| 摘要 |
PURPOSE:To perform excellent control without using a Hall element or the like, by using as a rotation position signal for a permanent magnet rotor the output of a calculation circuit which picks out a portion of the counter electromotive force of a stator winding and performs time-dependent addition and subtraction. CONSTITUTION:Stator windings 2a-2c are energized through driving transistors 3a-3c. The turn-off regions of the counter electromotive forces of the windings 2 are picked out by rectifier circuits 30a-30c. The output half waves of the rectifier circuits are applied to discharge-type voltage/current conversion circuits 31a-31c and suction-type voltage/current conversion circuits 32a-32c to charge and discharge time-dependent integration capacitors 33a-33c to which a DC voltage bias 34 is being applied. Driving currents are sequentially changed-over by a differential amplifier circuit 35 on the basis of position signals stored in the capacitors 33 to drive a motor through a drive circuit 38. This results in dispensing with a Hall element or the like, facilitating manufacture and improving control accuracy. |
