This post explains for the MOSFET.
The Part Number is 2SK4097.
The function of this transistor is N-Channel MOSFET.
Manufacturer: Sanyo Semicon Device
Preview images :
The K4097 is 500V, 9.5A, N-Channel Silicon MOSFET.
• Low ON-resistance, low input capacitance, ultrahigh-speed switching.
• Adoption of high reliability HVP process.
• Attachment workability is good by Mica-less package.
• Avalanche resistance guarantee. […]
Absolute Maximum Ratings (Ta = 25°C)
1. Drain to source voltage: VDSS = 500 V
2. Gate to source voltage: VGSS = ± 30 V
3. Drain current: ID = 9.5 A
4. Allowable Power Dissipation: Pd = 2 W
5. Channel temperature: Tch = 150 °C
6. Storage temperature: Tstg = -55 to +150 °C
1. General-Purpose Switching Device