MOTOR DRIVING DEVICE

PROBLEM TO BE SOLVED: To suppress loss of the functions of a bearing in a motor driving device 10. SOLUTION: When the output voltage of a regulator circuit 31 rises in conjunction with turn-on of an ignition switch IG, the following takes place: a current flows from the ignition switch IG side to a resistance element R3 through the regulator circuit 31 and a capacitor C1. The voltage level of the voltage of a control terminal Ta of a drive circuit 30 is kept equal to or higher than a threshold value xV for a period Ton1 by this current. For this reason, the drive circuit 30 drives a brushless motor 1. Even when an electronic control unit 20 does not output a pulse signal Pa, therefore, the brushless motor 1 is rotated in conjunction of turn-on of the ignition switch IG. As a result, to a large flaw is prevented from being produced in one place in a bearing. COPYRIGHT: (C)2007,JPO&INPIT