The 2N1801 from New Jersey Semiconductor is a Silicon Controlled Rectifier with Breakover Voltage 700 V, Breakover Current 955 to 1000 A, Gate Trigger Voltage 2.5 V, Gate Trigger Current 70 mA, Temperature Operating Range -65 to 125 Degree C. Tags: Stud Mount. More details for 2N1801 can be seen below.