US3560822A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Motor control having a feedback stablilized generator
Assignee: Reliance Electric Co
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Filing: 1968-09-06
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Granted: 1971-02-02
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Expires: 1988-09-06
Abstract
Abstract A variable voltage motor control wherein the hoist motor armature is supplied from a dynamoelectric machine having its characteristics linearized by a closed negative feedback loop including a controlled supply for its shunt field. The effective constant gain of the generator enhances operation particularly in elevator hoist motor controls.
Inventors
- 👤 Richard C Loshbough
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 07:52
CPC Classifications
H; H02; H02P; H02P7/00; H02P7/06; H02P7/18; H02P7/34
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
197 words
A motor control for a direct current motor comprising a motor armature, a direct current generator, a shunt field for said generator, an armature for said generator, means operative coupling said generator armature to said motor armature, means to generate a voltage which is a function of actual motor speed, means to generate a voltage which is a function of commanded motor speed, means differentially summing said commanded and actual motor speed voltages to develop a motor speed error signal, means generating a commanded generator armature voltage in response to said motor speed error signal, means sensing actual generator-armature voltage, means differentially summing said commanded and actual generator-armature voltages to develop a generator-armature error voltage, an amplifier between said motor speed signal summing means and said generator-armature voltage signal summing means, a controllable source of electrical energy connected to supply said generator shunt field, means controlling said controllable source in response to said error voltage, and means to reduce the gain of said amplifier while said motor is stopped and to increase the gain of said amplifier while said motor is set to run, whereby zero offset of said amplifier is minimized when said motor is stopped.
Claim 2
Dependent Claim
197 words
A motor control for a direct current motor comprising a motor armature, a direct current generator, a shunt field for said generator, an armature for said generator, means operative coupling said generator armature to said motor armature, means to generate a voltage which is a function of actual motor speed, means to generate a voltage which is a function of commanded motor speed, means differentially summing said commanded and actual motor speed voltages to develop a motor speed error signal, means generating a commanded generator armature voltage in response to said motor speed error signal, means sensing actual generator-armature voltage, means differentially summing said commanded and actual generator-armature voltages to develop a generator-armature error voltage, an amplifier between said motor speed signal summing means and said generator-armature voltage signal summing means, a controllable source of electrical energy connected to supply said generator shunt field, means controlling said controllable source in response to said error voltage, and means to reduce the gain of said amplifier while said motor is stopped and to increase the gain of said amplifier while said motor is set to run, whereby zero offset of said amplifier is minimized when said motor is stopped.
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) | 1974-02-01 | 1974-08-03 | 1975-02-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-02-01 | 1978-08-03 | 1979-02-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-02-01 | 1982-08-03 | 1983-02-02 | $7700.00 | Window Closed / Lapsed |