The requirement on low power and small size can be met by means of switching gyro motor, PWM amplifier, C196 MCU and PSD devices.

To improve the capability of the electric system, a three-level PWM power amplifier and Backboard of the control-box is designed, which are applicable to the bearing-less slice PM motor.

This paper give an advice that we can realize closed cycle control of feeding shaft by proportional valve and linear grid ruler instead of servo amplifier and servo motor.