| 摘要 |
PURPOSE:To improve steady characteristic and starting characteristic by providing a gain switching circuit for a motor driving amplifier. CONSTITUTION:Phase control system for a motor 1 is constituted of a phase control loop and a speed control loop. The phase control loop is constituted of a loop of a phase difference detector 6, a phase characteristic compensator 7 and a phase error amplifier 8, while the speed control loop is constituted with a speed error detector 10. Signals fed from both loops are added 22 and fed to a switch 12 for a starting voltage setter 20 in order to perform drive control through a motor driving amplifier 21. The amplifier 21 comprises a comparator 14, a switch 15, current error amplifiers 16, 17, and a motor drive 18, and switching of gain of the error amplifiers 16, 17 is carried out according to the rotary speed of the motor 1. |
