US3599075A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Protections circuit for series connected solid state valves
Assignee: BBC Brown Boveri AG Germany
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Filing: 1969-11-04
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Granted: 1971-08-10
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Expires: 1989-11-04
Abstract
Abstract In a current-inverter arrangement of the type wherein a plurality of current-inverter valves, particularly thyristors, are connected in series, a pair of diodes of opposite polarity and a low-ohmic impedance unit are connected in series across each of at least some of the thyristors. The impedance unit is connected to the firing control electrode of the associated thyristor and the voltage drop produced across it in the event that a particular thyristor is not fired by a firing impulse regularly applied to its control electrode from a control transformer, provides an additional firing impulse for the thyristor.
Inventors
- 👤 Peter Etter
- 👤 Werner Faust
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 20:06
CPC Classifications
H; H02; H02M; H02M1/00; H02M1/08; H02M1/088
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
205 words
In a current-converter system, the combination comprising a chain of solid state valves of the controllable type connected electrically in series in a current flow path, means connected between the cathode and control electrode of each said valve for providing a firing pulse thereto, and a protective circuit for said series-connected valves comprising for each said valve a pair of oppositely poled avalanche diodes and a coupling diode connected in series between the anode side of the valve and the control electrode thereof, said pairs of oppositely poled avalanche diodes being connected directly in series and to the current flow path at opposite ends of the chain, and an impedance component individual to each said valve and which is connected at one terminal to the junction between the oppositely poled avalanche diodes correlated to said valve and the oppositely poled avalanche diodes for the adjacent valve in the chain and which is connected at its other terminal to the cathode side of said valve, said impedance component correlated to the last valve in the chain being included in the series circuit connection of said pairs of oppositely poled avalanche diodes which extends to said current flow path at the opposite end of said valve chain.
Claim 2
Dependent Claim
205 words
In a current-converter system, the combination comprising a chain of solid state valves of the controllable type connected electrically in series in a current flow path, means connected between the cathode and control electrode of each said valve for providing a firing pulse thereto, and a protective circuit for said series-connected valves comprising for each said valve a pair of oppositely poled avalanche diodes and a coupling diode connected in series between the anode side of the valve and the control electrode thereof, said pairs of oppositely poled avalanche diodes being connected directly in series and to the current flow path at opposite ends of the chain, and an impedance component individual to each said valve and which is connected at one terminal to the junction between the oppositely poled avalanche diodes correlated to said valve and the oppositely poled avalanche diodes for the adjacent valve in the chain and which is connected at its other terminal to the cathode side of said valve, said impedance component correlated to the last valve in the chain being included in the series circuit connection of said pairs of oppositely poled avalanche diodes which extends to said current flow path at the opposite end of said valve chain.
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) | 1974-08-09 | 1975-02-08 | 1975-08-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-08-09 | 1979-02-08 | 1979-08-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-08-09 | 1983-02-08 | 1983-08-10 | $7700.00 | Window Closed / Lapsed |