US3593086A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Direct current motor circuits
Assignee: Linde Material Handling UK Ltd
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Filing: 1970-02-19
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Granted: 1971-07-13
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Expires: 1990-02-19
Abstract
Abstract A direct current motor circuit in which power in the motor is controlled by a main controllable rectifier whose condition is terminated by an auxiliary controllable rectifier fed with trigger signals alternately with the main rectifier. A winding coupled to a magnetic circuit inhibits the triggering of the auxiliary rectifier when the magnetic flux density in the magnetic circuit is high. The actual flux density is a balance between a flux produced by the field current of the motor, an opposing flux from an adjustable magnet and a flux produced by the armature current of the motor.
Inventors
- 👤 Duncan Ulick Thombs
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 17:24
CPC Classifications
H; H02; H02P; H02P7/00; H02P7/06; H02P7/18; H02P7/24; H02P7/28; H02P7/281; H02P7/282; Y; Y10; Y10S; Y10S388/00; Y10S388/907; Y10S388/913; Y10S388/917
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
159 words
A motor control circuit comprising a direct current motor having an armature circuit and a separate field circuit; and a current controller for the field circuit, said current controller comprising a controllable rectifier arranged as a power switch, said controllable rectifier being triggerable into conduction to allow a pulse of current to flow in the field circuit, extinguishing means triggerable to extinguish the conduction of the controllable rectifier, a pulse generator for providing trigger signals alternately for the controllable rectifier and the extinguishing means, a magnetic circuit, means for inhibiting the triggering of the extinguishing means when the flux density in the said magnetic circuit attains a predetermined value, adjustable control means for producing magnetic flux in the magnetic circuit, means for producing in the magnetic circuit an opposing magnetic flux in accord with the field current of the motor and means for producing magnetic flux in the magnetic circuit in accord with the armature current of the motor.
Claim 2
Dependent Claim
159 words
A motor control circuit comprising a direct current motor having an armature circuit and a separate field circuit; and a current controller for the field circuit, said current controller comprising a controllable rectifier arranged as a power switch, said controllable rectifier being triggerable into conduction to allow a pulse of current to flow in the field circuit, extinguishing means triggerable to extinguish the conduction of the controllable rectifier, a pulse generator for providing trigger signals alternately for the controllable rectifier and the extinguishing means, a magnetic circuit, means for inhibiting the triggering of the extinguishing means when the flux density in the said magnetic circuit attains a predetermined value, adjustable control means for producing magnetic flux in the magnetic circuit, means for producing in the magnetic circuit an opposing magnetic flux in accord with the field current of the motor and means for producing magnetic flux in the magnetic circuit in accord with the armature current of the motor.
Claim 3
Dependent Claim
39 words
A motor control circuit as claimed in claim 1 in which the means for producing the magnetic fluxes in accord with the field current and the armature current produce fluxes normally in opposition during the driving of the motor.
Claim 4
Dependent Claim
45 words
A motor control circuit as claimed in claim 2 in which an electrical impedance element responsive to the flux density in the magnetic circuit is disposed as a variable shunt between the pulse generator and the extinguishing means for inhibiting the passage of trigger signals.
Claim 5
Dependent Claim
62 words
A motor control circuit as claimed in claim 3 in which the means for producing the said magnetic fluxes in the magnetic circuit include windings arranged for energization by the armature current and the field current respectively; and in which a transductor constitutes said magnetic circuit, said transductor bearing the said windings and a further winding which constitutes the said impedance element.
Claim 6
Dependent Claim
143 words
A motor control circuit comprising a direct current motor having an armature circuit and a separate field circuit; and a current controller for the field circuit, said current controller comprising a main controllable rectifier arranged in series with said field circuit, a further controllable rectifier coupled in a commutating circuit with said main controllable rectifier, a pulse generator for provIding trigger signals alternately for the controllable rectifiers, a magnetic circuit, means for inhibiting the triggering of the further controllable rectifier when the flux density in the said magnetic circuit attains a predetermined value, adjustable control means for producing magnetic flux in the magnetic circuit, means for producing in the magnetic circuit an opposing magnetic flux in accord with the field current of the motor and means for producing magnetic flux in the magnetic circuit in accord with the armature current of the motor.
Claim 7
Dependent Claim
143 words
A motor control circuit comprising a direct current motor having an armature circuit and a separate field circuit; and a current controller for the field circuit, said current controller comprising a main controllable rectifier arranged in series with said field circuit, a further controllable rectifier coupled in a commutating circuit with said main controllable rectifier, a pulse generator for provIding trigger signals alternately for the controllable rectifiers, a magnetic circuit, means for inhibiting the triggering of the further controllable rectifier when the flux density in the said magnetic circuit attains a predetermined value, adjustable control means for producing magnetic flux in the magnetic circuit, means for producing in the magnetic circuit an opposing magnetic flux in accord with the field current of the motor and means for producing magnetic flux in the magnetic circuit in accord with the armature current of the motor.
Claim 8
Dependent Claim
79 words
A motor control circuit as claimed in claim 5 in which said magnetic circuit comprises a transductor and the said means for producing the said magnetic fluxes in the magnetic circuit include windings disposed on said transductor and in series with the armature circuit and the field circuit respectively; and in which a further winding on said transductor constitutes a variable shunt for inhibiting the passage of trigger signals between the pulse generator and the said further controllable rectifier.
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) | 1974-07-12 | 1975-01-11 | 1975-07-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-07-12 | 1979-01-11 | 1979-07-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-07-12 | 1983-01-11 | 1983-07-13 | $7700.00 | Window Closed / Lapsed |