EXPERIMENT 6

TRANSISTORS: There are two types of transistors positive (NPN) and negative (PNP) Using a multimeter in diode test mode you can determine the base emitter and collector also if its NPN or PNP. A NPN or PNP transistor is found when you get two readings on your meter with it having one leg in common. That one leg in common will decide what charge it has. If the common leg was when the red lead was touching it, it will be a NPN transistor. If it is the black lead it will be a PNP transistor. (the common leg will always be the base) To find the collector and emitter normally the highest reading of the two will indicate the emitter to base and the lower one will be collector to base. Transistors are used as a switch to use low current to switch high current. eg low current is passed through base to emitter and opens up the gate(so to speak) and lets the high current from the collector flow passed through the (gate) out to the emitter. (NPN transistor)