The ST33 Three-Phase Silicon Controlled Rectifier (SCR) Trigger Board is equipped with a 32-bit industrial-grade high-performance microprocessor. It features a highly digital safety standard design, supporting both network remote control and on-site control. It offers open-loop voltage regulation, closed-loop constant voltage, and constant current regulation, integrating all three into one control system for SCR to achieve constant voltage limiting current or constant current limiting voltage. Fault alarms and interface parameters are displayed on an LCD screen or a touch screen with Chinese menu, and set parameters are automatically saved. The control board includes functions such as phase loss protection, soft start-up, soft shutdown, constant current output, constant voltage output, over-voltage protection, over-current protection, short-circuit protection, and working status indication.