US3714512A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Protection circuit for transistor modulators
Assignee: General Electric Co
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Filing: 1972-04-06
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Granted: 1973-01-30
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Expires: 1992-04-06
Abstract
Abstract A load circuit is controlled by a darlington pair, which in turn is controlled by a transistor sensing circuit. A further transistor is provided in the sensing circuit to sense the current flow to the load. When excess current is flowing to the load this additional transistor will cause the sensing circuit to turn the darlington pair off, therefore limiting the amount of current flow to the load.
Inventors
- 👤 S Grabowski
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 04:43
CPC Classifications
G; G05; G05F; G05F1/00; G05F1/10; G05F1/46; G05F1/56; G05F1/565; G05F1/569; G05F1/573
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
256 words
A circuit for controlling current and voltage applied to a load comprising a direct current voltage source; current sensing means, composite transistor regulator means and load means serially connected to said voltage source; protection circuit means connected intermediate said voltage source and said regulator means, said protection circuit means including a first transistor and a second transistor, the collector electrode of said first transistor connected to the input of said composite transistor regulator means, the collector electrode of said second transistor connected to the base of said first transistor, the emitter electrodes of said first and second transistors connected to said voltage source, a voltage divider connected across said voltage source between said current sensing means and said regulator means, the base of said second transistor connected to said voltage divider; control circuit means including positive pulse means, a Zener diode, a transistor and resistor means serially connected to the base electrode of said first transistor, biasing means connected to the input of said composite transistor regulator means and diode means connected between the emitter electrodes of said composite transistor regulator means and the input of said composite transistor regulator means, said positive pulse means controlling conduction of said first transistor under normal current and voltage conditions to said load, said current sensing means and said voltage divider controlling conduction of said second transistor under abnormal conditions of current and voltage to said load to prevent conduction of said first transistor and said composite transistor regulator means thereby cutting off current and voltage to said load.
Claim 2
Dependent Claim
256 words
A circuit for controlling current and voltage applied to a load comprising a direct current voltage source; current sensing means, composite transistor regulator means and load means serially connected to said voltage source; protection circuit means connected intermediate said voltage source and said regulator means, said protection circuit means including a first transistor and a second transistor, the collector electrode of said first transistor connected to the input of said composite transistor regulator means, the collector electrode of said second transistor connected to the base of said first transistor, the emitter electrodes of said first and second transistors connected to said voltage source, a voltage divider connected across said voltage source between said current sensing means and said regulator means, the base of said second transistor connected to said voltage divider; control circuit means including positive pulse means, a Zener diode, a transistor and resistor means serially connected to the base electrode of said first transistor, biasing means connected to the input of said composite transistor regulator means and diode means connected between the emitter electrodes of said composite transistor regulator means and the input of said composite transistor regulator means, said positive pulse means controlling conduction of said first transistor under normal current and voltage conditions to said load, said current sensing means and said voltage divider controlling conduction of said second transistor under abnormal conditions of current and voltage to said load to prevent conduction of said first transistor and said composite transistor regulator means thereby cutting off current and voltage to said load.
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) | 1976-01-30 | 1976-07-31 | 1977-01-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-01-30 | 1980-07-31 | 1981-01-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-01-30 | 1984-07-31 | 1985-01-30 | $7700.00 | Window Closed / Lapsed |