Saturday, February 09, 2013

Short Notes on Bipolar transistors

NPN Transistor


Placing P-type semiconductor between two N-type semiconductor is NPN transistor


It operates by a small current flow from the emitter to base.current will not  flow from the emitter to the collector until a small voltage (at least 0.7 volts) is applied to the base.


Collector current is much larger than the base current.

SYMBOL



 PNP Transistor

 Placing N-type semiconductor between two P-type semiconductor is PNP transistor.


Its operation is same as NPN but reversed.The voltage relations also reversed.So to turn on the device both the collector and base must be negative.



PNP symbol

Amplification:

 Transistors are used as amplifiers to increase the input signals in TV ,stereo and others applications.It is often called as linear electronics since it contains direct relation with the input and output signal.




If the base is given with the power,it gets biased.It switch on the transistor.An increase or decrease in the input signals makes an increase and decrease in the output signal but with the signal inverse.Frequency remains the same.

Gain:

The measure of amplification is the gain.

For example, if the input signal has an amplitude of 0.2 volts, and the output signal has an amplitude of 10 volts, then:
Power gain =current gain x voltage gain.

Switching

Transistors can also be used for switching in case of digital circuits.Digital circuits needs switch on and off.

When the voltage is below 0.6v no current flows through the circuit.when transistor is not conducting ,it is said to be cut-off.


When the base voltage is about 0.85 volts, sufficient base current flows to turn the transistor fully on. The collector voltage drops to approximately half a volt because of the voltage drop across the collector resistor. A transistor which is conducting the maximum current is said to be in saturation.

Transistor Application

Linear:


Amplifiers

Digital:


Computers




Courtesy:http://silver-fox.ca



Hardwork Can Never Ever Fails..
Best Luck..



2 comments:

  1. You've got finished a stunning job with you website.
    best universal remote

    ReplyDelete
  2. एसुस ने लांच किया 7वीं पीढ़ी के इंटेल प्रोसेसर युक्त नोटबुक

    Readmore todaynews18.com http://bit.ly/2j6FBZb

    ReplyDelete

Thank you for your valuable suggestion. If you feel this post useful, please share our Blog with others!!! Comments just for Backlinking your Website or Blog will be Deleted...