Stepper motor control
First Claim
1. An improved stepper motor drive system comprising, in combination:
- a permanent magnet stepper motor,a microprocessor controlled switching circuit means for supplying drive pulses to said motor,a power supply for providing excitation current to said switching circuit means,control means operative through said microprocessor controlled switching circuit means comprising means for inputting a preselected count to counter means corresponding to a desired number of drive pulses to said motor, means for decrementing said counter means by one count after each pulse is applied to said stepping motor until a zero count is reached, and means for terminating said excitation current after a predetermined time delay subsequent to reaching the zero count.
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Accused Products
Abstract
An improvement in the operation of a system where the driving means is a stepper motor comprises provision of a special software routine implemented by a microprocessor controlling the delivery of a counted series of pulses to drive the stepper motor. The improved routine removes excitation from the stepper motor when not receiving a series of stepping pulses thus eliminating the heat dissipation of such a motor when not in motion. Loss of position is avoided by utilizing the inherent detenting action of the stepper motor'"'"'s permanent magnet field. Provision is also made for proper damping to prevent error due to overshoot. Where several stepper motors are used in a system the reduction of heat dissipation permits a significant simplification of the system cooling requirements. A single power supply may be shared among the motors thus further simplifying the system.
36 Citations
6 Claims
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1. An improved stepper motor drive system comprising, in combination:
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a permanent magnet stepper motor, a microprocessor controlled switching circuit means for supplying drive pulses to said motor, a power supply for providing excitation current to said switching circuit means, control means operative through said microprocessor controlled switching circuit means comprising means for inputting a preselected count to counter means corresponding to a desired number of drive pulses to said motor, means for decrementing said counter means by one count after each pulse is applied to said stepping motor until a zero count is reached, and means for terminating said excitation current after a predetermined time delay subsequent to reaching the zero count. - View Dependent Claims (2, 3, 4, 5, 6)
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Specification