Electronics Quick Guide

Resistor Color Codes

Transistor Basics

Symbols for Bipolar Transistor and Fets
  • Transistors have 3 pins: collector,base and emitter . They are current amplifiers. As in the diagram above transistors come in NPN and PNP types. For a NPN transistor to be turned on the base voltage must be greater than the emitter voltage and vice versa for the PNP type. Transistors have 3 regions of operation:
  • Saturation: Transistor fully turned on
  • Cut-off: Transistor fully turned off
  • Active: Anywhere in between the Cut-off and Saturation region.