| 摘要 |
PURPOSE:To reduce the cost of a brushless servo motor by using an FG coil also for detecting a rotating phase, and inputting the FG voltage to a servo circuit and a driving circuit, thereby omitting the number of parts. CONSTITUTION:The frequency generating voltage of an FG coil 9 is energized at the moment that part of a power source V is determined at starting time. This voltage is input through an amplifier 21 or a servo circuit 24, a speed control amplifier 25 and an amplifier 23 to driving circuits 27, 28. After a motor is started, the coil 9 starts frequency generating in response to the rotation of the motor. The rotating phase is detected by the positional relationship between the coil 9 and a magnetic sensor 26b, and the circuits 27, 28 generate continuous driving torques. Thereafter, a 2-phase brushless motor is operated by two phase sensors made of the sensor 26b and the coil 9. |
