Electronics for Beginners

I’ve been interested in electronics for some time now but I’ve never done anything to cultivate that interest or increase my knowledge. That changes today.

Come along with me as I chronicle my journey, from complete beginner to…something more than that. I’m calling this series Electronics for Beginners and I hope it can be a resource for others that want to learn about electronics.

What I’m sharing in this series is essentially my notebook from the basic studying that I have done to this point. I’ll publish a list of resources at the end of this series.

Words that are in bold italics are important words and worth remembering.

What is Electricity?

Electricity. Electronics. Both of these words are rooted in the word electron. Together with proton and neutrons, electrons form atoms, which make up everything around us in the world. Protons and electrons contain an electrical property known as charge. Protons are positively charged and electrons are negatively charged; similar charges repel each other and opposite charges are attracted to each other.

Current is simply the flow of electrons. There are two types of current that you’ll typically here people talk about: alternating current (AC) and direct current (DC).

Alternating current gets it name from the fact that the flow of electrons is constantly alternating, many times per second. The flow is constantly reversing. Direct current, on the other hand, flows in only one direction.

AC is what you get from the wall outlets in your house. It’s generally used for large appliances. DC is what you use for things like the batters in your phone or your laptop. When you plug your phone charger into the wall outlet and then into your phone, the charger is converting the AC into DC so that the battery can use it to store energy.

Current is often represented by the symbol I and is measured in amperes or amps, which is often represented by the symbol A.

How Does Current Flow?

Current flows from negative points to positive points. In order for the current to flow from one point to the other, a circuit must be completed.

To help think about this, let’s imagine a battery with a negative terminal and a positive terminal. We’ve all seen a battery with a minus sign (- the negative terminal) and a plus sign (+ the positive terminal). Now let’s imagine that one wire is protruding from the negative terminal and connects to a light bulb, and another wire is protruding from the positive terminal, but it doesn’t quit reach the light bulb. You could call this an open circuit. The current will not flow and the light will not turn on. Even though there is a wire connecting the negative terminal of the battery to the light bulb, the other wire that connects the bulb to the positive terminal and completes the circuit is not connected.

Now, if we connect the wire from the positive terminal to the light bulb…voila! A closed circuit — the light is now on and we have built a simple circuit!

We’ve connected the negative and positive terminals via wires that are connected to a light bulb. Pretty cool.

Now, remember that we said electricity is simply the flow of electrons? There are a few things that impact just how that flow flows. I’m going to lay out some terms that we’ll need to know and then I will share an example that helps me to think about how this all works.

Voltage is the pressure of electrons flowing through a wire, or whatever conductive material is carrying the electrons. Voltage is often represented by the symbol V. If current is the flow of electrons, then amps (how you measure current) represents the rate of that flow.

In order to regulate the flow of current, we need something called resistance, which is often represented by the symbol R, and is measured in Ohms, which is often represented by the symbol Ω (omega).

Got that? Let’s try an example.

Imagine a water tower that supplies water to your city. There’s a large pipe extending down from the bottom of the tower and into the city’s water supply. The tower is full of water. In our example, the water in the tower is our current. The water pressure that is generated by gravity pulling the water down through the opening in the pipe is the voltage. The size of the pipe is resistance. If we change the pipe to one with a smaller opening, the flow rate of the water, or the amperage (measure of current), will decrease even though the voltage (amount of pressure being applied to push the current) has not changed. By increasing the resistance, we require more electrons to overcome that resistance resulting in less current flowing through the circuit.

This represents my full knowledge of electronics at this point. Like I said, I’m a complete beginner. I’m excited to learn more and will continue to share as I gain more knowledge. I hope this series of posts on electronics for beginners proves valuable for other out there that want to being learning about electronics.