BUY BT137-800 https://www.utsource.net/itm/p/11606988.html

Description: The BT137-800 is a three-terminal silicon controlled rectifier (SCR) with a sensitive gate. Features: 800V blocking voltage 4A average on-state current Low gate trigger current Low thermal resistance High surge current capability High commutation capability High temperature stability Applications: Motor control Lamp dimming Heating control Power switching (For reference only)