TRANSISTOR

What is a Transistor?

A Transistor is a semi-conductor device that is made up of two P-N junction i.e (P-N-P or N-P-N ) sandwiched together which can either be an npn or pnp configuration.

A Transistor has several application. the art of electronics lies solely on its mode of operation. series (thousands) of transistors brought together in a single package results to what is known as integrated circuit (I.C). this is the fundamental and important component in electronics today. large scale of transistor, which gives rise to micro chips is generally use in all aspect of electronics, be it radio communication, micro electronics and so forth.

A Transistor is made up of three terminals namely The Base, Collector and emitter. an npn transistor uses a positive supply for its operation while pnp transistor type uses a negative supply for its operation.

When a transistor is not conducting, it is said to be at "cut-off" i.e when its collector potential equals to the supply voltage. while when it is conducting, it is said to be saturated i.e when the collector potential is bottomed or dropped to the emitter.

Transistor, could be use as a switch. In Telecommunication, transistors forms part of the switching been done in circuits. A little current in mA (milli-amperes) at its base can cause a large amount of current to flow from the collector to the emitter.

These implies that if a load is connected across the collector, a small base current in mA can cause the load to function (activate or become opeational) as large amount of current will flow across the load from the positive rail or terminal of the power supply. It can be use to operate an alarm system or drive a light emitting diode or even relays in activating heavy duty loads in industrial environment as seen in the diagram in this article.

The application of a transistor switch is enormous. But due to its switching speed, in applications requiring speed in nano seconds, other types of transistor are employed such as Field Effect Transistors and so on. Power consumption is small in the range of milli-watt. Combination of transistors circuit can be made to form complex application such as designing circuits such as remote operated fan speed regulator where the speed coils of the fan regulator are switched by a transistor switch in energizing a relay.

Watch out for my up coming articles on how to construct basic circuit in electronics project in which you can use as your final year project in school.

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