US4455520A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and means for stable operation of a synchronous motor
Assignee: Parker Intangibles LLC
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Filing: 1981-05-29
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Granted: 1984-06-19
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Expires: 2001-05-29
Abstract
Abstract Stability in operating a synchronous stepping motor in mid-frequency is achieved by monitoring instantaneous power to the motor and adjusting the phase of the motor drive waveform as needed to maintain uniform speed. In an embodiment in which a pulse width modulator responds to a reference signal waveform, the phase of the reference signal waveform is varied to adjust the instantaneous power delivered to the motor.
Inventors
- 👤 Kenneth C. Ward
- 👤 Ross Welburn
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 05:22
CPC Classifications
H; H02; H02P; H02P8/00; H02P8/14; H02P25/00; H02P25/02; H02P25/022; H02P25/024; H02P8/32
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
43 words
The method of driving a synchronous motor and avoiding parametric resonance comprising the steps of applying a modulated current to the windings of said motor, monitoring power to said motor, and varying the phase of said modulated current to offset changes in power.
Claim 2
Independent Claim
43 words
The method of driving a synchronous motor and avoiding parametric resonance comprising the steps of applying a modulated current to the windings of said motor, monitoring power to said motor, and varying the phase of said modulated current to offset changes in power.
Claim 3
Independent Claim
47 words
The method of driving a synchronous motor and controlling operation stability thereof comprising the steps of monitoring power to said motor, increasing current phase and thereby increasing motor speed when the monitored power decreases current, and decreasing phase and thereby decreasing motor speed when monitored power increases.
Claim 4
Independent Claim
47 words
The method of driving a synchronous motor and controlling operation stability thereof comprising the steps of monitoring power to said motor, increasing current phase and thereby increasing motor speed when the monitored power decreases current, and decreasing phase and thereby decreasing motor speed when monitored power increases.
Claim 5
Dependent Claim
35 words
The method of driving a synchronous motor as defined by claim 2 wherein said steps of decreasing and increasing current phase includes varying the phase of a reference signal applied to a pulse width modulator.
Claim 6
Dependent Claim
54 words
Apparatus for stably driving a synchronous motor comprising means for applying current to a winding of said motor, means for detecting power to said motor, means for increasing the phase of current to said winding when detected power decreases, and means for decreasing the phase of current to said winding when detected power increases.
Claim 7
Dependent Claim
54 words
Apparatus for stably driving a synchronous motor comprising means for applying current to a winding of said motor, means for detecting power to said motor, means for increasing the phase of current to said winding when detected power decreases, and means for decreasing the phase of current to said winding when detected power increases.
Claim 8
Dependent Claim
30 words
Apparatus as defined by claim 4 wherein said means for increasing phase and for decreasing phase comprises means for adjusting phase of a control signal for a pulse width modulator.
Claim 9
Dependent Claim
64 words
Drive circuitry for a synchronous motor comprising means for generating a reference signal waveform, a pulse width modulator for receiving said reference signal waveform and generating a motor winding current, means for applying said winding current to said motor, monitoring means for monitoring power applied to said motor, and means responsive to said monitoring means for varying the phase of said reference signal waveform.
Claim 10
Dependent Claim
64 words
Drive circuitry for a synchronous motor comprising means for generating a reference signal waveform, a pulse width modulator for receiving said reference signal waveform and generating a motor winding current, means for applying said winding current to said motor, monitoring means for monitoring power applied to said motor, and means responsive to said monitoring means for varying the phase of said reference signal waveform.
Claim 11
Dependent Claim
30 words
Drive circuitry as defined by claim 6 wherein said means responsive to said monitoring means comprises phase shift circuitry for receiving said reference signal waveform and shifting the phase thereof.
Claim 12
Dependent Claim
38 words
Drive circuitry as defined by claim 6 wherein said means responsive to said monitoring means comprises means for altering the address supplied to a read only memory in which the magnitude of a reference signal waveform is stored.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-06-19 | 1987-12-19 | 1988-06-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-06-19 | 1991-12-19 | 1992-06-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-06-19 | 1995-12-19 | 1996-06-19 | $7700.00 | Window Closed / Lapsed |