US4532461A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Rotor position sensor error detection
Assignee: Kollmorgen Technologies Corp
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Filing: 1983-11-01
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Granted: 1985-07-30
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Expires: 2003-11-01
Abstract
Abstract In a brushless DC motor of the type having a control circuit and a plurality of position sensors, an error detector responsive to the position sensors is used to generate an error signal useful in shutting off the motor. The output signals of the position sensors provide a numerical code representative of the rotation of the rotor relative to the windings. When the numerical code deviates from a predetermined sequence, the error detector generates an error signal and the control circuit shuts off the motor.
Inventors
- 👤 James C. Crook
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 00:46
CPC Classifications
H; H02; H02P; H02P6/00; H02P6/12
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
101 words
A brushless D.C. motor control system comprising: a brushless D.C. motor which includes a stator having a plurality of windings and a rotor; a plurality of position sensors disposed about said rotor to provide digital position signals indicative of the position of said rotor relative to said stator; a control circuit responsive to the digital position signals for commutating said windings; and a protection circuit responsive to said position sensors for detecting a logical error among the digital position signals and for providing said control circuit with an error signal to shut off said motor when such logical errors are detected.
Claim 2
Dependent Claim
101 words
A brushless D.C. motor control system comprising: a brushless D.C. motor which includes a stator having a plurality of windings and a rotor; a plurality of position sensors disposed about said rotor to provide digital position signals indicative of the position of said rotor relative to said stator; a control circuit responsive to the digital position signals for commutating said windings; and a protection circuit responsive to said position sensors for detecting a logical error among the digital position signals and for providing said control circuit with an error signal to shut off said motor when such logical errors are detected.
Claim 3
Dependent Claim
53 words
A control system according to claim 1 wherein said protection circuit includes sequential logic means for comparing the present state of the digital position signals to the previous state of the digital position signals and for providing the error signal when the present state of digital position signals deviates from a predetermined sequence.
Claim 4
Dependent Claim
20 words
A control system according to claim 1 wherein said protection circuit includes memory means responsive to the digital position signals.
Claim 5
Dependent Claim
17 words
A control system according to claim 3 which further includes switching means for resetting said memory means.
Claim 6
Dependent Claim
22 words
A control system according to claim 4 wherein said position sensors include a plurality of Hall sensors disposed equiangularly about said rotor.
Claim 7
Dependent Claim
17 words
A control system according to claim 5 wherein said memory means includes a programmable read only memory.
Claim 8
Dependent Claim
18 words
A control system according to claim 6 wherein said memory means includes a plurality of D-type flip flops.
Claim 9
Dependent Claim
22 words
A control system according to claim 7 wherein said programmable read only memory includes feedback means responsive to said D-type flip flops.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-07-29 | 1989-01-28 | 1989-07-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-07-29 | 1993-01-28 | 1993-07-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-07-29 | 1997-01-28 | 1997-07-30 | $7700.00 | Window Closed / Lapsed |