling
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 00:33
CPC Classifications
G; G05; G05F; G05F1/00; G05F1/10; G05F1/46; G05F1/56; G05F1/565; G05F1/569; G05F1/573; G05F1/5735
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
175 words
A voltage regulator having foldback current limiting characteristics comprising: power supply means for providing an output of constant voltage when the current is below a predetermined level; first reduction means including a serially connected diode and resistor connected at one end to receive the output of said power supply means and having a nonlinear voltage-current characteristic for providing a current output at an output terminal connected to the other end of said serially connected diode and resistor which decreases at a more rapid rate than its voltage, said output further providing a feedback signal to said power supply means; and second reduction means connected to receive the outputs of said power supply means and said first reduction means including a voltage divider circuit connected to said one end of said serially connected diode and resistor, and control means connected to said voltage divider circuit, for providing a feedback to said power suply means for substantially reducing the voltage and current from said power supply means when said power supply means current exceeds said predetermined level.
Claim 2
Dependent Claim
175 words
A voltage regulator having foldback current limiting characteristics comprising: power supply means for providing an output of constant voltage when the current is below a predetermined level; first reduction means including a serially connected diode and resistor connected at one end to receive the output of said power supply means and having a nonlinear voltage-current characteristic for providing a current output at an output terminal connected to the other end of said serially connected diode and resistor which decreases at a more rapid rate than its voltage, said output further providing a feedback signal to said power supply means; and second reduction means connected to receive the outputs of said power supply means and said first reduction means including a voltage divider circuit connected to said one end of said serially connected diode and resistor, and control means connected to said voltage divider circuit, for providing a feedback to said power suply means for substantially reducing the voltage and current from said power supply means when said power supply means current exceeds said predetermined level.
Claim 3
Dependent Claim
20 words
A voltage regulator having foldback curent limiting characteristics according to claim 1 wherein said control means comprises an NPN transistor.
Claim 4
Dependent Claim
78 words
A voltage regulator having foldback current limiting characteristics according to claim 2 wherein said power supply means further comprises: signal means for providing an output signal; and a Darlington circuit connected to said signal means for amplifying said output signal for providing said constant voltage when supplying said current beneath said predetermined level and further connected to said first reduction means for having the amplification controlled by said second reduction means when said current exceeds said predetermined level.
Claim 5
Dependent Claim
80 words
A voltage regulator having foldback current limiting characteristics according to claim 3 wherein said signal means further comprises: a differential amplifier having an inverting and a noninverting input terminals adapted to receive a bias signal on said noninverting terminal for supplying an output signal indicative of the signals applied to said input terminals; and a voltage divider circuit connected to said output terminal for feeding back a portion of the voltage on said output terminal to said inverting input terminal.
Claim 6
Dependent Claim
95 words
A voltage regulator having foldback current limiting characteristics according to claim 4 wherein said Darlington circuit further comprises: first, second and third transistors having collector electrodes connected in common with the base of said first transistor connected to receive said signal means output signal and further connected to the collector of said NPN transistor, the emitter of said first transistor connected to the base of said second transistor, the emitter of said second transistor connected to the base of said third transistor and the emitter of said third transistor connected to said first reduction means.
Claim 7
Dependent Claim
22 words
A voltage regulator having foldback current limiting characteristics according to claim 5 wherein said first, second and third transistors are NPN transistors.
Claim 8
Dependent Claim
51 words
A voltage regulator having foldback current limiting characteristics according to claim 6 further comprising temperature compensation means connected to said control means and to said diode for dissipating the heat generated with said control means and said diode and for keeping said diode and said control means at the same temperature.
Claim 9
Dependent Claim
31 words
A voltage regulator having foldback current limiting characteristics according to claim 7 wherein said temperature compensation means compRises a substrate of an integrated circuit comprising said diode and said control means.
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) | 1976-08-13 | 1977-02-12 | 1977-08-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-08-13 | 1981-02-12 | 1981-08-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-08-13 | 1985-02-12 | 1985-08-14 | $7700.00 | Window Closed / Lapsed |