Patent US4175250A successfully refreshed from Google Patents.
US4175250A
Expired / Lapsed
US
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Transistor bias circuit
Assignee: Bunker Ramo Corp
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Filing: 1978-03-31
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Granted: 1979-11-20
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Expires: 1998-03-31
Abstract
Abstract A constant bias voltage and current for a transistor is provided by two series resistors connected across the transistor with a voltage regulator connected to a source of DC voltage for maintaining a predetermined voltage across the one resistor connected to the output electrode (drain or collector) of the transistor. The common electrode (source or emitter) is connected to a source of constant current.
Inventors
- 👤 Denny E. Morgan
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 11:00
CPC Classifications
G; G05; G05F; G05F1/00; G05F1/10; G05F1/46; G05F1/56
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
173 words
A circuit for providing a constant bias voltage and current for a transistor having a common electrode, an output electrode, and a control electrode adapted to receive a signal input, said circuit comprising a source of direct current voltage, two resistors in series between said common electrode and output electrode of said transistor, a first series resistor connected to said output electrode and a second series resistor connected to said common electrode of said transistor, voltage regulating means connected to said source of direct current voltage for maintaining a predetermined voltage across said first resistor of said two resistors connected in series to the output electrode, thereby to produce a first constant current through said first resistor, and means for providing a second constant current connected to said common electrode of said transistor, thereby to maintain a desired bias current through said transistor that is equal to the difference between said first and second constant currents while maintaining a constant bias voltage across the transistor from the output electrode to the common electrode.
Claim 2
Dependent Claim
173 words
A circuit for providing a constant bias voltage and current for a transistor having a common electrode, an output electrode, and a control electrode adapted to receive a signal input, said circuit comprising a source of direct current voltage, two resistors in series between said common electrode and output electrode of said transistor, a first series resistor connected to said output electrode and a second series resistor connected to said common electrode of said transistor, voltage regulating means connected to said source of direct current voltage for maintaining a predetermined voltage across said first resistor of said two resistors connected in series to the output electrode, thereby to produce a first constant current through said first resistor, and means for providing a second constant current connected to said common electrode of said transistor, thereby to maintain a desired bias current through said transistor that is equal to the difference between said first and second constant currents while maintaining a constant bias voltage across the transistor from the output electrode to the common electrode.
Claim 3
Dependent Claim
33 words
A circuit as defined in claim 1 wherein said transistor is a field-effect transistor and said common output and control electrodes are the source, drain and gate electrodes, respectively, of said field-effect transistor.
Claim 4
Dependent Claim
33 words
A circuit as defined in claim 1 wherein said transistor is a bipolar transistor and said common output and control electrodes are the emitter, collector and base electrodes, respectively, of said bipolar transistor.
Claim 5
Dependent Claim
59 words
A circuit as defined in claim 1 wherein said voltage regulating means is a 3-terminal feedback voltage regulator having an input terminal connected to said source of direct current voltage, an output terminal connected to said output terminal of said transistor and a control terminal, said control terminal being connected to the regulator output terminal by said first resistor.
Claim 6
Dependent Claim
34 words
A circuit as defined in claim 1 connected in cascade with a like circuit by connecting the output terminal of the transistor in one to the control terminal of the transistor in the other.
References Cited (Backward Citations)
US4042843A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1982-11-19 | 1983-05-21 | 1983-11-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-11-19 | 1987-05-21 | 1987-11-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-11-19 | 1991-05-21 | 1991-11-20 | $7700.00 | Window Closed / Lapsed |