US3562616A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Control systems for electric motors
Assignee: Linde Material Handling UK Ltd
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Filing: 1969-01-07
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Granted: 1971-02-09
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Expires: 1989-01-07
Abstract
Abstract A motor drive circuit in which a direct current motor is fed with pulses of current by means of a controlled rectifier connected as a power switch between a power source and the motor. The conduction of the rectifier is controlled by a potential divider one element of which is a flux-responsive resistor adjacent a conductor of armature current. The divider is energized with a constant voltage thereby avoiding use of a freerunning pulse generator as a source of trigger pulses for the rectifier. A coil adjacent the resistor provides additional flux through the resistor for controlling the pulse rate of the motor.
Inventors
- 👤 Royston David Elliott
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 03:34
CPC Classifications
H; H02; H02P; H02P7/00; H02P7/06; H02P7/18; H02P7/24; H02P7/28; H02P7/285; H02P7/29; Y; Y10; Y10S; Y10S388/00; Y10S388/907; Y10S388/917; Y10S388/919
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
175 words
A motor drive circuit comprising a source of direct current, a direct current motor having armature and field, a controllable rectifier connected as a power switch between the source and the motor for energizing said motor with pulses of current in response to control pulses, said controllable rectifier having a control input, and a control circuit for feeding control pulses to said control input, the control circuit comprising: a triggerable pulse generating circuit having an output coupled to said control input and an input having a predetermined threshold level; a series combination of a magnetic flux-responsive resistor and a further resistor; direct current energizing means energizing said series combination with a steady voltage, the input of said triggerable pulse-generating circuit being coupled to the junction of said resistors; a conductor coupled to said armature and disposed adjacent the magnetic flux-responsive resistor for producing magnetic flux through said magnetic flux-responsive resistor in accord with the armature current of said motor; and means for varying the resistance of one of said resistors independently of said armature current.
Claim 2
Dependent Claim
175 words
A motor drive circuit comprising a source of direct current, a direct current motor having armature and field, a controllable rectifier connected as a power switch between the source and the motor for energizing said motor with pulses of current in response to control pulses, said controllable rectifier having a control input, and a control circuit for feeding control pulses to said control input, the control circuit comprising: a triggerable pulse generating circuit having an output coupled to said control input and an input having a predetermined threshold level; a series combination of a magnetic flux-responsive resistor and a further resistor; direct current energizing means energizing said series combination with a steady voltage, the input of said triggerable pulse-generating circuit being coupled to the junction of said resistors; a conductor coupled to said armature and disposed adjacent the magnetic flux-responsive resistor for producing magnetic flux through said magnetic flux-responsive resistor in accord with the armature current of said motor; and means for varying the resistance of one of said resistors independently of said armature current.
Claim 3
Dependent Claim
34 words
A motor drive circuit as set forth in claim 4 in which the adjustable means comprises a coil disposed adjacent the magnetic flux-responsive resistor and adjustable circuit means for feeding current through said coil.
Claim 4
Dependent Claim
19 words
A motor drive circuit as set forth in claim 4 in which the adjustable means comprises a permanent magnet.
Claim 5
Dependent Claim
35 words
A motor drive circuit as set forth in claim 1 in which said means for varying the resistance of one of said resistors comprises adjustable means for producing additional flux through said magnetic flux-responsive resistor.
References Cited (Backward Citations)
US3230436A
Cited
US3447056A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-02-08 | 1974-08-10 | 1975-02-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-02-08 | 1978-08-10 | 1979-02-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-02-08 | 1982-08-10 | 1983-02-09 | $7700.00 | Window Closed / Lapsed |