Patent ID: 6274993
Filing Date: 2001-08-14
Classification: H02P

Abstract:
A motor drive apparatus comprising:a motor having an output shaft to which a driven object is coupled to be position-controlled;a drive circuit which supplies electric current to the motor;position detection means which detects a position of the driven object;control means which receives a position detection signal from the position detection means and produces a drive command signal to the drive circuit to control the position of the driven object to a target position, the drive command signal being for starting to drive the motor at rest and supplying the current in a reverse direction for braking;current detection means for detecting the current supplied to the motor;current supply restriction means for restricting the current supply to the motor when the current value detected by the current detection means is in a large current supply condition and the condition continues for more than a predetermined time period; andreset means for resetting a time counting operation of the predetermined time period of the current supply restriction means in response to a detection of switching of current supply directions caused between motor drive start and braking.