US3748566A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Stepping motor with compensated angular error
Assignee: Licentia Patent Verwaltungs GmbH
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Filing: 1971-02-25
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Granted: 1973-07-24
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Expires: 1991-02-25
Abstract
Abstract Compensation for the angular error of an electric stepping motor is provided by generating an electrical error signal whenever the rotor of the stepping motor deviates from a selected stepping position and then utilizing this error signal to correct or adjust the individual winding currents being supplied to the motor to cause the rotor to correctly position itself at the selected stepping position. The error signal is preferably derived, e.g., optically, from a pair of control tracks which are scanned and the signals combined to form a difference signal. The difference signal is in turn applied to switching amplifiers, which are digitally controlled between their on and off positions to selectively provide the winding currents for the motor to cause the rotor thereof to move to a selected stepping position, so as to correct the output current of the switching amplifier to compensate for the angular error.
Inventors
- 👤 P Brembs
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 13:05
CPC Classifications
H; H02; H02K; H02K37/00; H02P; H02P8/00; H02P8/34
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
94 words
In combination with an electrical stepping motor, means for compensating and correcting the angular error of said motor after it has been stepped to a selected stepping position comprising: means for providing an electrical analog signal whenever the angular position of the rotor of said stepping motor deviates from the desired absolute angular position at the selected stepping position and, means responsive to said electrical signal for adjusting the analog valve of the current then being supplied to the individual motor windings to cause said rotor to move to said desired absolute angular position.
Claim 2
Dependent Claim
94 words
In combination with an electrical stepping motor, means for compensating and correcting the angular error of said motor after it has been stepped to a selected stepping position comprising: means for providing an electrical analog signal whenever the angular position of the rotor of said stepping motor deviates from the desired absolute angular position at the selected stepping position and, means responsive to said electrical signal for adjusting the analog valve of the current then being supplied to the individual motor windings to cause said rotor to move to said desired absolute angular position.
Claim 3
Dependent Claim
75 words
The apparatus defined in claim 1 wherein said means for providing an electrical analog signal comprises: a disc mounted on said rotor and having at least one control track thereon whose information is related to the desired absolute angular positions of said motor; at least one scanning device responsive to the signal from said control track; and circuit means responsive to the output of said scanning device for providing an electrical analog signal related thereto.
Claim 4
Dependent Claim
66 words
The apparatus as defined in claim 2 wherein two of said scanning means are provided adjacent said disc and responsive to the control track for providing signals 180* out of phase; and wherein said circuit means responsive to the output of said scanning means includes a difference circuit for providing an output signal proportional to the difference between the output signals of said two scanning means.
Claim 5
Dependent Claim
36 words
The apparatus as defined in claim 3 wherein said disc contains a pair of control tracks whose signals are 180* out of phase, and each of said scanning means is associated with one of said tracks.
Claim 6
Dependent Claim
92 words
The apparatus as defined in claim 3 wherein said control tracks include alternate light transmissive and opaque areas; wherein each of said scanning devices is a photo-sensitive element which is positioned relative to its associated control track so that it is adjacent a transition point from a light transmissive to an opaque area thereof when said rotor is properly positioned at a desired absolute angular position at a selected stepping position, and wherein said difference circuit includes a bridge circuit with each of said photosensitive elements being in a separate arm thereof.
Claim 7
Dependent Claim
107 words
The apparatus as defined in claim 5 wherein: the output of said bridge circuit is fed to the input of a difference amplifier; each of said motor windings is connected to a separate switching amplifier which when selectively turned on supplies current to the associated motor windings; digital control means are provided for selectively switching said switching amplifiers between their on and off states in accordance with a desired stepping position; and, the output of said difference amplifier is connected to an input of selected ones of said switching amplifiers so as to impose a correction current corresponding to said electrical analog signal on the output thereof.
Claim 8
Dependent Claim
71 words
The apparatus as defined in claim 6 wherein said stepping motor has four windings arranged in two pairs of windings, wherein said digital control means controls said switching amplifiers so that one winding of each pair of windings is provided with current for each desired stepping position; and wherein the output signal of said difference amplifier is connected to only the switching amplifiers associated with one of said pair of windings.
Claim 9
Independent Claim
82 words
A method of compensating for the angular error of an electrical stepping motor after it has been stepped to a selected stepping position comprising: providing an electrical analog error signal whenever the angular position of the rotor deviates from the desired absolute angular position at a selected stepping position; and utilizing said electrical signal to adjust the analog value of the winding current then being supplied to said motor to cause the rotor to be moved to the desired absolute angular position.
Claim 10
Independent Claim
82 words
A method of compensating for the angular error of an electrical stepping motor after it has been stepped to a selected stepping position comprising: providing an electrical analog error signal whenever the angular position of the rotor deviates from the desired absolute angular position at a selected stepping position; and utilizing said electrical signal to adjust the analog value of the winding current then being supplied to said motor to cause the rotor to be moved to the desired absolute angular position.
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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) | 1976-07-23 | 1977-01-22 | 1977-07-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-07-23 | 1981-01-22 | 1981-07-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-07-23 | 1985-01-22 | 1985-07-24 | $7700.00 | Window Closed / Lapsed |