| 摘要 |
PURPOSE: To realize high speed rotary driving of a motor by additionally providing only a simple external circuit and utilizing a conventional motor drive circuit IC employing the motor drive system having no position detecting element as it is with no modification. CONSTITUTION: A counter electromotive force division circuit 18 is provided between stator windings 2a, 2b, 2c and driving transistors 7a, 7b, 7c. When a permanent magnet rotor 1 is rotary driven, counter electromotive forces induced in the stator winding 2a, 2b, 2c are divided by means of resistors 15a, 16a, 15b, 16b and 15c, 16c and fed to driving transistors 7a, 7b, 7c through transistors 17a, 17b, 17c. The transistors 17a, 17b, 17c have collector terminals connected with the stator winding 2a, 2b, 2c which are fed with currents from the driving transistors 7a, 7b, 7c through the transistors 17a, 17b, 17c. |
