Method and apparatus for determining stepping motor parameters from induced voltages
AssigneeInternational Business Machines Corporation
InventorsHartmut Ulland, Volker Zimmermann, Rainer Zuehlke
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Abstract
An improved method and apparatus for determining the speed and position values of a stepping motor for controlling or regulating the same. These values are derived from induced voltages within the bifilar windings of the stepping motor combined with voltages across and currents through the same bifilar windings. The speed values are derived from the amplitude of the induced voltages and the position values are derived from the zero transitions of the induced voltages. A desirable advance of the motor is distinguished from an undesirable oscillation of the motor by determining whether the induced voltages in the bifilar windings become zero simultaneously.
Claims8
In combination with an electrical stepping motor having at least two bifilar winding pairs, means for determining speed and position values of said stepping motor comprising:
- amplifying means for receiving induced voltages within the said bifilar windings of the said stepping motor in addition to applied voltages across and currents through the said bifilar windings;
- rectifier means responsive to said induced voltages for providing an output signal proportional to the instantaneous speed values of the said stepping motor;
- and
- detector means responsive to said induced voltages for providing an output signal indicative of the position of the said stepping motor.
In combination with an electrical stepping motor having at least two bifilar winding pairs, means for determining speed and position values of said stepping motor comprising:
- two differential amplifiers for receiving induced voltages within the said bifilar windings of the said stepping motor in addition to applied voltages across and currents through the said bifilar windings;
- an operational amplifier for combining the outputs of the said two differential amplifiers and for providing an output voltage which corresponds to the said induced voltages of said stepping motor;
- a peak-value rectifier connected to the output of said operational amplifier and responsive to said induced voltages for providing an output signal proportional to the instantaneous speed value of the said stepping motor, and
- a zero detector for determining the position of said stepping motor by comparing the output voltage of said operational amplifier with a reference potential.
In combination with an electrical stepping motor having at least two bifilar winding pairs, means for determining speed and position values of said stepping motor comprising:
- two differential amplifiers joined to said bifilar winding pairs for receiving current and voltage values from said stepping motor, with one of said two differential amplifiers measuring the voltages across the said bifilar winding pairs, and the other one of said two differential amplifiers measuring the currents passing through the said bifilar winding pairs;
- an operational amplifier connected to the outputs of said two differential amplifiers for combining induced voltages on the said bifilar windings of the said stepping motor with applied voltages across and currents through the said bifilar windings and for providing an output voltage which corresponds to the said induced voltages of said stepping motor;
- peak-value rectifier connected to the output of said operational amplifier and responsive to said induced voltages for providing an output signal proportional to the instantaneous speed values of the said stepping motor, and
- a zero-detector connected to the output of said operational amplifier and responsive to said induced voltages for providing an output signal indicative of the position of the said stepping motor.
Dependencies are inferred from the claim text.