BDT61A Bipolar Transistor

• Type: NPN
• Collector-Emitter Voltage, max: 80 V
• Collector-Base Voltage, max: 80 V
• Emitter-Base Voltage, max: 5 V
• Collector Current − Continuous, max: 4 A
• Collector Dissipation: 50 W
• DC Current Gain (h_fe): 750
• Operating and Storage Junction Temperature Range: -65 to +150 °C
• Package: TO-220

Here is an image showing the pin diagram of this transistor.The complementary PNP transistor to the BDT61A is the BDT60A.You can replace the BDT61A with the 2N6044, 2N6044G, 2N6045, 2N6045G, 2N6388, 2N6388G, 2N6530, 2N6532, 2SD1195, 2SD1196, 2SD1276A, 2SD1276A-P, 2SD1276A-Q, 2SD1277A, 2SD1277A-P, 2SD1277A-Q, 2SD1414, 2SD1415, 2SD1415A, 2SD1829, 2SD1830, 2SD1891, 2SD1891-P, 2SD1891-Q, 2SD1892, 2SD1892-P, 2SD1892-Q, 2SD2241, 2SD2495, 2SD2495-O, 2SD2495-P, 2SD2495-Y, 2SD560, 2SD560-KB, 2SD560-LB, 2SD560-MB, 2SD633, 2SD634, 2SD837A, 2SD837A-P, 2SD837A-Q, 2SD837A-R, BD647, BD649, BD651, BD899, BD899A, BD901, BDT61B, BDT61C, BDT63A, BDT63B, BDT63C, BDT65A, BDT65B, BDT65C, BDW23B, BDW23C, BDW41, BDW41G, BDW42, BDW42G, BDW43, BDW53B, BDW53C, BDW53D, BDW63B, BDW63C, BDW63D, BDW73B, BDW73C, BDW73D, BDW93B, BDW93C, BDW93CF, BDX33B, BDX33BG, BDX33C, BDX33CG, BDX33D, BDX53B, BDX53BG, BDX53C, BDX53CG, KSB601, KSB601-O, KSB601-R, KSB601-Y, KSD560, KSD560-O, KSD560-R, KSD560-Y, MJE802T, MJE803T, MJF122, MJF122G, MJF6388, MJF6388G, TIP101, TIP101G, TIP102, TIP102G, TIP121, TIP121G, TIP122, TIP122G, TIP131, TIP131G, TIP132, TIP132G, TIP141T, TIP142T or TTD1415B.