US4590412A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of energizing a stepping motor
Assignee: Omega SA
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Filing: 1984-09-11
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Granted: 1986-05-20
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Expires: 2004-09-11
Abstract
Abstract A method of controlling a stepping motor comprises supplying the motor with a predetermined quantity of energy E io from whence there will result an automatic adaptation of the width of the motor drive pulse to the voltage U o at the motor terminals and the resistance R i of the energy source. At the moment when the internal energy E i (t) supplied to the motor, as defined by the integral over a time period of the product of U o -RI and the current I t circulating in the motor winding, becomes equal to E io the drive pulse is cut off (R is the resistance of the motor winding). The circuit for practicing the method according to the invention includes means for measuring the voltage U o and the energizing current I(t), means for obtaining the difference U o -RI, a multiplier for forming the product (U o -RI)I(t) and an integrator the output of which provides a voltage proportional to the internal energy E i (t).
Inventors
- 👤 Mohamed Mokdad
- 👤 Mai T. Xuan
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 14:40
CPC Classifications
G; G04; G04C; G04C3/00; G04C3/14; G04C3/143
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
248 words
A method of controlling the application of motor drive pulses having varying widths from an energy source having a changing internal resistance R i to a stepping motor, said method comprising the steps of: determining an energy threshold E io to be supplied to the motor by a pulse for which stepping is assured in all cases of normally occurring loads; continually measuring the instantaneous voltage U o across the motor winding terminals and the instantaneous current I(t) circulating in said winding during a pulse supplied by said energy source, the values of said instantaneous voltage U o and instantaneous current I(t) being dependent on the internal resistance R i of said energy source; continually calculating the difference U o -RI where R represents the winding resistance during said pulse; continually forming the product (U o -RI) I(t) during said pulse; continually integrating said product over a time period t during said pulse whereby the value of the integral represents the energy E i (t) supplied to the motor; continually comparing the measured value E i (t) during said pulse to the predetermined threshold value E io ; and, cutting off the energy supply when E i (t)=E io to form the end of said pulse whereby the width of a motor drive pulse varies as the voltage U o and the resistance R i of the energy source vary to provide a predetermined quantity of energy equal to said energy threshold E io to the motor winding.
Claim 2
Independent Claim
248 words
A method of controlling the application of motor drive pulses having varying widths from an energy source having a changing internal resistance R i to a stepping motor, said method comprising the steps of: determining an energy threshold E io to be supplied to the motor by a pulse for which stepping is assured in all cases of normally occurring loads; continually measuring the instantaneous voltage U o across the motor winding terminals and the instantaneous current I(t) circulating in said winding during a pulse supplied by said energy source, the values of said instantaneous voltage U o and instantaneous current I(t) being dependent on the internal resistance R i of said energy source; continually calculating the difference U o -RI where R represents the winding resistance during said pulse; continually forming the product (U o -RI) I(t) during said pulse; continually integrating said product over a time period t during said pulse whereby the value of the integral represents the energy E i (t) supplied to the motor; continually comparing the measured value E i (t) during said pulse to the predetermined threshold value E io ; and, cutting off the energy supply when E i (t)=E io to form the end of said pulse whereby the width of a motor drive pulse varies as the voltage U o and the resistance R i of the energy source vary to provide a predetermined quantity of energy equal to said energy threshold E io to the motor winding.
Claim 3
Dependent Claim
74 words
A method as set forth in claim 1 wherein the product (U o -RI) I(t) is integrated between two time limits, a first for which t=0 corresponding to the instant of application of the motor drive pulse and a second for which t=T i max , T i max representing the maximum motor drive pulse width in a situation where the energy supplied to the motor is not sufficient to reach the predetermined energy.
Claim 4
Dependent Claim
301 words
A control circuit for controlling the application of motor drive pulses having varying widths from an energy source having a changing internal resistance R i to a stepping motor, said control circuit comprising: first means for generating a signal representing an energy threshold E io to be supplied to the motor by a pulse for which stepping is assured in all cases of normally occurring loads; second means for continuously measuring the instantaneous voltage U o across the motor winding terminals and the instantaneous current I(t) circulating in said winding during a pulse supplied by said energy source, the values of said instantaneous voltage U o and current I(t) being dependent on the internal resistance R i of said energy source; third means responsive to said second means for continuously calculating the difference U o -RI where R represents the winding resistance during said pulse; multiplier means responsive to said second means and said third means for continuously forming the product (U o -RI) I(t) during said pulse; integrating means responsive to said multiplier means for continuously integrating said product over a time period t during said pulse whereby the value of the integral represents the energy E i (t) supplied to the motor; and, comparing means responsive to said first means and said integrating means for continuously comparing the measured value E i (t) during said pulse to the predetermined threshold value E io ; said comparing means including further means for cutting off the energy supply when E i (t)=E io to form the end of said pulse, whereby the width of a motor drive pulse varies as the voltage U o and the resistance R i of the energy source vary to provide a predetermined quantity of energy equal to said energy threshold E io to said motor.
Claim 5
Dependent Claim
301 words
A control circuit for controlling the application of motor drive pulses having varying widths from an energy source having a changing internal resistance R i to a stepping motor, said control circuit comprising: first means for generating a signal representing an energy threshold E io to be supplied to the motor by a pulse for which stepping is assured in all cases of normally occurring loads; second means for continuously measuring the instantaneous voltage U o across the motor winding terminals and the instantaneous current I(t) circulating in said winding during a pulse supplied by said energy source, the values of said instantaneous voltage U o and current I(t) being dependent on the internal resistance R i of said energy source; third means responsive to said second means for continuously calculating the difference U o -RI where R represents the winding resistance during said pulse; multiplier means responsive to said second means and said third means for continuously forming the product (U o -RI) I(t) during said pulse; integrating means responsive to said multiplier means for continuously integrating said product over a time period t during said pulse whereby the value of the integral represents the energy E i (t) supplied to the motor; and, comparing means responsive to said first means and said integrating means for continuously comparing the measured value E i (t) during said pulse to the predetermined threshold value E io ; said comparing means including further means for cutting off the energy supply when E i (t)=E io to form the end of said pulse, whereby the width of a motor drive pulse varies as the voltage U o and the resistance R i of the energy source vary to provide a predetermined quantity of energy equal to said energy threshold E io to said motor.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1989-05-19 | 1989-11-18 | 1990-05-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-05-19 | 1993-11-18 | 1994-05-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-05-19 | 1997-11-18 | 1998-05-20 | $7700.00 | Window Closed / Lapsed |