## Monday, March 18, 2013

### Lesson 3- Basic electronics

Electronics are any device that runs on Electricity. Essentially, Electricity is the flow of electrons through a conductor. There are 3 key things in electronics that are the most fundamental principals, which are all related to each other. I'm going to relate them to water flowing through a hose, which isn't a completely unrelated concept.

Current- This is the amount of flow of water through the hose
Voltage- This is the pressure of the water through the hose
Conductance- This would be diameter of the hose. The inverse of this is more commonly used, resistance, which would be large for a small hose and small for a large hose.

As you can imagine, if you have more pressure, more water will flow through the hose. Likewise, a bigger hose means more water will flow through it. The exact relationship between these in electronics is called Ohms Law. This is:

Voltage= Current * Resistance

This formula is one of the most important for electronics as a whole, and for the Amateur Radio tests in particular. Also of great importance is calculating the amount of power in a circuit. This formula is:

Power = Voltage * Current

This formula can be used to find the amount of power a circuit dissipates, the amount of heat dissipated, or the power taken up by a radio. There are a multitude of test questions on this subject.