What is transistor and how can it operate and what are its types?

A transistor is a semiconductor device used to amplify & switch electronic signals. The name transistor comes from the 'trans' of transmitter and 'sister' of resistor. Transistors are used in a wide array of electronic equipment, ranging from pocket calculators and radiOS to industrial robots and communications satellites.

There are two types of transistor viz:

• Primary type transistor-The primary type of transistor in use is known as a bipolar junction transistor, which consists of three layers of semi-conductor material, two of which have extra electrons, and one which has gaps in it. The two with extra electrons (N-Type) sandwich the one with gaps (P-Type). These bipolar transistor are divided into NPN and PNP types. All these primary type of transistor are shielded to protect from light source if it is not shielded from light then the light may be used to open or close the gate, in which case it is referred to as a phototransistor, functioning as a highly-sensitive photodiode.
• Secondary type transistor-The secondary type of transistor is known as a field-effect transistor, and consists either entire of N-Type semi-conductive material or P-Type semi-conductive material, with the current controlled by the amount of voltage applied to the transistor.

General process of Transistor Working

Each transistor has a store of electrical charge that remains there until it is turned on. In order to turn on a transistor, a small electrical charge needs to enter it via the base. When this happens, the electrical charge opens up the collector, and a more powerful charge leaves through the emitter. Electrical charge is measured in milliamps, and the typical transistor will multiply an electrical charge by one hundred times the number of milliamps it has. The electrical charge that is emitted by a transistor will then flow through a route designated by however the component it is attached to is designed. Complex electronics have many paths that electrical currents need to travel on, and therefore many transistors will be needed in order to constantly supply enough power to work the device.