. Usefulness
-A transistor is a small electronic device that can cause changes in a large electrical output signal by small changes in a small input signal.
-A transistor consists of three layers of silicon or germanium semiconductor material. Impurities are added to each layer to create a specific electrical positive or negative charged behavior.
- "P" is for a positive charged layer and "N" is for a negative charged layer.
-Transistors are either NPN or PNP in the configuration of the layers. There is no particular difference here except the polarity of voltages that need to be applied to make the transistor operate.
-The weak input signal is applied to the center layer called the base and usually referenced to ground which is also connected to the bottom layer called the emitter. The larger output signal is taking from the collector also referenced to ground and the emitter.
3.2. Description of the transistor
A bipolar junction transistor consists of three regions of doped semiconductors. A small current in the center or base region can be used to control a larger current flowing between the end regions (emitter and collector).
The transistors Structure
