This arrangement determines the direction of conventional current or electron flow and the polarities of any voltages applied. Concerning the direction of conventional current flow, the arrow at the emitter terminal of the transistor representation for both types of transistors points towards the direction of conventional current flow and therefore offers an important reference. The methods of determining the type of transistor and material used to make it are demonstrated in this experiment including how to identify the three terminals of a transistor (Gates 2012).
Transistors are categorized according to: type (PNP or NPN); material used (silicon or germanium); and major application (high frequency, switching or high and low power). Most transistors are labeled with a number used to identify them. They are packaged into different sizes and configurations depending on application requirements. Transistor packages protect them, provide a means of making electrical connections to the three terminals, and act as heat sinks preventing heat damage.
The relationship between the currents and the voltages related to a transistor under different conditions of operation determine its performance. These relationships are collectively known as the characteristics of the transistors. These characteristics are published by the manufacturer of a particular transistor in a specification sheet that accompanies the device when purchased. ...Show more