This post explains for the transistor.
The Part Number is 2SD2375.
The function of this semiconductor is 80V, 3A, NPN Transistor.
The package is TO-220D Type.
Manufacturer: Panasonic Semiconductor
Preview images :
The D2375 is Silicon NPN triple diffusion planar type transistor.
Absolute maximum ratings ( Ta=25°C )
1. Collector to Base Voltage: Vcbo = 80 V
2. Collector to Emitter Voltage: Vceo = 60 V
3. Emitter to Base Voltage: Vebo = 6 V
4. Collector Current: Ic = 3 A
5. Collector Dissipation : Pc = 2 W
6. Junction Temperature: Tj = 150°C
7. Storage Temperature: Tsg = -55 ~ +150°C
1. High forward current transfer ratio hFE which has satisfactory linearity
2. Full-pack package which can be installed to the heat sink with one screw
1. Power amplification with high forward current transfer ratio