Abstract : This paper proposes a technical transformation method for a type of equipment imported from Japan in the 1980s, which mostly uses gear motors and small-scale integrated circuits for control. The process of transforming this imported equipment—a cathode welding machine—is described in detail. Keywords : Gear motor; Programmable logic controller (PLC); Frequency converter; Equipment utilization rate. Currently, most black-and-white picture tube electron gun production lines imported in China in the 1980s use small-scale integrated circuits for their component manufacturing and assembly equipment and control systems. While this structure is characterized by low cost, with the increasing demand in the electron gun market, production is gradually moving towards high-input, high-output, high-performance, and serialized products, as well as providing high-quality customer service. The disadvantages of its control system in terms of stability are becoming increasingly apparent: low equipment utilization rate, high maintenance difficulty, long maintenance time, and even becoming a bottleneck for the entire production line, seriously restricting production development and product quality improvement, and hindering sales and market follow-up. However, using programmable logic controllers (PLCs) and frequency converters can effectively solve this problem. Using a PLC has the following advantages: ① Convenient programming; programs can be modified on-site. ② Modular structure for easy maintenance. ③ Higher reliability than integrated circuit devices, while smaller in size. ④ Data can be directly transmitted to the management computer. ⑤ Outputs include OC gate, RELAY, and TRC options, enabling direct driving of solenoid valves, contactors, etc. ⑥ Expansion requires only minor changes to the existing system. ⑦ User program storage capacity can be expanded to at least 4K. Using a frequency converter has the following advantages: ① Continuously adjustable speed. ② Uses ordinary three-phase AC motors. ③ Excellent drive and braking performance with accurate positioning. ④ Extremely low failure rate. [b][align=center]For more details, please click: Application of Programmable Controllers and Frequency Converters in Equipment Retrofitting[/align][/b]