Patent US3813591A successfully refreshed from Google Patents.
US3813591A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Dc motor speed control circuit
Assignee: General Electric Co
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Filing: 1973-03-06
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Granted: 1974-05-28
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Expires: 1993-03-06
Abstract
Abstract A d.c. motor control circuit of the type employing phase controlled semiconductor devices of the controlled rectifier type is provided with suitable feedback means respecting motor operation. A full wave controlled rectifier bridge supplies power to the motor armature winding from an a.c. source and means are provided for adjusting the phase angle of controlled rectifier firing in response to an error signal derived from true back emf of the motor.
Inventors
- 👤 E Dinger
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 04:33
CPC Classifications
H; H02; H02P; H02P7/00; H02P7/06; H02P7/18; H02P7/24; H02P7/28; H02P7/285; H02P7/292; H02P7/293; Y; Y10; Y10S; Y10S388/00; Y10S388/907; Y10S388/917; Y10S388/921
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
211 words
A speed control circuit for a direct current motor, having an armature winding and a field winding, operable from a source of alternating current input voltage, said control circuit comprising: a. a full wave bridge circuit for applying a rectified voltage from said source to said motor, said bridge circuit including a controlled rectifier in each leg thereof; b. means for phase controlling the rectifiers of said bridge circuit to vary the effective voltage applied to said motor; c. means for developing a speed signal proportional to the voltage across the armature winding of said motor; d. means to provide a reference signal proportional to a desired speed of said motor; e. means to combine said speed signal and said reference signal to develop an error signal proportional to the difference between the desired and the actual speed of said motor; f. means to provide a timing signal indicative of the absence of current in said armature winding; and, g. means responsive to said timing signal to apply said error signal to said means for phase controlling said rectifiers to effect a variation in the phase angle at which the bridge rectifiers are caused to conduct to thereby vary the effective voltage applied to said motor to vary the speed thereof.
Claim 2
Dependent Claim
211 words
A speed control circuit for a direct current motor, having an armature winding and a field winding, operable from a source of alternating current input voltage, said control circuit comprising: a. a full wave bridge circuit for applying a rectified voltage from said source to said motor, said bridge circuit including a controlled rectifier in each leg thereof; b. means for phase controlling the rectifiers of said bridge circuit to vary the effective voltage applied to said motor; c. means for developing a speed signal proportional to the voltage across the armature winding of said motor; d. means to provide a reference signal proportional to a desired speed of said motor; e. means to combine said speed signal and said reference signal to develop an error signal proportional to the difference between the desired and the actual speed of said motor; f. means to provide a timing signal indicative of the absence of current in said armature winding; and, g. means responsive to said timing signal to apply said error signal to said means for phase controlling said rectifiers to effect a variation in the phase angle at which the bridge rectifiers are caused to conduct to thereby vary the effective voltage applied to said motor to vary the speed thereof.
Claim 3
Dependent Claim
13 words
The invention in accordance with claim 1 wherein said controlled rectifiers are thyristors.
Claim 4
Dependent Claim
15 words
The invention in accordance with claim 1 wherein said direct current motor is shunt wound.
Claim 5
Dependent Claim
248 words
A speed control circuit for a direct current motor, including an armature winding and a field winding, operable from a single phase alternating current voltage supply comprising: supply comprising: a. a full wave rectifying bridge circuit connecting said motor to said supply for applying a rectified voltage to said motor, said bridge circuit including a controlled rectifier in each leg thereof; b. means for selectively rendering said rectifiers of said bridge circuit conductive by pairs and on a phase controlled basis such that a pair of thyristors is conductive during a portion of alternate half cycles of the voltage of said supply to vary the effective voltage applied to said motor; c. means for deriving a speeds signal proportional to the voltage across the armature winding of said motor; d. means for providing a reference signal proportional to a desired speed of said motor; e. means to compare said speed signal and said reference signal to derive an error signal having a magnitude and a direction representing the difference between the reference signal and the speed signal; f. means to provide a timing signal indicative of the absence of a current in said armature winding; and, g. switch means responsive to said timing signal for applying said error signal to aid means for rendering the controlled rectifiers conductive to effect a variation in the phase angle at which said rectifiers are rendered conductive to thereby vary the effective voltage applied to said motor to vary the speed thereof.
Claim 6
Dependent Claim
248 words
A speed control circuit for a direct current motor, including an armature winding and a field winding, operable from a single phase alternating current voltage supply comprising: supply comprising: a. a full wave rectifying bridge circuit connecting said motor to said supply for applying a rectified voltage to said motor, said bridge circuit including a controlled rectifier in each leg thereof; b. means for selectively rendering said rectifiers of said bridge circuit conductive by pairs and on a phase controlled basis such that a pair of thyristors is conductive during a portion of alternate half cycles of the voltage of said supply to vary the effective voltage applied to said motor; c. means for deriving a speeds signal proportional to the voltage across the armature winding of said motor; d. means for providing a reference signal proportional to a desired speed of said motor; e. means to compare said speed signal and said reference signal to derive an error signal having a magnitude and a direction representing the difference between the reference signal and the speed signal; f. means to provide a timing signal indicative of the absence of a current in said armature winding; and, g. switch means responsive to said timing signal for applying said error signal to aid means for rendering the controlled rectifiers conductive to effect a variation in the phase angle at which said rectifiers are rendered conductive to thereby vary the effective voltage applied to said motor to vary the speed thereof.
Claim 7
Dependent Claim
13 words
The invention in accordance with claim 4 wherein said controlled rectifiers are thyristors.
Claim 8
Dependent Claim
15 words
The invention in accordance with claim 4 wherein said direct current motor is shunt wound.
References Cited (Backward Citations)
US3504260A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-05-27 | 1977-11-26 | 1978-05-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-05-27 | 1981-11-26 | 1982-05-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-05-27 | 1985-11-26 | 1986-05-28 | $7700.00 | Window Closed / Lapsed |