This is one of the transistor types.
This post explains for the transistor NPN Transistor.
Part Number : D718
Function : NPN TRIPLE DIFFUSED TYPE Power Transistor
Manufacturers : Toshiba
Package : TO-247, TO-3, 2-16B1A Type
See the preview image and the PDF file for more information.
Image :
Description :
This transistor designed for use in general-purpose amplifier and switching application.
D718 Features
1. Complementary to 2SB688
2. Recommended for 45 ~ 50W audio frequency amplifier output stage.
3. AUDIO FREQUENCY POWER AMPLIFIER APPLICATIONS.
Maximum Ratings ( Ta=25’C )
1. Collector-Base Voltage : Vcbo = 120V
2. Collector-Emitter Voltage : Vceo = 120V
3. Emitter-Base Voltage : Vebo = 5V
4. Collector Current : Ic = 8A
5. Base Current : Ib = 0.8A
6. Collector Power Dissipation : Pc = 80W
Pinout
Other data sheets within the file : 2SD718