Patent ID: 6946814
Filing Date: 2005-09-20
Classification: H02P

Abstract:
1. A stepping motor driver which supplies sinusoidally varying exciting currents to a stepping motor each time an external command pulse is applied, comprising: (a) an excitation angle generating means which generates an excitation angle from the external command pulse; (b) a current control means which controls the exciting currents according to the excitation angle and a current command; (c) a current detection means which detects phase currents of the stepping motor; (d) an angle detection means which detects a rotor rotation angle of the stepping motor; (e) a torque component current calculating means which calculates a torque component current from the phase currents and the rotor rotation angle; (f) an absolute converting means which obtains the absolute value of the torque component current; and (g) a current command output means which outputs the current command depending on the absolute value of the torque component current.