Patent US4424558A successfully refreshed from Google Patents.
US4424558A
Expired / Lapsed
US
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Freely commutating chopper circuit
Assignee: Compagnie Electro Mecanique SA
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Filing: 1981-07-17
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Granted: 1984-01-03
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Expires: 2001-07-17
Abstract
Abstract The invention relates to a chopper circuit with free commutation for the supply of power to a load from a source of direct current. It comprises a principal thyristor with a return diode, a series resonant circuit as the commutation circuit and a free-wheeling diode. The free-wheeling diode is parallel to the capacitor of the resonant circuit so that the coil serves both as the commutation circuit and the coil to limit variations of the current in the thyristor. The circuit is particularly suitable for use with electric traction motors.
Inventors
- 👤 N'Guyen U. Thuy
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 08:47
CPC Classifications
H; H02; H02M; H02M3/00; H02M3/02; H02M3/04; H02M3/10; H02M3/125; H02M3/135
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
113 words
A freely commutating chopper circuit for the supply of power to a load from a source of direct current, comprising a principal thyristor; a return diode connected in reverse parallel relationship with said thyristor; a series resonant commutation circuit connected in parallel with the load; and a free-wheeling diode connected in parallel with a capacitor of the series resonant circuit and in series with a coil of said resonant circuit, so that said coil conducts both the commutation current and at least a major portion of the free-wheeling current and thereby serves both as the commutation coil in the resonant circuit and the coil limiting variations of the current in said principal thyristor.
Claim 2
Dependent Claim
113 words
A freely commutating chopper circuit for the supply of power to a load from a source of direct current, comprising a principal thyristor; a return diode connected in reverse parallel relationship with said thyristor; a series resonant commutation circuit connected in parallel with the load; and a free-wheeling diode connected in parallel with a capacitor of the series resonant circuit and in series with a coil of said resonant circuit, so that said coil conducts both the commutation current and at least a major portion of the free-wheeling current and thereby serves both as the commutation coil in the resonant circuit and the coil limiting variations of the current in said principal thyristor.
Claim 3
Dependent Claim
136 words
A freely commutating chopper circuit for the supply of power to a load from a source of direct current, comprising a principal thyristor; a return diode connected in reverse parallel relationship with said thyristor; a series resonant commutation circuit connected in parallel with the load; a free-wheeling diode connected in parallel with a capacitor of the series resonant circuit and in series with a coil of said resonant circuit, so that said coil serves both as the commutation coil in the resonant circuit and the coil limiting variations of the current in said principal thyristor; a second thyristor connected in reverse parallel relationship to said return diode; and an auxiliary diode connected between the junction of the principal thyristor and the coil, and the junction of the second thyristor with the return diode and the load.
Claim 4
Dependent Claim
136 words
A freely commutating chopper circuit for the supply of power to a load from a source of direct current, comprising a principal thyristor; a return diode connected in reverse parallel relationship with said thyristor; a series resonant commutation circuit connected in parallel with the load; a free-wheeling diode connected in parallel with a capacitor of the series resonant circuit and in series with a coil of said resonant circuit, so that said coil serves both as the commutation coil in the resonant circuit and the coil limiting variations of the current in said principal thyristor; a second thyristor connected in reverse parallel relationship to said return diode; and an auxiliary diode connected between the junction of the principal thyristor and the coil, and the junction of the second thyristor with the return diode and the load.
Claim 5
Dependent Claim
22 words
A chopper circuit according to claim 2, further comprising a discharge circuit in parallel with the capacitor of the series resonant circuit.
Claim 6
Dependent Claim
26 words
A chopper circuit according to claim 3, wherein the discharge circuit for the capacitor comprises an auxiliary thyristor, a coil and a resistance connected in series.
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) | 1987-01-02 | 1987-07-04 | 1988-01-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-01-02 | 1991-07-04 | 1992-01-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-01-02 | 1995-07-04 | 1996-01-03 | $7700.00 | Window Closed / Lapsed |