US4510429A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Stepper motor damping circuit and a method therefor
Assignee: Tulin Corp
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Filing: 1983-08-19
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Granted: 1985-04-09
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Expires: 2003-08-19
Abstract
Abstract A control circuit for a stepper motor is disclosed. The stepper motor is driven by a chopper drive circuit. The frequency and the duty cycle of the stator or motor winding to which the chopper drive circuit has supplied the current is measured. The frequency and duty cycle measured are related to the back EMF induced in the driven stator. The back EMF is filtered and is used in a negative feedback manner and is supplied to the quadrature phase of the stepper motor to provide a damped step response.
Inventors
- 👤 John S. Squire
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 02:01
CPC Classifications
H; H02; H02P; H02P8/00; H02P8/12; H02P8/32
Claims Analysis
Total Claims: 25
Claim 1
Independent Claim
73 words
A method of damping a stepper motor having a rotor and a first and a second stator, said method comprising the steps of: applying a first voltage to said first stator; detecting the total voltage from said first stator; filtering the back voltage generated by said motor from said total voltage and applying a drive current to said second stator to damp said motor, said drive current being proportional to said back voltage.
Claim 2
Independent Claim
73 words
A method of damping a stepper motor having a rotor and a first and a second stator, said method comprising the steps of: applying a first voltage to said first stator; detecting the total voltage from said first stator; filtering the back voltage generated by said motor from said total voltage and applying a drive current to said second stator to damp said motor, said drive current being proportional to said back voltage.
Claim 3
Dependent Claim
28 words
The method of claim 1 further comprising the step of: applying said drive current to said second stator when said motor is being moved in the final step.
Claim 4
Dependent Claim
35 words
The method of claim 2 wherein said first voltage has a frequency and a duty cycle, said frequency and duty cycle of said first voltage being proportional to the back voltage generated from said motor.
Claim 5
Dependent Claim
26 words
The method of claim 3 further comprising the step of amplifying said filtered back voltage and generating said drive current proportional to said amplified back voltage.
Claim 6
Independent Claim
115 words
A method of operating a stepper motor, having a rotor and a first and a second stator, in moving said rotor from a first position to a second position through a plurality of steps, comprising the steps of: determining when said rotor is one step away from said second position; applying a first voltage to said first stator to move said rotor to said second position; detecting the back voltage generated by said motor from said first stator; and applying a drive current to said second stator in quadrature phase to said first voltage being applied to said first stator, said drive current being proportional to said back voltage being applied during said one step.
Claim 7
Independent Claim
115 words
A method of operating a stepper motor, having a rotor and a first and a second stator, in moving said rotor from a first position to a second position through a plurality of steps, comprising the steps of: determining when said rotor is one step away from said second position; applying a first voltage to said first stator to move said rotor to said second position; detecting the back voltage generated by said motor from said first stator; and applying a drive current to said second stator in quadrature phase to said first voltage being applied to said first stator, said drive current being proportional to said back voltage being applied during said one step.
Claim 8
Dependent Claim
25 words
The method of claim 5 further comprising the step of amplifying said back current and generating said drive energy proportional to said amplified back current.
Claim 9
Independent Claim
92 words
A method for damping the rotational motion of a stepper motor of the type having a first and a second motor winding positioned in quadrature phase, said first winding being energized and switched and said second winding being energized and not switched when said motor is being advanced in the final step, said method comprising the steps of: sensing the voltage from said first winding; isolating the back voltage from said first winding from the sensed voltage; amplifying said isolated back voltage; and applying said amplified back voltage to said second winding.
Claim 10
Independent Claim
92 words
A method for damping the rotational motion of a stepper motor of the type having a first and a second motor winding positioned in quadrature phase, said first winding being energized and switched and said second winding being energized and not switched when said motor is being advanced in the final step, said method comprising the steps of: sensing the voltage from said first winding; isolating the back voltage from said first winding from the sensed voltage; amplifying said isolated back voltage; and applying said amplified back voltage to said second winding.
Claim 11
Independent Claim
96 words
An apparatus for use with a stepper motor of the type having a rotor and a first and a second stator, said apparatus comprising: means for applying a drive voltage to said first stator; means for sensing the total voltage from said first stator; means for filtering the back voltage generated by said motor in said first stator from said total voltage; and means for applying a drive current to said second stator in quadrature phase to said drive voltage being applied to said first stator, said drive current being proportional to said filtered back voltage.
Claim 12
Independent Claim
96 words
An apparatus for use with a stepper motor of the type having a rotor and a first and a second stator, said apparatus comprising: means for applying a drive voltage to said first stator; means for sensing the total voltage from said first stator; means for filtering the back voltage generated by said motor in said first stator from said total voltage; and means for applying a drive current to said second stator in quadrature phase to said drive voltage being applied to said first stator, said drive current being proportional to said filtered back voltage.
Claim 13
Dependent Claim
19 words
The apparatus of claim 8 wherein said means for applying a drive voltage is a bipolar chopping current driver.
Claim 14
Dependent Claim
22 words
The apparatus of claim 8 wherein said sensing means is a resistor positioned to detect the total voltage from said first stator.
Claim 15
Dependent Claim
30 words
The apparatus of claim 8 wherein said filtering means is a filter with a high frequency cut-off of approximately 2 KHz, and a low frequency cut-off of approximately 60 Hz.
Claim 16
Dependent Claim
20 words
The apparatus of claim 8 wherein said means for applying a drive current is also a bipolar chopping current driver.
Claim 17
Dependent Claim
13 words
The apparatus of claim 8 further comprising: means for amplifying said back voltage.
Claim 18
Independent Claim
118 words
An apparatus for use with a stepper motor of the type having a rotor and a first and a second stator, for moving said rotor from a first position to a second position through a plurality of steps, said apparatus comprising: means for determining when said rotor is one step from said second position; means for applying a drive voltage to said first stator; means for sensing the back voltage generated by said motor from said first stator; and means for applying a drive current to said second stator in quadrature phase to said drive voltage being applied to said first stator, said drive current having a constant bias part and a part proportional to said back voltage.
Claim 19
Independent Claim
118 words
An apparatus for use with a stepper motor of the type having a rotor and a first and a second stator, for moving said rotor from a first position to a second position through a plurality of steps, said apparatus comprising: means for determining when said rotor is one step from said second position; means for applying a drive voltage to said first stator; means for sensing the back voltage generated by said motor from said first stator; and means for applying a drive current to said second stator in quadrature phase to said drive voltage being applied to said first stator, said drive current having a constant bias part and a part proportional to said back voltage.
Claim 20
Dependent Claim
19 words
The apparatus of claim 14 wherein said means for applying a drive voltage is a bipolar chopping current driver.
Claim 21
Dependent Claim
39 words
The apparatus of claim 14 wherein said sensing means is a resistor positioned to detect the drive voltage whose duty cycle is proportional to said back voltage and a filter to filter the back voltage from said duty cycle.
Claim 22
Dependent Claim
20 words
The apparatus of claim 14 wherein said means for applying a drive current is also a bipolar chopping current driver.
Claim 23
Dependent Claim
14 words
The apparatus of claim 14 further comprising: means for amplifying the back voltage sensed.
Claim 24
Independent Claim
97 words
An apparatus for damping the rotational motion of a stepper motor of the type having a first and a second motor winding mounted in quadrature phase, said first winding being energized and switched and said second winding being energized and not switched, when said motor is being advanced in the final step, said apparatus comprising: means for sensing the voltage from said first winding; means for isolating the back voltage from said first winding from the sensed voltage means for amplifying said isolated back voltage; and means for applying said amplified back voltage to said second winding.
Claim 25
Independent Claim
97 words
An apparatus for damping the rotational motion of a stepper motor of the type having a first and a second motor winding mounted in quadrature phase, said first winding being energized and switched and said second winding being energized and not switched, when said motor is being advanced in the final step, said apparatus comprising: means for sensing the voltage from said first winding; means for isolating the back voltage from said first winding from the sensed voltage means for amplifying said isolated back voltage; and means for applying said amplified back voltage to said second winding.
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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) | 1988-04-08 | 1988-10-08 | 1989-04-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-04-08 | 1992-10-08 | 1993-04-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-04-08 | 1996-10-08 | 1997-04-09 | $7700.00 | Window Closed / Lapsed |