Patent US3794885A successfully refreshed from Google Patents.
US3794885A
Expired / Lapsed
US
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Static type electric circuit breaker
Assignee: Toshiba Corp
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Filing: 1972-11-09
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Granted: 1974-02-26
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Expires: 1992-11-09
Abstract
Abstract A single-phase full-wave type rectifier bridge is respectively provided within selected phases of A.C. line conductors and in series therewith to provide for the switching of an A.C. load current. Each rectifier bridge has four arms two of which respectively include a main thyristor and the other two arms of which respectively include a main diode. Additionally, the rectifier bridge functions such that one of the main thyristors passes a positive half wave of current therethrough, the other main thyristor passes a negative half wave of current therethrough, one of the main diodes becomes conductive during a positive half wave of the current and the other of the main diodes becomes conductive during a negative half wave of the current. A reactor is connected across the D.C. output terminals of the rectifier bridge for conduction of the load current. A series combination of a commutating capacitor and an auxiliary thyristor is connected between an intermediate connection point of the main thyristors of the rectifier bridge and other terminals of the main thyristors through an auxiliary diode. The commutating capacitor is normally charged from an auxiliary D.C. voltage supply and is discharged to negatively bias the main thyristor which is conductive when the auxiliary thyristor is turned on when a circuit-interruption is required.
Inventors
- 👤 H Kishi
- 👤 K Takigami
- 👤 Y Shirasaka
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 04:55
CPC Classifications
H; H02; H02H; H02H3/00; H02H3/08
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
243 words
A static type electric circuit breaker comprising: a plurality of rectifier bridges each respectively being connected in selected phases of A.C. line conductors and in series therewith, each of said rectifier bridges having four arms two arms of which respectively include a main thyristor unit and the other two arms of which respectively include a main diode unit, one set of main thyristor units and said main diode units of each rectifier bridge allowing a positive half wave of A.C. current to pass therethrough and the other set of said main thyristor units and said main diode units of each bridge allowing a negative half wave of A.C. current to pass therethrough; a reactor connected across the D.C. output terminals of each of said rectifier bridges and allowing full waves of A.C. current to pass therethrough; means for commutating said main thyristor units, said means consisting of a series combination of a single commutating capacitor unit and a single auxiliary thyristor unit, said commutating capacitor unit being normally charged with a predetermined polarity from an auxiliary D. C. voltage supply, means for discharging electric charges of said commutating capacitor unit in a reverse polarity to those of said main thyristor units of each of said rectifier bridges which are conducting; and, a gate control circuit means for applying gate control signals to said main thyristor units of each of said rectifier bridges and for applying gate turn-off signals to said auxiliary thyristor unit.
Claim 2
Dependent Claim
243 words
A static type electric circuit breaker comprising: a plurality of rectifier bridges each respectively being connected in selected phases of A.C. line conductors and in series therewith, each of said rectifier bridges having four arms two arms of which respectively include a main thyristor unit and the other two arms of which respectively include a main diode unit, one set of main thyristor units and said main diode units of each rectifier bridge allowing a positive half wave of A.C. current to pass therethrough and the other set of said main thyristor units and said main diode units of each bridge allowing a negative half wave of A.C. current to pass therethrough; a reactor connected across the D.C. output terminals of each of said rectifier bridges and allowing full waves of A.C. current to pass therethrough; means for commutating said main thyristor units, said means consisting of a series combination of a single commutating capacitor unit and a single auxiliary thyristor unit, said commutating capacitor unit being normally charged with a predetermined polarity from an auxiliary D. C. voltage supply, means for discharging electric charges of said commutating capacitor unit in a reverse polarity to those of said main thyristor units of each of said rectifier bridges which are conducting; and, a gate control circuit means for applying gate control signals to said main thyristor units of each of said rectifier bridges and for applying gate turn-off signals to said auxiliary thyristor unit.
Claim 3
Dependent Claim
52 words
A static type electric circuit breaker according to claim 1, wherein: said discharging means of electric charges of said commutating capacitor unit includes a diode unit respectively connected between A. C. terminals of each of said rectifier bridges adjacent to an A. C. voltage supply and one terminal of said commutating means.
Claim 4
Dependent Claim
85 words
A static type electric circuit breaker according to claim 1, wherein: said discharging means of electric charges of said commutating capacitor unit include a first diode unit respectively connected between A. C. terminals of each of said rectifier bridges adjacent to an A. C. voltage supply and one terminal of said commutating means, and a second diode unit respectively connected between A. C. terminals of each of said rectifier bridges adjacent to an A. C. load and the same said terminal of said commutating means.
Claim 5
Dependent Claim
42 words
A static type electric circuit breaker according to claim 2, wherein: an auxiliary diode unit is respectively connected between a serially interconnected point of said main thyristor units of each of said rectifier bridges and the other terminal of said commutating means.
Claim 6
Dependent Claim
42 words
A static type electric circuit breaker according to claim 3, wherein: an auxiliary diode unit is respectively connected between a serially interconnected point of said main thyristor units of each of said rectifier bridges and the other terminal of said commutating means.
Claim 7
Dependent Claim
109 words
A static type electric circuit breaker according to claim 1, wherein: said gate control circuit means includes: an overcurrent detector for generating an output signal in response to a predetermined overcurrent condition of said A. C. line conductors and for applying said output signal to said auxiliary thyristor unit to make it turn on, a gate control for controlling the gate angle of said main thyristor units of each of said rectifier bridges, and a switching circuit for normally applying the control signal of said gate control to said main thyristor units of each of said rectifier bridges only when the output signal of said overcurrent detector is absent.
Claim 8
Dependent Claim
26 words
A static type electric circuit breaker according to claim 1 wherein one of said rectifier bridges is omitted from one of said A. C. line conductors.
Claim 9
Dependent Claim
251 words
A static type electric circuit breaker comprising: a rectifIer bridge connected to a line of a single-phase A.C. voltage supply, said rectifier bridge having four arms two arms of which respectively include a main thyristor unit and the other two arms of which respectively include a main diode unit, one set of said main thyristor units and said diode units permitting a positive half wave of A.C. current to pass therethrough and the other set of said main thyristor units and said diode units permitting a negative half wave of A. C. current to pass therethrough; a reactor connected across D.C. output terminals of said rectifier bridge and permitting full waves of A.C. current to pass therethrough; means for commutating said main thyristor units, said means consisting of a series combination of a single commutating capacitor unit and a single auxiliary thyristor unit, said commutating capacitor unit being normally charged with a predetermined polarity from an auxiliary D. C. voltage supply; means for discharging electric charges of said commutating capacitor through said main thyristor unit which is conducting in a reverse polarity thereto; a gate control for applying a gate control signal to said main thyristor units; an overcurrent detector for applying an output signal in response to a predetermined overcurrent condition of said A.C. lines to said auxiliary thyristor unit; and, a switching circuit for normally applying the control signal from said gate control to said main thyristor units only when the output signal of said overcurrent detector is absent.
Claim 10
Dependent Claim
251 words
A static type electric circuit breaker comprising: a rectifIer bridge connected to a line of a single-phase A.C. voltage supply, said rectifier bridge having four arms two arms of which respectively include a main thyristor unit and the other two arms of which respectively include a main diode unit, one set of said main thyristor units and said diode units permitting a positive half wave of A.C. current to pass therethrough and the other set of said main thyristor units and said diode units permitting a negative half wave of A. C. current to pass therethrough; a reactor connected across D.C. output terminals of said rectifier bridge and permitting full waves of A.C. current to pass therethrough; means for commutating said main thyristor units, said means consisting of a series combination of a single commutating capacitor unit and a single auxiliary thyristor unit, said commutating capacitor unit being normally charged with a predetermined polarity from an auxiliary D. C. voltage supply; means for discharging electric charges of said commutating capacitor through said main thyristor unit which is conducting in a reverse polarity thereto; a gate control for applying a gate control signal to said main thyristor units; an overcurrent detector for applying an output signal in response to a predetermined overcurrent condition of said A.C. lines to said auxiliary thyristor unit; and, a switching circuit for normally applying the control signal from said gate control to said main thyristor units only when the output signal of said overcurrent detector is absent.
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) | 1977-02-25 | 1977-08-27 | 1978-02-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-02-25 | 1981-08-27 | 1982-02-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-02-25 | 1985-08-27 | 1986-02-26 | $7700.00 | Window Closed / Lapsed |