The BT151S-650S from WeEN Semiconductors is a Silicon Controlled Rectifier with Breakover Voltage 650 V, Breakover Current 90 A, Gate Trigger Voltage 0.1 to 1 V, Gate Trigger Current 0.0002 A, Temperature Operating Range -40 to 150 Degree C. Tags: Surface Mount. More details for BT151S-650S can be seen below.