Very basics of Transistor-Interesting

What is Transistor?
         A Transistor is an electronic device that replaced the bulky and high power consuming devices called vaccum triodes.

Types:
      NPN-P type is sandwiched between n.

                                     

Construction of Transistor


Emitter:
          -One side of transister and always heavily doped and supplies charge carriers.
Base:
          -Middle region of the transistor.Lightly doped than other two.
Collector:
         -Region situated opposite to emitter.Collects the charge carriers that cross the base region after emanating from the emitter.
Emitter Junction:
         -PN junction formed by the emitter and base.
Collector Junction:
         -PN junction formed by the collector and base.




Transistor Action:
1)UnBiased:
       -Two depletion regions formed around collector and emitter.
       -No currents flows when there is no supply.

                                                                              




















2)Biased:
        -When two junctions are biased using external DC supply.

                                                     











-It has 3 modes of operation.

• Active
• Saturation
• Cut-off                                      

     NOTE: The explanation of the modes of operation will be posted soon.