Basic Electronics

A voltage divider is a circuit that creates a smaller voltage from an input voltage by using two resistors. You’ll see it in both simple and advanced circuits all the time. Here’s the basic setup:

It is useful for example for reading sensors like thermistors and photoresistors since it converts an unknown resistance into a voltage. Or to reduce the volume of an audio signal via a potentiometer.

You can find the output voltage by inserting the resistor values and the input voltage into the following formula:

Or you can use the calculator a little bit further down on this page.

Once you know how it works, it’s much easier to see how circuits work. And it will let you calculate voltages at many different points in a circuit – which is often needed to understand it.

Are you struggling to understand circuits and see how currents flow?

I wrote this based on an interaction I had with Gary.

And maybe it can help you.

I was developing some new material for a course.

And I used Gary as my test subject. He’s an adult British gentleman with no electronics background whatsoever.

He told me that if he could understand this, then anyone could.

“How to combine components to get a specific function?”

Many people ask me this.

But that’s like if you want to learn the piano and ask:

“How to combine notes to play a specific song?”

What you need to do to learn to play the piano is to practice playing the piano.

Electric current is what you get when electric charge moves around a circuit. It’s pretty simple when you finally get it. But there are some common pitfalls that can give you the wrong idea when learning.

And if you don’t know what current is and how it works, it’s a huge source of confusion when learning electronics.

My goal is that after reading this article, you’ll understand what current is. And you’ll understand that a resistor must have the same amount of current going into it as going out from it.

The RC delay element is a way to create a time delay in your circuit by connecting a resistor and a capacitor. It’s super simple. And very useful.

The ‘R’ is a resistor, and the ‘C’ is a capacitor. That’s where the ‘RC’ comes from. And here’s how you connect the two:

A circuit simulator is a tool for “seeing” what a circuit does. In comparison to mechanical machines such as a bicycle and a lever, electronics cannot be easily inspected by the naked eye.

When you look at a bicycle you can observe it and see that stepping on the pedals makes a chain turn, and that this chain moves the bicycle wheels.

In contrast, if you open up an audio amplifier, it will be really hard to tell what it does if you don’t have previous experience in designing and building electronic circuits.

The following is from the book 5 elements of effective thinking by Burger and Starbird. A great book that shows you how to think better:

Kirchhoffs law of current and voltage are two laws that are really useful when you are working with circuits.

Knowing them will make it much easier to understand circuit diagrams, design electronics, repair electronics and everything in between.

Though they might sound complicated (*), they’re not.

After you’ve learned them, it’s not really something you use – it’s something you KNOW. And it makes looking at and understanding circuit diagrams much easier.

A short circuit is a connection that was not meant to be there. For example, if you accidentally connect the plus to the minus of a battery, you have a short circuit between the plus and minus of the battery. Which is not good.

You can use it as a verb as well:

“I accidentally shorted the battery and it exploded!”

(Yes, some batteries can really explode if you short-circuit them.)

This is a very important concept to understand because it’s used a lot in “electronics language”.

Current, voltage and resistance are three important concepts in electronics. I didn’t have a clue about these things when I started out. But I could still build fun things, by following the circuit diagrams I found. I just didn’t know what was going on.

When I started learning about basic electricity in school, many pieces started to fall into place. I started understanding some of the explanations from the circuit diagrams I built.

I like to focus on the practical parts of electronics. But learning some theory as you progress is also really useful. So in today’s article you will learn the basics of current, voltage and resistance.