What is Transistors?

INTRODUCTION:

     The transistor was invented in 1948 by John Bardeen, Walter Brattain and William Shockley at Bell Laboratory in America. They were awarded the Nobel Prize in recognition of their contributions to physics. This invention completely revolutionized the electronic industry. Since then, there has been a rapidly expanding effort to utilize and develop many types of  semiconductor devices such as FET, MOSFET, UJT, SCR, etc.

     Transistors have replaced bulky vacuum tubes in performing many jobs. Transistors offer several advantages over tubes. A few of them are;

          (1) No heater or filament is required; hence no heating delays, and no heating power                  needed.

          (2) They are much smaller in size and are light in weight.

          (3) Very low operating volteges can be used. 

          (4) They consume little power, resulting in greater circuit efficiency.

          (5) They have long life with essentially no ageing effect.

          (6) They are essentially shock-proof.