This part is a kind of semiconductor called 2SD198.

Function of this product has SILICON POWER TRANSISTOR.

Manufacturers : SavantIC

Image and pinout :

Some of the text within the PDF file :

SavantIC Semiconductor Product Specification Silicon NPN Power Transistors 2SD198 DESCRIPTION ·With TO-3 package ·High breakdown voltage APPLICATIONS ·voltage regulator ·Inverters ·Switching mode power supply PINNING(see Fig.2) PIN 1 2 3 Base Emitter Collector Fig.1 simplified outline (TO-3) and symbol DESCRIPTION Absolute maximum ratings(Ta= ) SYMBOL VCBO VCEO VEBO IC PC Tj Tstg PARAMETER Collector-base voltage Collector-emitter voltage Emitter-base voltage Collector current Collector power dissipation Junction temperature Storage temperature TC=75 CONDITIONS Open emitter Open base Open collector VALUE 300 300 6 1 25 165 -55~200 UNIT V V V A W SavantIC Semiconductor Product Specification Silicon NPN Power Transistors CHARACTERISTICS Tj=25 unless otherwise [ ... ]

2SD198 PDF Datasheet Download