The principle of motor drives is powered by unipolar DC power supply. As long as the windings of each phase of the stepper motor are energized in the appropriate timing, the stepper motor can be turned on step by step. AC synchronous motor needs to feedback the speed, position or torque reference value to the supporting drive through the sensor and encoder at the rear end of the motor, which can be divided into pendant clamps, tensile clamps, connecting fittings, connecting fittings, connecting fittings, protective fittings, equipment wire clamps, T-type wire clamps, busbar fittings, pulling fittings and other categories according to the function and structure.

The unmanned vending machine shipping gearbox is a fittings that can be used to fasten the terminal to fix it on the tensile insulator string, and also for the fixing of the lightning rod terminal and the anchoring of the wire. Anchoring fittings bear all the tension of wires and lightning protection wires, and some anchoring fidants also act as conductors. The soft bus bar is connected to the outlet terminal of the electrical equipment, and the T connection of the conductor and the parallel connection without bearing force, etc.

These connections are electrical contacts, so the contact fittings are required to have high electrical conductivity and contact stability. This kind of fittings are used for the fixation and connection of various hard busbars or soft busbars and pillar insulators in power distribution devices, and most of the fixed fittings are not used as conductors, only for fixing, support and suspension. However, since these fittings are used for high currents, all components have no hysteresis loss.