Transistors are common semiconductor devices that are used as a building block in a wide range of electronic devices. Transistors typically act as amplifiers, though there are several other lesser known types. Below are listed the types and their various functions and advantages.

Field-Effect Transistor. A field effect transistor, or FET, as it is referred to in its classification, is also referred to as a unipolar transistor. The FET consists of four terminals; source, gate, drain, and body. FETs are further divided into two families which are junction FET (JFET) and insulated gate FET (IGFET). IGFET, or more commonly know as MOSFET (metal-oxide-semiconductor FET), are especially useful for high frequencies such as microwaves, up to several GHz.

Bipolar Junction Transistors. Bipolar Junction Transistor (BJT) was the first transistor to be massed produced. It consists of three terminals including emitter, base, and collector. The p-n junctions of the terminals within the BJT create an exponential relationship that gives BJT a much higher mutual conductance than FET.

Unijunction. The Unijunction Transistor or UJT, has three terminals Base 1 and Base 2, and the Emitter, yet only one junction, hence the name. The PUT, or Programmable Unijunction Transistor, has an Anode and Cathode connected to the junction layer and a gate. Though somewhat different than the UJT, it does perform a similar function.

About the Author

Angela Oliver is an author for HRent.com. H and R Enterprises specializes in the distribution of hard to find and obsolete electronic components. Visit the site to view a complete inventory of electronic components including transistors.