US4438379A
Expired / Lapsed
US
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Method of damping a stepping motor
Assignee: Amtech Patent Licensing Corp
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Filing: 1981-06-15
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Granted: 1984-03-20
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Expires: 2001-06-15
Abstract
Abstract For a stepping motor having a rotatable stator magnetic field for driving the rotor, there is disclosed a method of damping the oscillations of the rotor which occurs when the rotatable stator magnetic field is stopped upon arriving at a desired rotational position by measuring quantities related to the instantaneous velocity of the rotor due to the oscillations of the rotor about the desired rotational position, rotationally displacing the stator magnetic field from the desired rotational position in a direction opposite to the direction of the oscillation, and thereafter returning the stator magnetic field to the desired stopping position.
Inventors
- 👤 David Chiang
- 👤 Mosi Chu
- 👤 Solomon Manber
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 06:27
CPC Classifications
H; H02; H02P; H02P8/00; H02P8/32
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
125 words
In a stepping motor having a rotatable stator magnetic field for driving the rotor, the method of damping the oscillations of the rotor which occur when the rotatable stator magnetic field is stopped upon arriving at a desired rotational position comprising a first step of measuring quantities related to the instantaneous velocity of the rotor due to the oscillations of the rotor about the desired rotational position, a second step of modifying the stator magnetic field by at least a rotational displacement from the desired rotational position in a direction opposite to the direction of the oscillation by an amount which is a continuous function of the instantaneous velocity, and a third step of thereafter returning the stator magnetic field to the desired stopping position.
Claim 2
Dependent Claim
125 words
In a stepping motor having a rotatable stator magnetic field for driving the rotor, the method of damping the oscillations of the rotor which occur when the rotatable stator magnetic field is stopped upon arriving at a desired rotational position comprising a first step of measuring quantities related to the instantaneous velocity of the rotor due to the oscillations of the rotor about the desired rotational position, a second step of modifying the stator magnetic field by at least a rotational displacement from the desired rotational position in a direction opposite to the direction of the oscillation by an amount which is a continuous function of the instantaneous velocity, and a third step of thereafter returning the stator magnetic field to the desired stopping position.
Claim 3
Dependent Claim
16 words
The method of claim 1 wherein said measured quantities are the rotational position of the rotor.
Claim 4
Dependent Claim
18 words
The method of claim 2 wherein the amount of displacement is related to the magnitude of measured quantities.
Claim 5
Dependent Claim
42 words
The method of claim 3 wherein said third step comprises performing a set of pairs of said first and second steps such that as the measured velocity decreases the rotational displacement of the stator magnetic field converge to the desired rotational position.
Claim 6
Dependent Claim
28 words
The method of claim 2 wherein said first step comprises measuring the instantaneous positions of the rotor and periodically occurring instants of time and subtracting two successive measurements.
Claim 7
Dependent Claim
28 words
The method of claim 2 wherein said first step comprises measuring the two peak values of the rotational position of the rotor during one cycle of the oscillation.
Claim 8
Dependent Claim
21 words
The method of claim 6 wherein the amount of displacement is related to the amplitude of one of the peak values.
Claim 9
Dependent Claim
33 words
The method of claim 7 wherein said third step is performed at a time equal to one quarter of the period of oscillation of the rotor after the performance of the second step.
Claim 10
Independent Claim
40 words
The method of claims 1, 2, 5, 6, or 7 wherein for said second step the amount of the displacement is fixed and the amplitude of the rotatable stator magnetic field is related to the magnitude of the measured quantities.
Claim 11
Dependent Claim
47 words
The method of claim 2 or 5, wherein said third step comprises performing a set of pairs said first and second steps such that as the measured velocity decreases the amplitude of the rotatable stator magnetic field converges to the magnitude normal for the stopped rotational position.
Claim 12
Dependent Claim
45 words
The method of claim 9 wherein said third step comprises perform a set of pairs said first and second steps such that as the measured velocity decreases the amplitude of the rotatable stator magnetic field converges to the magnitude normal for the stopped rotational position.
References Cited (Backward Citations)
US4107594A
Cited
US4349770A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-03-20 | 1987-09-19 | 1988-03-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-03-20 | 1991-09-19 | 1992-03-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-03-20 | 1995-09-19 | 1996-03-20 | $7700.00 | Window Closed / Lapsed |