BUY BU2527AX https://www.utsource.net/itm/p/11534588.html

Description: The BU2527AX is a high voltage NPN Darlington transistor in a TO-3PF package. Features: High voltage: VCEO = 500 V High current: IC = 5 A High DC current gain: hFE = 1000 Low saturation voltage: VCE(sat) = 1.2 V High switching speed Applications: Switching applications High voltage power supplies Motor control Lamp ballast Audio amplifiers (For reference only)