Patent US3569742A successfully refreshed from Google Patents.
US3569742A
Expired / Lapsed
US
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Transistor switching circuit
Assignee: General Precision Systems Inc
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Filing: 1968-08-23
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Granted: 1971-03-09
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Expires: 1988-08-23
Abstract
Abstract A transistor switching circuit having a capacitor connected between a switching transistor and an input. A second transistor is provided to connect the capacitor to discharge in the reverse direction through the emitter base junction of the switching transistor to decrease its turning off time.
Inventors
- 👤 George F Schroeder
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 21:00
CPC Classifications
H; H03; H03K; H03K17/00; H03K17/04; H03K17/041; H03K17/0412; H03K17/04126; H03K17/51; H03K17/56; H03K17/60; H03K19/00; H03K19/02; H03K19/08; H03K19/082; H03K19/084
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
180 words
In an electrical circuit having at least one switching transistor connected to an input in a manner so that said switching transistor is turned on in response to a first input signal applied to said input and is turned off in response to a second input signal applied to said input and biasing means for applying a reverse bias across the emitter-base junction of said switching transistor, the improvement comprising switch means including a control electrode connected to said input to be driven thereby connected in the circuit between said biasing means and said switching transistor to prevent said reverse bias from being applied to said switching transistor when said first input signal is applied to said input and closing the circuit between said biasing means and said switching transistor to apply said reverse bias to said emitter-base junction when said second signal is applied to said input and unilaterally conducting means connected between said input and the junction between said biasing means and said switch means permitting current flow between said input and said junction only in one direction.
Claim 2
Dependent Claim
180 words
In an electrical circuit having at least one switching transistor connected to an input in a manner so that said switching transistor is turned on in response to a first input signal applied to said input and is turned off in response to a second input signal applied to said input and biasing means for applying a reverse bias across the emitter-base junction of said switching transistor, the improvement comprising switch means including a control electrode connected to said input to be driven thereby connected in the circuit between said biasing means and said switching transistor to prevent said reverse bias from being applied to said switching transistor when said first input signal is applied to said input and closing the circuit between said biasing means and said switching transistor to apply said reverse bias to said emitter-base junction when said second signal is applied to said input and unilaterally conducting means connected between said input and the junction between said biasing means and said switch means permitting current flow between said input and said junction only in one direction.
Claim 3
Dependent Claim
17 words
The improvement of claim 1 wherein said switch means is in the form of a second transistor.
Claim 4
Dependent Claim
72 words
The improvement as recited in claim 1 wherein said biasing means includes a capacitor, and wherein said unilaterally conducting means includes a diode connected in circuit with said capacitor to charge said capacitor while said first signal is applied to said input, and wherein said switch means and said diode cause said capacitor to discharge through said emitter-base junction of said switching transistor when said second signal is applied to said input.
Claim 5
Dependent Claim
15 words
The improvement as recited in claim 3 wherein said switch means comprises a second transistor.
Claim 6
Dependent Claim
57 words
The improvement as recited in claim 4 wherein said capacitor is connected between said input and said switching transistor and wherein the emitter and collector of said second transistor are connected in series with said capacitor across the emitter-base junction of said switching transistor, and wherein the base of said second transistor is connected to said input.
Claim 7
Dependent Claim
94 words
The improvement as recited in claim 1 wherein said biasing means comprises an impedance connected between said input and the emitter-base junction of said switching transistor and a capacitor connected across said impedance, and wherein said unilaterally conducting means includes a diode in circuit with said impedance, said capacitor and said input, and wherein said switch means comprises a second transistor having its emitter connected to the junction between said diode and said capacitor, having its base connected to said input and having its collector connected to the emitter-base junction of said switching transistor.
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) | 1974-03-08 | 1974-09-07 | 1975-03-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-03-08 | 1978-09-07 | 1979-03-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-03-08 | 1982-09-07 | 1983-03-09 | $7700.00 | Window Closed / Lapsed |