TRANSISTOR



Transistor is perhaps the most important of electronic components because of which all modern electronics works. A transistor is a semiconductor device commonly used to amplify or switch electronic signals. It’s a Device with three terminals where one terminal can be use to control the flow of current through the other two terminals. The three terminals are Emitter, Base and Collector. Its major use is as amplifier to boost various signals as well as to perform automatic switching.


There are 2 types of transistors


NPN


NPN Transistor Symbol

When base of n-p-n is connected with logic high voltage (positive voltage) then it short circuits emitter and collector (SWITCH ON). When base of n-p-n is connected with logic low voltage (Ground of Supply) then it open circuits both emitter and collector (SWITCH OFF).


PNP



PNP Transistor Symbol

When base of p-n-p is connected with logic high voltage then it opens circuit’s emitter and collector (SWITCH OFF). When base of p-n-p is connected with logic low voltage then it short circuits both emitter and collector (SWITCH ON).


Another point you should keep in mind is that the arrow always points in the direction of positive charge flow, or from the P to N sections, no matter whether the P section is the emitter or base.


Notation aside, the three pins – base, emitter, collector – are typically labeled on the data sheet for a transistor

Connection for N-P-N transistor


NPN Transistor as Switch

  • Device power to whatever power source I want to use

  • Device ground to the collector on my NPN transistor

  • Transistor emitter to “real” ground.

Connection for PNP transistor


PNP Transistor as Switch

Example of Transistor with Buzzer


Buzzer as Switch

Commonly used Transistors and their pin identifications



BC548/BC547 :-- NPN

BC548 NPN Type Transistor


BC557 :-- PNP


BC557 PNP Type Transistor


2N3904 :-- NPN 


2N3904 NPN Transistor

SL100  :-- NPN


SL100 NPN Type Transistor

Adress

Vidya Robotics,

Plot no 22 Ashok Nagar Garkheda Road,Near Manik Hospital 

Aurangabad

431001

Courses 

Contact Info

info(at)vidyarobotics.com

vidyarobotics(at)gmail.com

9689068780


 

Stay In touch 

Become Our Bestie!

  • LinkedIn Social Icon
  • White Facebook Icon
  • White YouTube Icon