US3763418A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Single reactor force commutated chopper
Assignee: ABB Inc USA
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Filing: 1972-04-24
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Granted: 1973-10-02
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Expires: 1992-04-24
Abstract
Abstract A force commutated thyristor chopper is disclosed in which a single commutation inductor is coupled in the free-wheeling path of the chopper together with a free-wheeling diode. The single inductor provides a chopper of relatively simple configuration in which main and commutator thyristors couple a commutation capacitor to opposite ends of the commutation inductor, and a charging diode is coupled in parallel with the commutator thyristor to facilitate charging of the commutation capacitor in opposite senses. The resulting circuit arrangement operates in a highly effective and efficient manner, minimizes trapped energy and protects the various component parts thereof by preventing dangerously high current and voltage transients.
Inventors
- 👤 W Beck
- 👤 G Cardwell
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 07:26
CPC Classifications
H; H02; H02M; H02M3/00; H02M3/02; H02M3/04; H02M3/10; H02M3/125; H02M3/135
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
99 words
In a chopper circuit in which a plurality of controllably conductive devices coupled between a DC source and a load are selectively commutated to vary the voltage of the DC source as applied to the load and a current path accommodates free-wheeling current from the load during commutation, the improvement comprising a commutation inductor coupled in the free-wheeling current path, the commutation indicator cooperating with other parts of the chopper circuit to force-commutate at least one of the controllably conductive devices, the chopper circuit including at least two controllably conductive devices coupled to opposite ends of the commutation inductor.
Claim 2
Dependent Claim
99 words
In a chopper circuit in which a plurality of controllably conductive devices coupled between a DC source and a load are selectively commutated to vary the voltage of the DC source as applied to the load and a current path accommodates free-wheeling current from the load during commutation, the improvement comprising a commutation inductor coupled in the free-wheeling current path, the commutation indicator cooperating with other parts of the chopper circuit to force-commutate at least one of the controllably conductive devices, the chopper circuit including at least two controllably conductive devices coupled to opposite ends of the commutation inductor.
Claim 3
Dependent Claim
23 words
The invention defined in claim 1, wherein the chopper circuit includes a commutation capacitor coupled to the at least two controllably conductive devices.
Claim 4
Dependent Claim
74 words
In a chopper circuit in which at least a pair of thyristors are coupled between a DC source and a load, the improvement comprising an inductor coupled to both of the thyristors for limiting the rate of current increase in each of the thyristors whenever the thyristor is rendered conductive and a diode coupled to the inductor, the diode and the inductor being coupled to define a path for free-wheeling current from the load.
Claim 5
Dependent Claim
74 words
In a chopper circuit in which at least a pair of thyristors are coupled between a DC source and a load, the improvement comprising an inductor coupled to both of the thyristors for limiting the rate of current increase in each of the thyristors whenever the thyristor is rendered conductive and a diode coupled to the inductor, the diode and the inductor being coupled to define a path for free-wheeling current from the load.
Claim 6
Dependent Claim
64 words
In a chopper circuit in which at least one capacitor is bidirectionally charged to commutate a plurality of controllably conductive devices coupled between a DC source and a load, the improvement comprising an inductor coupled to pass current therethrough in one direction to effect charging of the at least one capacitor and to pass free-wheeling current from the load therethrough in an opposite direction.
Claim 7
Dependent Claim
64 words
In a chopper circuit in which at least one capacitor is bidirectionally charged to commutate a plurality of controllably conductive devices coupled between a DC source and a load, the improvement comprising an inductor coupled to pass current therethrough in one direction to effect charging of the at least one capacitor and to pass free-wheeling current from the load therethrough in an opposite direction.
Claim 8
Dependent Claim
141 words
A circuit for selectively applying signals from a DC source to a load, the DC source and the load each having first and second terminals, comprising a first thyristor coupled between the first terminals of the DC source and the load, a capacitor having one end thereof coupled to the first terminal of the DC source, an inductor having one end thereof coupled to the first terminal of the load, a second thyristor coupled between the end of the capacitor opposite said one end thereof and the end of the inductor opposite said one end thereof, means coupling the second terminals of the DC source and the load to complete a circuit between the DC source and the load and a diode coupled between the means coupling the second terminals and the end of the inductor opposite said one end thereof.
Claim 9
Dependent Claim
141 words
A circuit for selectively applying signals from a DC source to a load, the DC source and the load each having first and second terminals, comprising a first thyristor coupled between the first terminals of the DC source and the load, a capacitor having one end thereof coupled to the first terminal of the DC source, an inductor having one end thereof coupled to the first terminal of the load, a second thyristor coupled between the end of the capacitor opposite said one end thereof and the end of the inductor opposite said one end thereof, means coupling the second terminals of the DC source and the load to complete a circuit between the DC source and the load and a diode coupled between the means coupling the second terminals and the end of the inductor opposite said one end thereof.
Claim 10
Dependent Claim
17 words
The invention defined in claim 5, further including a diode coupled in parallel with the second thyristor.
Claim 11
Dependent Claim
67 words
A chopper circuit coupled between and controlling the application of a DC signal from a DC source to a load comprising a plurality of controllably conductive devices, and circuit means coupled across the load to provide a path for free-wheeling current and including inductive means, said inductive means also being coupled to each of the controllably conducted devices to aid in commutation of the controllably conductive devices.
Claim 12
Dependent Claim
67 words
A chopper circuit coupled between and controlling the application of a DC signal from a DC source to a load comprising a plurality of controllably conductive devices, and circuit means coupled across the load to provide a path for free-wheeling current and including inductive means, said inductive means also being coupled to each of the controllably conducted devices to aid in commutation of the controllably conductive devices.
Claim 13
Dependent Claim
35 words
The invention defined in claim 7, further including a capacitor coupled in circuit with the controllably conductive devices and the inductive means, said capacitor cooperating with the inductive means to commutate the controllably conductive devices.
Claim 14
Dependent Claim
53 words
A chopper circuit coupled between and controlling the application of a DC signal from a DC source to a load comprising the serial combination of an inductor and a diode coupled across the load, and a plurality of thyristors, each of which is coupled to be controlled by the inductor against transient overloads.
Claim 15
Dependent Claim
53 words
A chopper circuit coupled between and controlling the application of a DC signal from a DC source to a load comprising the serial combination of an inductor and a diode coupled across the load, and a plurality of thyristors, each of which is coupled to be controlled by the inductor against transient overloads.
Claim 16
Dependent Claim
51 words
A chopper circuit coupled between and controlling the application of a DC signal from a DC source to a load comprising a pair of thyristors, a capacitor and an inductor coupled to the thyristors to control commutation thereof, and a free-wheeling current path coupled to the load and including said inductor.
Claim 17
Dependent Claim
51 words
A chopper circuit coupled between and controlling the application of a DC signal from a DC source to a load comprising a pair of thyristors, a capacitor and an inductor coupled to the thyristors to control commutation thereof, and a free-wheeling current path coupled to the load and including said inductor.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-10-01 | 1977-04-02 | 1977-10-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-10-01 | 1981-04-02 | 1981-10-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-10-01 | 1985-04-02 | 1985-10-02 | $7700.00 | Window Closed / Lapsed |