What are bipolar transistors?

Bipolar transistors refer to specially designed electronic semiconductor devices, which are used primarily to amplify electrical current flow. They are three-pin, solid state devices that can function as a switch as well.

Types of bipolar transistors

Bipolar transistors are chiefly available in two different types, such as the PNP transistor or Positive-Negative-Positive transistor and the NPN transistor or Negative-Positive-Negative transistor. 

Other than these, there are two different varieties of bipolar transistors available in the market today as well. These are:

• Digital transistors: This variety of bipolar transistors consist of a type of semiconductor material, like silicon, that is capable of conducting the electric current by offering little resistance. Digital transistors usually possess three terminals, to establish seamless connection with an external circuit.
• UJT transistors: These varieties of bipolar transistors are built with an N type lightly doped silicon and a small piece of P type heavily doped material. The N type silicon bar provides very high resistance. 

Applications

Bipolar transistors are exceedingly used across the electronic industry. As such, they have a big part to play in almost every other sector as well. But most importantly, their typical application can be found in electronic circuits and designs. Bipolar transistors are a highly effective device for amplifying different types of electrical signals.