Patent US3829708A successfully refreshed from Google Patents.
US3829708A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Transistor switching circuit arrangement for an inductive d-c circuit
Assignee: Siemens AG
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Filing: 1972-07-12
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Granted: 1974-08-13
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Expires: 1992-07-12
Abstract
Abstract A transistor circuit arrangement for switching an inductive d-c circuit on and off is disclosed in which ''''secondary'''' breakdown of the transistor switch is prevented. The breakdown is caused by excess voltage at the transistor during the disconnecting of the inductive circuit. To prevent this, an integrating element, whose charging and discharging circuits are decoupled, is arranged between the collector and the base of a transistor. This permits the controlled charging of the integrator when the inductor is disconnected and an approximately constant voltage rise at the collector-emitter of the transistor.
Inventors
- 👤 H Grunleitner
- 👤 H Kuhnlein
- 👤 M Liska
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 23:23
CPC Classifications
H; H03; H03K; H03K17/00; H03K17/51; H03K17/56; H03K17/60; H03K17/64; H03K17/08; H03K17/082; H03K17/0826
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
171 words
A circuit for switching an inductive d-c load on and off using a transistor switch so as to avoid secondary breakdown of the transistor due to high transient voltages generated by the load comprising: a. a transistor switch having its emitter-collector path in series with the load across a d-c source; b. a capacitor connected between the base and collector of said transistor; c. a first resistor coupling said base to one side of the d-c source; d. a second resistor having its one end connected to the other side of said source and its other end connected through a switch to said one side of said source, the value of said second resistor being substantially greater than that of said first resistor; e. a diode connecting the junction of said second resistor and said switch to said base having a polarity such as to permit said capacitor to be charged through said first resistor when said switch is open and discharged through said second resistor when said switch is closed.
Claim 2
Dependent Claim
171 words
A circuit for switching an inductive d-c load on and off using a transistor switch so as to avoid secondary breakdown of the transistor due to high transient voltages generated by the load comprising: a. a transistor switch having its emitter-collector path in series with the load across a d-c source; b. a capacitor connected between the base and collector of said transistor; c. a first resistor coupling said base to one side of the d-c source; d. a second resistor having its one end connected to the other side of said source and its other end connected through a switch to said one side of said source, the value of said second resistor being substantially greater than that of said first resistor; e. a diode connecting the junction of said second resistor and said switch to said base having a polarity such as to permit said capacitor to be charged through said first resistor when said switch is open and discharged through said second resistor when said switch is closed.
Claim 3
Dependent Claim
66 words
A circuit for switching an inductive d-c circuit on and off as in claim 1 in which an auxiliary adjustable voltage source is arranged between the first resistor and the one side of the d-c voltage source to permit the adjustment of the voltage applied to the transistor with varying starting currents when the transistor is turned on and the inductive d-c circuit is turned on.
Claim 4
Dependent Claim
194 words
A circuit for switching an inductive d-c load on and off using a transistor switch so as to avoid secondary breakdown of the transistor due to high transient voltages generated by the load comprising: a. a transistor switch having its emitter-collector path in series with the load across a d-c source; b. an amplifier transistor having its emitter coupled to the base of said transistor switch and its collector coupled to said source; c. a capacitor connected between the base and collector of said amplifier transistor; d. a first resistor coupling said base to one side of the d-c source; e. a second resistor having its one end connected to the other side of said source and its other end connected through a switch to said one side of said source, the value of said second resistor being substantially greater than that of said first resistor; f. a diode connecting the junction of said second resistor and said switch to said base having a polarity such as to permit said capacitor to be charged through said first resistor when said switch is open and discharged through said second resistor when said switch is closed.
Claim 5
Dependent Claim
194 words
A circuit for switching an inductive d-c load on and off using a transistor switch so as to avoid secondary breakdown of the transistor due to high transient voltages generated by the load comprising: a. a transistor switch having its emitter-collector path in series with the load across a d-c source; b. an amplifier transistor having its emitter coupled to the base of said transistor switch and its collector coupled to said source; c. a capacitor connected between the base and collector of said amplifier transistor; d. a first resistor coupling said base to one side of the d-c source; e. a second resistor having its one end connected to the other side of said source and its other end connected through a switch to said one side of said source, the value of said second resistor being substantially greater than that of said first resistor; f. a diode connecting the junction of said second resistor and said switch to said base having a polarity such as to permit said capacitor to be charged through said first resistor when said switch is open and discharged through said second resistor when said switch is closed.
Claim 6
Dependent Claim
66 words
A circuit for switching an inductive d-c circuit on and off as in claim 3 in which an auxiliary adjustable voltage source is arranged between the first resistor and the one side of the d-c voltage source to permit the adjustment of the voltage applied to the transistor with varying starting currents wheN the transistor is turned on and the inductive d-c circuit is turned on.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-08-12 | 1978-02-11 | 1978-08-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-08-12 | 1982-02-11 | 1982-08-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-08-12 | 1986-02-11 | 1986-08-13 | $7700.00 | Window Closed / Lapsed |