## Protons, Neutrons, and Electrons

Everything is made up of atoms. Atoms are made up of protons, electrons, and neutrons. The nucleus of the atom contains neutrons which have a neutral charge and protons which have a positive charge. Electrons orbit the nucleus and have a negative charge.

If you have the same amount of protons as electrons, you’d have a neutral charge. If the atom loses an electron, you’d have a positive charge. If the atom has more electrons, the atom would be negatively charged. Electrons can jump from one negatively charged object to a positively charged one and will balance the charge. The energy used when the electrons move is the voltage.

## Alternating current

#### What is Alternating Current?

Alternating current, (AC) is the most common form of electricity. AC became the standard due to the ease of distributing power over a long distance. With AC, a simple transformer outside your house steps the voltage down from the power company supply to a usable voltage in your home. Since it’s made up of no moving parts and some coils of wire, it’s a lot less expensive than using DC power as the standard delivery method.

## Direct current

#### What is Direct Current?

In a DC (direct current) circuit, all the electrons hop from electron to electron in a single direction, hence the name, direct current. Since electrons only flow in one direction, electrical polarity matters, so you’ll need to place each wire exactly how it’s depicted on a wiring diagram.

## Polarity

Polarity is the direction of current flow in a circuit from the two poles, positive and negative. You require two points of differential charge for any electron movement to take place.

In an AC circuit, each pole alternates between positive and negative 60 times per second. You can see from the image of the AC sine wave, that the change in polarity of AC does not happen instantly, although close to and 60 times per second (Hertz).

## Electrical circuit components

A most basic electrical circuit will have three components

• A source of energy. It could be a battery or an electrical outlet in the wall
• A load. A load does useful work. A load could be a light bulb or a motor

While not entirely needed, most circuits will include a switch. A switch will stop the flow of electricity through the conductor to the load.

As you can see, with an open switch, power cannot get past the switch to turn on the lights.

With the switch in the closed position, power is allowed to flow through the circuit and turn the lights on.

## Voltage

Earlier we covered electrons moving from atom to atom. Metallic bonding forms copper. The bond is made when many metal atoms share their collected valence electrons. The valence electrons are not attached to any specific atom, so they move around freely.

Now to get these electrons moving in one direction and being of more use, they just need a push. This is by applying an electromotive force (emf), also known as voltage.

## Current (amps)

Sticking with the water analogies, amperes, or amps for short, is the amount of water flowing through the hose. The higher the pressure (voltage), the more water flows (amps) out of the hose. In Ohm’s Law, amperage is represented by “I.”

## Resistance

Almost all material has some form of resistance to electrical flow. Without resistance, you’d have no way for a circuit to do useful work. Like stated earlier, conductors are materials that allow current to flow, and insulators don’t. Conductors have little resistance.

Resistance in a circuit is measured in Ohms or the Greek letter “Ω.” Current flowing through an electric range or toaster causes the elements to generate heat to cook your food by using resistance. In Ohm’s Law, resistance is represented by “R.”

## Voltage, current, and resistance summary

To quickly sum up voltage, current, and resistance.

Voltage is the driving pressure which is the high and low potential in the water tower below.

Current (amperes or amps) is the resulting flow which is the water flowing through the pipe in the water tower below.

Resistance completes useful work. The wheel spinning in the water tower below.

## Series Circuits

series

noun

1. a number of things, events, or people of a similar kind or related coming one after another.

So given the above definition, a series circuit is when there’s only a single path for current to flow. Any break in the wiring or a faulty load will stop current throughout the entire series circuit.

A load is anything in the circuit that does useful work, like the lightbulb in the example below. The inexpensive and/or old Christmas lights have this downfall. When a single bulb burns out, the entire string of lights goes out.