ELECTRONIC PRINCIPLES - OD1647 - LESSON 1/TASK 2
The current flow in the external circuit is always due to the
negative terminals of the supply batteries to the Ntype
emitter. This combined movement of electrons is known as
emitter current (IE).
Because electrons are the majority carriers in the N material.,
they will move through the N material emitter to the emitter
base junction. With this junction forward biased, electrons
continue on into the base region. Once the electrons are in the
base, which is a Ptype material, they become minority carriers.
Some of the electrons that move into the base recombine with
available holes, For each electron that recombines, another
electron moves out through the base lead as base current IB