MOTOR DRIVE CIRCUIT

PROBLEM TO BE SOLVED: To commonly use an armature coil irrespective of the type of wire connection even if the wire connection is of a type of star connection or independent connection. SOLUTION: A pair of transistors of each phase of a drive circuit 12 are separated and made independent as respective terminal portions 22A to 22F of an external output unit 22, so that the drive circuit can be commonly applied to motors different in connection forms. When a star-connection three-phase brushless motor is used, the separated terminals are short-circuited, while when an independent-connection three-phase brushless motor is used, the respective terminals are wired independently. Furthermore, regenerative diodes are provided so as to be capable of regenerating power, independently of transistors Tr, thus even if the drive circuit is applied to the independent-connection three-phase brushless motor, the transistors Tr is not destroyed at all by a counter electromotive force (current) of the armature coils when transistors Tr are switched from on to off. COPYRIGHT: (C)2006,JPO&NCIPI