US5378975A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Position measurement of a stepping motor
Assignee: Xerox Corp
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Filing: 1992-12-18
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Granted: 1995-01-03
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Expires: 2012-12-18
Abstract
Abstract A method for measuring the position of a stepping motor by generating a signal representative of the back electromotive force induced by the rotor in the coils of the motor, and estimating the actual position of the rotor from the signal representative of the back electromotive force induced by the rotor.
Inventors
- 👤 Stuart A. Schweid
- 👤 Robert M. Lofthus
- 👤 John E. McInroy
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 18:43
CPC Classifications
H; H02; H02P; H02P6/00; H02P6/14; H02P6/16; H02P6/18; H02P6/182; H02P8/00; H02P8/14
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
117 words
Apparatus for position measurement of a stepping motor having a rotor and a plurality of electromagnetic field windings adapted to be separately energized to control rotation of said rotor comprising: means for generating signals representative of a back electromotive force induced by said rotor in the field windings, the means for generating including means for indirect measurement of a field winding voltage through low-pass filtering of switching control logic of a full bridge amplifier and means for removal of a voltage contribution of the resistance and inductance of said field windings from the field winding voltage measurement, and means for estimating said roto position using the signals representative of the back electromotive force of said field windings.
Claim 2
Dependent Claim
117 words
Apparatus for position measurement of a stepping motor having a rotor and a plurality of electromagnetic field windings adapted to be separately energized to control rotation of said rotor comprising: means for generating signals representative of a back electromotive force induced by said rotor in the field windings, the means for generating including means for indirect measurement of a field winding voltage through low-pass filtering of switching control logic of a full bridge amplifier and means for removal of a voltage contribution of the resistance and inductance of said field windings from the field winding voltage measurement, and means for estimating said roto position using the signals representative of the back electromotive force of said field windings.
Claim 3
Dependent Claim
24 words
The apparatus for position measurement of claim 1 including means for estimating and correcting steady state phase error introduced by said low pass filtering.
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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) | 1998-01-02 | 1998-07-04 | 1999-01-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2002-01-02 | 2002-07-04 | 2003-01-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2006-01-02 | 2006-07-04 | 2007-01-03 | $7700.00 | Window Closed / Lapsed |