Patent ID: 7408318
Filing Date: 2008-08-05
Classification: H02P

Abstract:
1. A motor drive unit adapted to generate a motor drive signal for driving a motor when said motor is in rotational motion, but, when a motor lock-up condition of said motor is detected, stop said motor drive signal in dormant periods and generate said motor drive signal in startup trial periods, said startup trial periods interlaced with said dormant periods, said motor drive unit characterized by comprising: a capacitor, which is charged or discharged to generate a voltage signal in accord with the electric charge stored in said capacitor; a hysteresis-type comparator for generating a comparison output upon detection of said voltage signal reaching a predetermined threshold level; a first charging circuit for charging said capacitor with first charging current when the drive current supplied to said motor has exceeded a predetermined level; and a first discharging circuit for discharging said capacitor with said first discharging current based on said comparison output, and characterized in that said dormant periods being periods in which said comparison output is generated, and said startup trial periods being periods in which said comparison output is not generated.