US3697807A
Expired / Lapsed
US
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Bipolar circuit device
Assignee: Robert Bosch GmbH
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Filing: 1969-12-19
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Granted: 1972-10-10
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Expires: 1989-12-19
Abstract
Abstract A protective arrangement in which a bipolar circuit device is connected across the terminals of a voltage source with voltage monitored through a voltage regulator connected to the source. The bipolar device contains two transistors of opposite conductivity type interconnected so as to exhibit low internal resistance when the output voltage from the source lies within predetermined operating limits. When the output voltage from the source exceeds a predetermined limit, due to failure of the voltage regulator, for example, the internal resistance of the bipolar device drops sharply and substantially short-circuits the terminals of the generator. The change in resistance is made permanent through destruction of the transistors as a result of heat dissipation.
Inventors
- 👤 Klaus H Christ
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 11:42
CPC Classifications
H; H03; H03K; H03K17/00; H03K17/51; H03K17/56; H03K17/72; H03K17/73; H02; H02H; H02H9/00; H02H9/04; H02H9/041; H02J; H02J7/00; H02J7/14; H02J7/60; H02J7/64; H03K17/60; H02J7/80
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
151 words
A bipolar circuit device comprising, in combination, a source of voltage applied across two terminals of said source; two bipolar transistors interconnected across said two terminals and having a substantially high internal resistance when said voltage lies within predetermined operating limits, the internal resistance of said bipolar transistors being substantially decreased permanently when said voltage exceeds a predetermined limit, and wherein the interconnection between said two bipolar transistors does not include an external connection between the bases of said two bipolar transistors, the switching path of a first one of said transistors being connected in series with the control path of the second one of said transistors, the series combination of said switching path and said control path being connected across said two terminals of said source; and means with voltage breakdown characteristics connected between one of said terminals of said source and the control terminal of one of said transistors.
Claim 2
Dependent Claim
151 words
A bipolar circuit device comprising, in combination, a source of voltage applied across two terminals of said source; two bipolar transistors interconnected across said two terminals and having a substantially high internal resistance when said voltage lies within predetermined operating limits, the internal resistance of said bipolar transistors being substantially decreased permanently when said voltage exceeds a predetermined limit, and wherein the interconnection between said two bipolar transistors does not include an external connection between the bases of said two bipolar transistors, the switching path of a first one of said transistors being connected in series with the control path of the second one of said transistors, the series combination of said switching path and said control path being connected across said two terminals of said source; and means with voltage breakdown characteristics connected between one of said terminals of said source and the control terminal of one of said transistors.
Claim 3
Dependent Claim
55 words
The bipolar circuit device as defined in claim 1 wherein the switching path of a first one of said transistors is connected in series with the control path of the second one of said transistors, the series combination of said switching path and said control path being connected across said two terminals of said source.
Claim 4
Dependent Claim
46 words
The bipolar circuit device as defined in claim 1 wherein the base of the first one of said transistors is connected to the collector of the second one of said transistors, the base of said second transistor being connected to the collector of said first transistor.
Claim 5
Dependent Claim
52 words
The bipolar circuit device as defined in claim 2 wherein said first transistor is of the pnp type with emitter connected to the first one of said terminals of said source, said second transistor being of the pnp type with emitter connected to the second one of said terminals of said source.
Claim 6
Dependent Claim
20 words
The bipolar circuit device as defined in claim 1 wherein said means with voltage breakdown characteristics comprises a zener diode.
Claim 7
Dependent Claim
43 words
The bipolar circuit device as defined in claim 5 wherein the anode of said zener diode is connected to the emitter of one of said transistors, the cathode of said zener diode being connected to the collector of said one of said transistors.
Claim 8
Dependent Claim
25 words
The bipolar circuit device as defined in claim 6 including a resistor connected between the base and emitter of the other one of said transistors.
Claim 9
Dependent Claim
43 words
The bipolar circuit device as defined in claim 5 wherein the cathode of said zener diode is connected to the emitter of one of said transistors, the anode of said zener diode being connected to the collector of said one of said transistors.
Claim 10
Dependent Claim
25 words
The bipolar circuit device as defined in Claim 8 including resistor means connected between the base and the emitter of said one of said transistors.
Claim 11
Dependent Claim
32 words
The bipolar circuit device as defined in claim 1 including voltage regulating means connected to said terminals of said source for regulating said source, said source being a generator with excitation winding.
Claim 12
Dependent Claim
17 words
The bipolar circuit device as defined in claim 10 wherein said generator is an alternating current generator.
Claim 13
Dependent Claim
26 words
The bipolar circuit device as defined in claim 1 wherein said internal resistance is decreased permanently through heat dissipation when said voltage exceeds said predetermined limit.
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) | 1975-10-10 | 1976-04-10 | 1976-10-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-10-10 | 1980-04-10 | 1980-10-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-10-10 | 1984-04-10 | 1984-10-10 | $7700.00 | Window Closed / Lapsed |