US3641409A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Control system for dc motor
Assignee: Okuma Corp
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Filing: 1969-10-08
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Granted: 1972-02-08
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Expires: 1989-10-08
Abstract
Abstract A control system for controlling a DC motor by controlling the conduction angle of controllable electric valves, wherein in order to discharge energy stored in a choke coil connected in series with the armature of the DC motor, the controllable electric valves including rectifiers are connected in parallel with the series circuit of the DC motor and choke coil for the control of unidirectional rotation, and a reverse parallel circuit consisting of controllable electric valves is connected in parallel with said series circuit for the reversible control.
Inventors
- 👤 Yutaka Maeda
- 👤 Kinya Hirata
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 23:23
CPC Classifications
G; G05; G05D; G05D3/00; G05D3/12; G05D3/14; G05D3/18; H; H02; H02P; H02P7/00; H02P7/06; H02P7/18; H02P7/24; H02P7/28; H02P7/285; H02P7/292; H02P7/293
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
135 words
In a speed control system for a DC motor being supplied with AC power comprising an armature rectifying means to convert the AC power to DC power by energizing the rectifying means at a conduction angle to produce DC power having a selectEd polarity, and means for determining the polarity of said DC power and changing the conduction angle, the improvement comprising a choke coil connected between said rectifying means and said armature of said DC motor, a discharging circuit including a pair of controlled rectifiers connected in parallel and in opposite conducting directions, said discharging circuit being connected in parallel across said armature and said choke coil, and means for controlling said discharging circuit to selectively make one of said controlled rectifiers conductive in accordance with the direction of rotation of said DC motor.
Claim 2
Dependent Claim
135 words
In a speed control system for a DC motor being supplied with AC power comprising an armature rectifying means to convert the AC power to DC power by energizing the rectifying means at a conduction angle to produce DC power having a selectEd polarity, and means for determining the polarity of said DC power and changing the conduction angle, the improvement comprising a choke coil connected between said rectifying means and said armature of said DC motor, a discharging circuit including a pair of controlled rectifiers connected in parallel and in opposite conducting directions, said discharging circuit being connected in parallel across said armature and said choke coil, and means for controlling said discharging circuit to selectively make one of said controlled rectifiers conductive in accordance with the direction of rotation of said DC motor.
Claim 3
Dependent Claim
47 words
A speed control system according to claim 1, comprising means for generating a repetitive gate signal while said motor rotates in one direction, said repetitive gate signal being applied to a gate electrode of one of said pair of controlled rectifiers corresponding to said direction of rotation.
Claim 4
Dependent Claim
96 words
A speed control system according to claim 1, wherein said means for controlling said discharging includes a flip-flop having two stages, a pair of trigger circuits for producing a gate signal to make respective ones of said pair of controlled rectifiers conductive, each stage of said two stages having a trigger terminal and being connected to a respective one of said pair of trigger circuits, and one of said trigger terminals being selectively supplied with a trigger signal in phase with a signal produced by said means for controlling the conduction angle of said rectifying means.
Claim 5
Dependent Claim
46 words
A speed control system according to claim 3, wherein said trigger circuit comprises a pulse generating circuit for producing a pulse signal from the corresponding stage of said flip-flop, and a constant voltage rectifying circuit for producing said gate signal to make corresponding controlled rectifier conductive.
References Cited (Backward Citations)
US3372327A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-02-07 | 1975-08-09 | 1976-02-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-02-07 | 1979-08-09 | 1980-02-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-02-07 | 1983-08-09 | 1984-02-08 | $7700.00 | Window Closed / Lapsed |