US4769581A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Circuit for controlling a brushless electric motor
Assignee: Deutsche Thomson Brandt GmbH
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Filing: 1986-04-22
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Granted: 1988-09-06
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Expires: 2006-04-22
Abstract
Abstract A circuit arrangement for controlling a brushless electric motor in which a control voltage derived from the rotor position is used to control the supply of line voltage to the stator winding of the motor. A control circuit which provides the control voltage is actuated several times over the areas intervals during one period of the line voltage, so that current pulses are applied to the stator winding for generating magnetic poles of opposite polarity to produce a rotating field with a frequency that is greater than the frequency of the line voltage.
Inventors
- 👤 Gerard Rilly
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 04:20
CPC Classifications
H; H02; H02K; H02K29/00; H02K29/03; H02P; H02P6/00; H02P6/08
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
131 words
A circuit for controlling a brushless electric motor having a permanent magnet rotor, a plurality of stator windings, and a rotor position sensor, comprising: a source of line voltage having a voltage frequency; control means for controlling the source of line voltage to said stator windings based on a control voltage derived from the rotor position sensor; said control means including a phase-control circuit connected to said source of line voltage and actuated, during one period of said line voltage, a plurality of times each having a predetermined interval to produce a plurality of voltage pulses, said phase-control circuit applying said voltage pulses to said stator windings to generate opposite magnetic poles in said motor for producing a rotating magnetic field with frequency higher than the frequency of said line voltage.
Claim 2
Dependent Claim
131 words
A circuit for controlling a brushless electric motor having a permanent magnet rotor, a plurality of stator windings, and a rotor position sensor, comprising: a source of line voltage having a voltage frequency; control means for controlling the source of line voltage to said stator windings based on a control voltage derived from the rotor position sensor; said control means including a phase-control circuit connected to said source of line voltage and actuated, during one period of said line voltage, a plurality of times each having a predetermined interval to produce a plurality of voltage pulses, said phase-control circuit applying said voltage pulses to said stator windings to generate opposite magnetic poles in said motor for producing a rotating magnetic field with frequency higher than the frequency of said line voltage.
Claim 3
Dependent Claim
34 words
A circuit as defined in claim 1, wherein said stator windings including two subsidiary windings of opposite polarity, said voltage pulses being supplied alternately to one subsidiary winding and to the other subsidiary winding.
Claim 4
Dependent Claim
96 words
A circuit as defined in claim 1, wherein said phase-control circuit includes an H-bridge circuit comprised of four switches supplied with said line voltage, said H-bridge circuit being formed by a first branch of two switches connected at a first junction, and a second branch of the two remaining switches connected at a second junction, said second branch being connected in parallel with said first branch, one of said stator windings being connected between said first junction and said second junction, two diametrically opposite switches in said H-bridge circuit being alternately conductive during each voltage pulse.
Claim 5
Dependent Claim
48 words
A circuit as defined in claim 3, including a third branch of two switches connected at a third junction, said third branch being connected in parallel with said second branch and said first branch; and a second stator winding connected between said second junction and said third junction.
Claim 6
Dependent Claim
21 words
A circuit as defined in claim 4, including a third stator winding connected between said first junction and said third junction.
Claim 7
Dependent Claim
23 words
A circuit as defined in claim 1, wherein said voltage pulses have always the same phase within one period of said line voltage.
Claim 8
Dependent Claim
29 words
A circuit as defined in claim 1, further including a choke means connected to said source of line voltage for suppressing harmonic waves from said source of line voltage.
References Cited (Backward Citations)
US3470436A
Cited
US3564372A
Cited
US3959709A
Cited
US4039915A
Cited
JPS5216158A
Cited
US4238719A
Cited
US4431958A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-09-06 | 1992-03-07 | 1992-09-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-09-06 | 1996-03-07 | 1996-09-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-09-06 | 2000-03-07 | 2000-09-06 | $7700.00 | Window Closed / Lapsed |