US3885210A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Drive circuits for stepping motors
Assignee: Wickman Machine Tool Sales Ltd
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Filing: 1973-11-21
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Granted: 1975-05-20
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Expires: 1993-11-21
Abstract
Abstract In a stepping motor having a plurality of windings which are energised in sequence to effect the required stepping movement of the motor, the drive circuit for the motor varies the current flowing in each winding in incremental steps between zero and a maximum value. Ideally the incremental steps are unequal but are arranged to produce equal incremental steps of the motor.
Inventors
- 👤 Alan Burnett
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 21:12
CPC Classifications
H; H02; H02P; H02P8/00; H02P8/14; H02P8/16; H02P8/165
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
97 words
A drive circuit and a stepping motor of the kind incorporating a plurality of windings which are energized in sequence to effect the required stepping movement of the motor, said drive circuit comprising means for selectively varying the current flowing in each winding in unequal incremental steps between zero and a maximum value, and means permitting selection of the magniTude of each incremental step independently of the other incremental steps, so as to enable the incremental steps to be set independently to match the non-linear characteristic of the motor to obtain equal incremental steps of the motor.
Claim 2
Dependent Claim
97 words
A drive circuit and a stepping motor of the kind incorporating a plurality of windings which are energized in sequence to effect the required stepping movement of the motor, said drive circuit comprising means for selectively varying the current flowing in each winding in unequal incremental steps between zero and a maximum value, and means permitting selection of the magniTude of each incremental step independently of the other incremental steps, so as to enable the incremental steps to be set independently to match the non-linear characteristic of the motor to obtain equal incremental steps of the motor.
Claim 3
Dependent Claim
56 words
A drive circuit and a stepping motor as claimed in claim 1 comprising a first voltage supply for energizing the windings under the control of the drive circuit, a second and higher voltage supply, and switch means operable when the required stepping rate exceeds a predetermined value for coupling the windings to the second voltage supply.
Claim 4
Dependent Claim
40 words
A drive circuit and a stepping motor as claimed in claim 1 comprising means for switching on or off a transistor in series with the winding to establish in the winding a mean current flow equal to the required current.
Claim 5
Dependent Claim
63 words
A drive circuit and a stepping motor as claimed in claim 1 comprising an operational amplifier, means to feed to said amplifier a signal representing the required current in a winding, and means to direct a feedback signal representing the actual current flow in the winding to said operational amplifier, the output from said amplifier then controlling the current flow in the winding.
References Cited (Backward Citations)
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US3662245A
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US3757193A
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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) | 1978-05-19 | 1978-11-18 | 1979-05-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-05-19 | 1982-11-18 | 1983-05-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-05-19 | 1986-11-18 | 1987-05-20 | $7700.00 | Window Closed / Lapsed |