Electrical proportional valves are developed with the rapid development of microelectronics and computer technology to meet the needs of modern industrial production automation. At present, due to the characteristics of low cost, strong anti pollution ability, good dynamic characteristics, high control accuracy, and mature application of electrical proportional valves, the application prospects of this type of system are very broad.

The dispensing machine system is powered by compressed air, and the device mainly consists of five parts: the main controller, storage module, communication module with the lower computer input/output control module, and keyboard/display module. The main controller realizes data processing and outputs control signals to control the driving circuit of external devices; The storage module is used to store data; The communication module with the lower computer realizes data exchange and command control between the motherboard and the lower computer; The input/output control module is used to drive the switches of electrical proportional valves and solenoid valves; The keyboard/display module is used to display parameter settings and data display.

The pneumatic control system is an important component of the dispensing device, and its design will directly affect the quality of dispensing and the consistency and uniformity of the dispensing process. The precise control of the opening of the electrical proportional valve is achieved through programming, thereby controlling the size of the airflow passing through it and achieving precise control of dispensing.