2SD811 Bipolar Transistor

• Type: NPN
• Collector-Emitter Voltage, max: 400 V
• Collector-Base Voltage, max: 900 V
• Emitter-Base Voltage, max: 6 V
• Collector Current − Continuous, max: 6 A
• Collector Dissipation: 50 W
• DC Current Gain (h_fe): 10 to 40
• Transition Frequency, min: 5 MHz
• Operating and Storage Junction Temperature Range: -55 to +150 °C
• Package: TO-3

Here is an image showing the pin diagram of this transistor.Sometimes the "2S" prefix is not marked on the package - the 2SD811 might only be marked "D811".You can replace the 2SD811 with the 2N6673, 2N6678, 2SC2429, 2SC2429A, 2SC3044, 2SC3044A, 2SC3045, 2SC3058, 2SC3058A, 2SD821, 2SD822, 2SD871, BUX48, BUX48A, MJ12021, MJ12022, MJ16006, MJ16008, MJ8504 or MJ8505.