This part is a kind of semiconductor called D1577.
Function of this product has 2SD1577.
Manufacturers : Wing Shing Computer
Image and pinout :
Some of the text within the PDF file :
2SD1577 GENERAL DESCRIPTION Silicon Diffused Power Transistor Highvoltage,high-speed switching npn transistors in a plastic envelope with integrated efficiency diode,primarily for use in switching power circuites of colour television receivers QUICK REFERENCE DATA SYMBOL TOP-3Fa CONDITIONS VBE = 0V TYP VCESM VCEO IC ICM Ptot VCEsat Icsat VF tf PARAMETER Collector-emitter voltage peak value Collector-emitter voltage (open base) Collector current (DC) Collector current peak value Total power dissipation Collector-emitter saturation voltage Collector saturation current Diode forward voltage Fall time Tmb 25 IC = 3.0A; IB =0.8A f = 16KHz ICsat = 3.0A; f = 16KHz - MAX 1500 600 3 6 40 5 1.0 UNIT V V A A W V A V s LIMITING VALUES SYMBOL VCESM VCEO IC ICM IB IBM Pt [ ... ]