First, you need to know what you are doing and what I’m talking about later on. I personally started out as a young boy with a 2000 in 1 electronics kit available at Radio Shack, but if you don’t want to do that I’ll try and explain the best that I can. Get an electronics book! Learning how circuits are laid out and how the basic physics, principles play a part in them is essential. I started in the 11th grade and it only took a month or two to get down the basics: resistors, capacitors, transistors, solenoids, DC, AC, and formulas that explain them. I read the book, Electronics by Charles A. Schuler (Might be the book???). If you can get this book, it helps a lot!
If you wanted to start out the best way possible, I would obtain either a 2000 in 1 Electronics Kit or get a few items, like a bread board, wire, different resistors, capacitors, batteries, battery connectors, and some LEDs. The stuff you can learn with this is limitless! It might be a good idea to find out how all of these items work though.
Circuits:
A basic circuit is a closed loop that contains a power source, like a battery, and some resistance. A wire can create resistance (very little, not even worth measuring), so a wire connecting one terminal (+) to the other (-) would make a complete circuit.
Voltage:
Voltage is the measure of potential that is across a given part of a circuit, and is measured in Volts).
The concept of voltage is one of the more difficult to grasp at this early stage in the development. Most people do not feel completely comfortable with this quantity until they have experienced a period of continuous exposure. Be assured that in time you will be as comfortable with this concept as with the more easily understood concept of current.
Consider a short length of copper wire. In this wire at room temperature with no external forces applied, there exists within the copper wire the random motion of free electrons created by the thermal energy that the electrons gain from the surrounding media. When an atom loses its free electron, it acquires a net positive charge, and is referred to as a positive ion. The free electron is then able to move about these positive ions, and leave the general area of the parent atom, while the positive ions only oscillate in a mean fixed position. This is why the electron is the charge carrier in the copper wire or in any other solid conductor of electricity. The electrons were once thought to flow from a positive (or unbalanced area consisting mostly positive ions) to a negative. This idea was conceived by an American scientist named Benjamin Franklin; it is called the conventional current. Since the electrons do move when placed in an unbalanced state (like in the basic circuit ), the current actually flows from a negative area to a positive area where they balance out the abundance of positive ions. These moving electrons can also do work, like moving a motor or activating an LED).
I usually follow the conventional flow of electricity! It is usually easier that way.
Current:
Current is the measure of electrons traveling in the certain part of the circuit. Current is measured in Amperes or Amps.
Resistance:
Resistance is the measure of impedance in a circuit. Resistance is measured in Ohms. A resistor would slow the travel of electrons form one part to the other.
Resistors:
Capacitance:
The equation that brings these together is V=I*R
V is voltage
I is current
R is resistance
A good analogy for these three is a garden hose. The voltage would be the nozzle that is high or low that pushes the water through the hose. The current would be the amount of water that passes a certain part in the hose. The resistance would be someone clamping the hose.
