Transistor

 
The two main types of transistors are P-N-P and N-P-N. A transistor consists of three leads, which are
  • Base the activating lead
  • Emitter the Negative lead
  • Collector the Positive lead
npn and pnp Transistor
 
As shown above, an NPN transistor operates using positive current biased at the base, allowing current to flow from Collector to Emitter. A PNP transistor operates using negative current biased at the base, allowing current to flow from Emitter to Collector. Thus the polarity of NPN transistor is the reverse of PNP transistor.
 
Related Information:
1. Semiconductors
2. Moores's Law


Last Revised on: March 03rd, 2012