2N4990.

THYRISTOR 30V 0.175A TO92; Peak Repetitive Off-State Voltage Vdrm:-30V; Gate Trigger Current Max Igt:5mA; Current It av:175mA; On State RMS Current IT(rms):175mA; Thyristor Case Style:TO-92; No. of Pins:3Pins; Peak Non Rep Surge Current Itsm 50Hz:1A; Holding Current Max Ih:0.75mA; Gate Trigger Voltage Max Vgt:-; Operating Temperature Max:-; Product Range:-; MSL:-; SVHC:No SVHC (12-Jan-2017); Thyristor Case:TO-92