US4471282A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Step motor excitation system
Assignee: Fujifilm Business Innovation Corp
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Filing: 1982-04-30
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Granted: 1984-09-11
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Expires: 2002-04-30
Abstract
Abstract A step motor provided with a plurality of coils and driven in a one-two phase excitation mode is provided with a current setting device by which the current flowing in the coils is changed when switching from one to two phase excitation, to linearize the time dependence of the rotation angle of the motor.
Inventors
- 👤 Fujio Moriguchi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 12:26
CPC Classifications
H; H02; H02P; H02P8/00; H02P8/12
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
114 words
A step motor excitation system comprising; a drive circuit including current detecting means for detecting an exciting current flowing in each exciting coil of said step motor, wherein said exciting current in said each exciting coil has a uniform wavelength and each exciting current is separated by one-quarter period from the other, constant current control means for controlling said exciting current detected by said current detecting means so as to have a predetermined current value, and current setting means for setting said predetermined current values in a one-phase excitation and in a two-phase excitation of said step motor so as to be different from one another, respectively, in correspondence to one-phase and two-phase excitations.
Claim 2
Dependent Claim
114 words
A step motor excitation system comprising; a drive circuit including current detecting means for detecting an exciting current flowing in each exciting coil of said step motor, wherein said exciting current in said each exciting coil has a uniform wavelength and each exciting current is separated by one-quarter period from the other, constant current control means for controlling said exciting current detected by said current detecting means so as to have a predetermined current value, and current setting means for setting said predetermined current values in a one-phase excitation and in a two-phase excitation of said step motor so as to be different from one another, respectively, in correspondence to one-phase and two-phase excitations.
Claim 3
Dependent Claim
17 words
A system as claimed in claim 1, wherein said constant current control means comprises chopper transistor means.
Claim 4
Dependent Claim
19 words
A system as claimed in claim 2, wherein an on-off operation of said chopper is controlled by comparator means.
Claim 5
Dependent Claim
24 words
A system as claimed in claim 3, further including means for providing a periodically varying reference voltage as one input of said comparator means.
Claim 6
Dependent Claim
16 words
A system as claimed in claim 1, wherein said current setting means comprises voltage divider means.
Claim 7
Dependent Claim
29 words
A system as claimed in claim 4, wherein said current setting means comprises voltage divider means, an output of said voltage divider forming a second input of said comparator.
Claim 8
Independent Claim
33 words
A system as claimed in claims 5 or 6, said voltage divider means comprising a series resistor circuit and a switching transistor for controlling a voltage dividing operation of said voltage divider means.
Claim 9
Dependent Claim
28 words
A system as claimed in claim 7, including means for controlling said switching transistor and the flow of current to said coils comprising counter means and decoder means.
Claim 10
Dependent Claim
32 words
A system as claimed in claim 8, said switching transistor being enabled by said decoder means to effect a voltage division operation by said voltage divider means during a one-phase excitation interval.
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) | 1987-09-11 | 1988-03-12 | 1988-09-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-09-11 | 1992-03-12 | 1992-09-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-09-11 | 1996-03-12 | 1996-09-11 | $7700.00 | Window Closed / Lapsed |