Good afternoon, someone from the classmates who will help me find the most accurate replacement I could find for the transistor 6N65K3 As I see your data are: STF6N65K3 MOSFET. Datasheet Equivalent. Replacement. Spec Sheet Main features Part Number: STF6N65K3 FET type: MOSFET Transistor polarity: MAXIMUM NESPECIFICATIONS Total device dissipation (Pd): 30 W Drain-source voltage (Vds): 650 V Gate-source voltage (Vgs): 30 V Continuous drain current (Id): 5.4 Maximum operating temperature (Tj): 150 ° ELECTRICAL CHARACTERISTICS Gate-source threshold voltage Vgs (th): 4.5 V Gate load (Qg): 35 n RDS-source drain resistance (on): 1.3 Ohm Packaging / Case: TO220FP and I have the BUL312FP at hand and its data are: BUL312FP. Datasheet Equivalent. Replacement. Spec Sheet Main features Part Number: BUL312FPM Material: Yes Transistor polarity: NPN MAXIMUM SPECIFICATIONS Total device dissipation (Pc): 36 W Collector-base voltage (Vcb): 1150 V Collector-emitter voltage (Vce): 500 V Transmitter-base voltage (Veb): 9 V Current Maximum DC collector (Ic): 5 AT Maximum operating temperature (Tj): 150 ° ELECTRICAL CHARACTERISTICS Continuous current gain (hfe): 10 Packaging / Case: TO220FP P.S. I do not understand much about the references ... hehehehehehe