Simple Diagram Of Transistor. They are not always set out as shown in the diagrams to the left and right although the tab on the type shown to the left is usually next to the emitter. The diagram shows the two current paths through a transistor.
First and second stages are pre amplifiers and third is the output stage. A simple way you can think of it is to look at the transistor as a relay without any moving parts. The base which is the lead responsible for activating the transistor.
This circuit is easy to make and very convenient for testing transistors.
These multimeters and transistor testers are complex to understand and design. A very simple low power three stage transistor amplifier circuit is shown below. The base which is the lead responsible for activating the transistor. A compilation of important assorted transistor simple circuits to build has been included here.
