Abstract: Based on the working principle of the high-voltage stable power supply of the PWM-Buck electron beam welder (EBW), this paper comprehensively analyzes the influence of various characteristic parameters of the Hall sensor voltage measurement system on the performance of the PID control system of the stable power supply through SABER simulation. It proposes some basic rules and issues that must be considered when designing or applying Hall sensors, laying the foundation for designing a high-performance PWM-Buck EBW-HVS. Keywords: Electron beam welder; Hall sensor; PWM-Buck; PID control 1 Introduction Electron beam welders (EBW) are widely used in welding high-precision military and civilian products such as automobiles, ships, nuclear reactors, and aerospace due to their high power, excellent welding performance, and cost-effectiveness. This equipment requires a high-performance stable high-voltage source (HVS) to accelerate the electron beam and ensure welding quality. A medium-capacity EBW stable HVS outputs 60kV with a voltage regulation accuracy of 1% and an operating current of 0-300mA. Traditional HVS voltage regulation modes include power frequency chopper regulation and three-terminal linear regulation. The former suffers from excessive ripple and a complex transformer structure; the latter is inefficient and has a complex oil-cooling mechanism. Therefore, a high-frequency PWM-Buck type switching power supply-type HVS is proposed, employing pulse width modulation (PWM) voltage regulation. PWM-Buck type HVS operates in a high-voltage, high-power mode, posing serious safety hazards to personnel and equipment, and also exhibits strong electromagnetic interference. Therefore, for the HVS's weak-current control system to operate reliably, it must be isolated from the main circuit's strong and weak currents, and this isolation must not affect measurement accuracy. Commonly used opto-isolation measurement circuits are not only structurally complex but also affect the main circuit's operation, are inconvenient to install, and have poor linearity for low-current measurements. The new generation of closed-loop Hall sensors offers excellent electrical isolation performance and features wide bandwidth, fast response, high accuracy, good linearity, easy installation, no energy consumption of the main circuit, no impact on the main circuit's operation, and AC/DC parallel measurement capabilities. Therefore, its application performance is significantly superior to opto-isolation. This paper presents the working principle of a PWM-Buck type HVS. Through SABER simulation, it comprehensively analyzes the impact of Hall sensor (transmitter) characteristic parameters on the HVS control system, and proposes rules and key considerations for designing or applying Hall sensors (transmitters), laying the foundation for designing a high-performance EBW-HVS. For details, please click: Application of Hall Sensors in Buck Type EBW High Voltage Stabilized Power Supplies.