2N2222A by Texas Instruments is a small signal NPN bipolar junction transistor (BJT) with a max collector-emitter voltage of 40V and a max collector current of 0.8A. It is commonly used for switching applications due to its fast turn on/off times (35ns/285ns) and high transition frequency (300MHz).
MAGNETIC FIELD SENSOR,HALL EFFECT; Mounting Feature: THROUGH HOLE MOUNT; No. of Terminals: 3; Output Type: ANALOG CURRENT; Package Shape or Style: RECTANGULAR; Output Range: 25mA;