Patent ID: 6441579
Filing Date: 2002-08-27
Classification: G05B,H02P,Y10S

Abstract:
In a device including a microprocessor and a programmable motor controller which conducts an open loop control of power from a power supply to a stepper motor, a method for open loop control of power from the power supply to the stepper motor, the method comprising steps of:sensing a voltage provided by the power supply through an input to the microprocessor; calculating, in the microprocessor, a scale factor dependent on sensitivity of current in the stepper motor to the voltage provided by the power supply; setting driving parameters in the programmable motor controller to drive the stepper motor as a function of the scale factor, wherein the driving parameters comprise sets of pulse width modulation values, and said step of setting preserves PWM values at a leading edge of a current waveform at a maximum value to minimize motor current rise time.