FET Fundamentals Unit 6 – Unijunction Transistors
UNIT 6 – UNIJUNCTION TRANSISTORS
UNIT OBJECTIVE
At the completion of this unit, you will be able to demonstrate the dc and ac operation of a
relaxation oscillator by using a unijunction transistor test circuit.
UNIT FUNDAMENTALS
This is the schematic symbol of a unijunction transistor (UJT).
The construction (simplified) of a UJT is shown. A unijunction transistor is a two-layer device. It
is constructed with P type material and N type material.
The large bar of N type semi-conductor material joins with a small portion of P type material.
The junction of both materials forms a PN junction.