Basic Electronic Components Used in Circuits

Some basic electronic components drawn as cartoons

I learned about the basic electronic components by going to the library and reading books.

I was just starting out.

And I felt like a lot of the books explained everything in a difficult way.

In this article, I will give you a simple overview, with an explanation of the basic electronic components – what they are and what they do.

The Most Common Basic Electronic Components

These are the most common components:

  • Resistors
  • Capacitors
  • LEDs
  • Transistors
  • Inductors
  • Integrated Circuits


A Through-Hole Resistor
Find the resistor symbol in the schematic symbols overview.

I didn’t understand the resistor in the beginning.

It didn’t seem to do anything! It was just there, consuming power. But with time, I learned that the resistor is actually extremely useful.

You’ll see resistors everywhere. And as the name suggests, they resist the current.

But you are probably wondering: What do I use it for?

You use the resistor to control the voltages and the currents in your circuit.

Some basic electronics components: LED in series with a battery and a resistor


By using Ohm’s law.

Let’s say you have a 9V battery and you want to turn on a Light-Emitting Diode (LED).

If you connect the battery directly to the LED, LOTS of current will flow through the LED!

Much more than the LED can handle. So the LED will become very hot and burn out after a short amount of time.

But – if you put a resistor in series with the LED, you can control how much current is going through the LED.

In this case, we call it a current-limiting resistor.

It’s also possible to find adjustable/variable resistors. This is called a potentiometer and it has three pins.


Electrolytic capacitor
Find the capacitor symbol in the schematic symbols overview.

You can think of a capacitor as a battery with very low capacity.

You can charge and discharge it just like a battery.

The capacitor is often used to introduce a time-delay in a circuit.

For example to blink a light.

It’s commonly used for removing noise, or making the supply voltage of a circuit more stable.

Read more about the capacitor in this article: How Does A Capacitor Work?

There are many capacitor types. Most commonly, we divide them into polarized and non-polarized capacitors.

Light Emitting Diode (LED)

Find the LED symbol in the schematic symbols overview.

A Light Emitting Diode – or LED for short – is a component that can give light.

We use LEDs to give a visual feedback from our circuit.

For example to show that the circuit has power. But, you can also used them to make cool light-show circuits.

You see these components everywhere:

In your laptop, on your mobile phone, on your camera, in your car +++

And you can find many different types of LEDs.

A very common circuit to build as a beginner is the blinking light circuit.


Two transistors in a circuit
Find the transistor symbol in the schematic symbols overview.

This is probably the hardest of the basic electronic components to understand.

But don’t worry, it’s not that hard.

A simple way is to look at the transistor as a switch controlled by an electrical signal.

If you put about 0.7 volts between the base and the emitter, you turn it on.

Note that this is true for NPN transistors. There are also other types, but worry about these later.

But, instead of having just two states (ON or OFF), it can also be “a bit on” by controlling the current that goes through its base.

A bit of current on the base produces a current of maybe 100 times more (depending on the transistor) through the Collector and Emitter. We can use this effect to build amplifiers.

Explanation of how a transistor works

I’ve previously made a video on how transistors work.


A homemade inductor
Find the inductor symbol in the schematic symbols overview.

Inductors are a bit weird.

It’s just a coil of wire – and you can make one yourself by making some loops out of a wire.

Sometimes they’re wound around a metal core of some sort.

They are often used to make radio oscillators, more efficient power supplies, and filters.

It’s not that often that I used one actually, but in my article What is an inductor? you can see how it works with some nice animations.

Integrated Circuit

Integrated circuit - one of the basic electronic components
Find the integrated circuit symbol in the schematic symbols overview.

An Integrated Circuit (IC) consists of many basic electronic components.

It’s nothing mysterious or magical.

It’s just an electronic circuit that has been shrunk to fit inside a chip.

It could be an amplifier, it could be a microprocessor, it could be a USB to serial converter… It could be anything!

To figure out what a specific IC does, you can read its datasheet.

What to do next?

Now, you know a bit about the basic electronic components.

But don’t just read about it – take action and start building electronics:

Ohmify is an online academy for electronics. Learn to build your ideas with electronics, even if you have no experience from before. It includes a community forum where you can ask questions about what you are learning or if you’re stuck on your on project.

Click here to learn more about Ohmify.

Do you understand the basic electronic components? Leave your comment or questions in the comment field below!

More Electronic Components Tutorials