This post explains for the MOSFET.
The Part Number is K2769, 2SK2769.
The function of this semiconductor is 900V, 3.5A, N-channel MOSFET.
Manufacturer: Fuji Semiconductors
Preview images :
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Description
The K2769 is 900V, 3.5A, N-Channel MOSFET.
Features
1. High Speed Switching
2. Low On-Resistance
3. No Secondary Breakdown
4. Low Driving Power
5. High Voltage
6. VGS = ± 30V Guarantee
7. Repetitive Avalanche Rated
[…]
Absolute Maximum Ratings (Ta = 25°C)
1. Drain to source voltage: VDSS = 900 V
2. Drain current: ID = 3.5 A
3. Gate to source voltage: VGSS = ± 30 V
4. Max. Power Dissipation: Pd = 40 W
5. Channel temperature: Tch = 150 °C
6. Storage temperature: Tstg = -55 to +150 °C
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Applications:
1. Switching Regulators
2. UPS
3. DC-DC converters
4. General Purpose Power Amplifier