US3792341A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Power supply circuitry having base drive inhibit control
Assignee: Keithley Instruments LLC
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Filing: 1971-12-22
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Granted: 1974-02-12
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Expires: 1991-12-22
Abstract
Abstract A D.C. power supply circuit having a series semiconductor for supplying energizing current to a load in accordance with base drive current supplied thereto from a drive circuit. Base drive inhibiting means are interposed between the semiconductor and the base drive circuit for inhibiting base drive current as the output voltage decreases in magnitude below a desired level. Circuitry is also employed for controlling the drive means to alternately turn on and turn off the semiconductor means acting as a series switch in a switching regulator circuit, and output circuitry serves for providing clock pulses at a frequency dependent upon the switching frequency of the semiconductor means.
Inventors
- 👤 R Kime
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 03:51
CPC Classifications
H; H02; H02H; H02H7/00; H02H7/10; H02H7/12; H02H7/1213
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
218 words
An electrical circuit comprising a load circuit, means for supplying energizing current to said load circuit to obtain a load output voltage and including first transistor means having its emitter-collector circuit connected in series with a D.C. voltage source for supplying energizing current therethrough to said load circuit, drive means for providing base drive current flow for controlling the conductivity of said first transistor means, base drive inhibiting means including second transistor means having its emitter-collector path interposed between said drive means and said first transistor and connected in series with the emitter base circuit of said first transistor and circuit means for varying the conductivity of said second transistor means for presenting an increasingly higher impedance path to said base drive current as said output voltage decreases below a desired level, bias voltage supplying circuit means including switching means for supplying bias voltage from said voltage source through said switching means to said drive means to render same operative when said switching means is closed, and turn on circuit means connected to said bias voltage supply circuit means for supplying a turn on signal to the base of said second transistor means to provide an initial low impedance path to said base drive current when said driver means is operative to provide said base drive current flow.
Claim 2
Dependent Claim
218 words
An electrical circuit comprising a load circuit, means for supplying energizing current to said load circuit to obtain a load output voltage and including first transistor means having its emitter-collector circuit connected in series with a D.C. voltage source for supplying energizing current therethrough to said load circuit, drive means for providing base drive current flow for controlling the conductivity of said first transistor means, base drive inhibiting means including second transistor means having its emitter-collector path interposed between said drive means and said first transistor and connected in series with the emitter base circuit of said first transistor and circuit means for varying the conductivity of said second transistor means for presenting an increasingly higher impedance path to said base drive current as said output voltage decreases below a desired level, bias voltage supplying circuit means including switching means for supplying bias voltage from said voltage source through said switching means to said drive means to render same operative when said switching means is closed, and turn on circuit means connected to said bias voltage supply circuit means for supplying a turn on signal to the base of said second transistor means to provide an initial low impedance path to said base drive current when said driver means is operative to provide said base drive current flow.
Claim 3
Dependent Claim
57 words
An electrical circuit as set forth in claim 1 wherein said controlling circuit means includes base drive circuit means connecting the output load circuit with the base of said second transistor means in such a manner that as said output voltage decreases in magnitude said base drive circuit means tends to turn said seCond transistor means off.
Claim 4
Dependent Claim
40 words
An electrical circuit as set forth in claim 2 wherein said base drive circuit means includes a diode and a resistor connected together in a series circuit between the output load circuit and the base of said second transistor means.
Claim 5
Dependent Claim
40 words
An electrical circuit as set forth in claim 1 wherein said turn on circuit means includes delay means for delaying the supply of said turn on signal until said output voltage initially attains a level corresponding with said desired level.
Claim 6
Dependent Claim
40 words
An electrical circuit as set forth in claim 4 wherein said delay means includes a capacitor connected together in series with a resistor between said switching means for supplying said bias voltage and the base of said second transistor 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) | 1977-02-11 | 1977-08-13 | 1978-02-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-02-11 | 1981-08-13 | 1982-02-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-02-11 | 1985-08-13 | 1986-02-12 | $7700.00 | Window Closed / Lapsed |