BD128 Bipolar Transistor

• Type: NPN
• Collector-Emitter Voltage, max: 300 V
• Collector-Base Voltage, max: 350 V
• Emitter-Base Voltage, max: 5 V
• Collector Current − Continuous, max: 0.5 A
• Collector Dissipation: 17.5 W
• DC Current Gain (h_fe): 30
• Operating and Storage Junction Temperature Range: -55 to +150 °C
• Package: TO-126

Here is an image showing the pin diagram of this transistor.You can replace the BD128 with the 2N5656, 2N5656G, 2N5657, 2N5657G, 2SC2752K, 2SC2752L, BD129, BD158, BD159, BD410, BUX86, BUX87, KSC2752O, KSC2752Y, KSE340, KSE5020-Y, MJE340 or MJE340G.