Basic Electronic Components in Circuits

As you progress, you’ll start working on projects or circuits that incorporate a variety of electronic components.

To gain more confidence building your circuit, familiarize yourself first with the fundamentals. Start learning the basic components that are commonly used in electronics.

Some of them have straightforward behaviors that are easy to understand and some are a little bit challenging. But eventually, you should be able to combine these components to create more complex and functional circuits in the future.

Resistors

Let’s begin with the resistor. You’re probably already familiar with this one, as you often see this in any circuit or device.

The main function of a resistor is to slow down the flow of electric current in a circuit. They do this by providing resistance. We measure this resistance in ohms (Ω).

Potentiometers (Pots)

These are known as potentiometers, which are a type of resistor with three connection points. It’s a variable resistor, which means you can set its resistance to a certain value. With regards to its three terminals, the outer two are fixed resistors, and the middle one is the adjustable tap or wiper.

Depending on how you configure it in a circuit, you can use it to change the flow of current or divide a voltage.

Light-Dependent Resistors (LDR)

Light Dependent Resistor (LDR), also called a photoresistor, is a special kind of resistor that reacts to light intensity. When it’s bright, the LDR’s resistance goes down, and when it’s dark, the resistance goes up. It is what makes an automatic night light circuit function.

Capacitors

The main purpose of a capacitor is to store and release electrical charge. I often use them for voltage filtering in simple circuit projects. They help maintain a steady and filtered DC voltage; they are good at reducing noise and voltage fluctuations.

Now it’s important to note that a capacitor may have a specific orientation; polarized or non-polarized.

A polarized capacitor has a specific polarity, meaning it has a positive and negative terminal and must be connected in a certain way in a circuit. A non-polarized capacitor, on the other hand, doesn’t have a specific polarity. You can connect it in either way in a circuit.

Switches

It’s a simple component but you’ll need it to control the power supply, change settings, or enable/disable certain functions. The primary role of a switch is to either open or close an electrical circuit.

Some circuit designs require no switch, but when building projects, I always include a switch to control the power supply. This is not just to turn ON or OFF the device but it’s also for me to quickly disconnect power in case something went wrong with my circuit design.

Different Switch Symbols

Diodes

A diode is a semiconductor device with two terminals, an anode (positive) and a cathode (negative). Its main function is to allow current to flow in one direction only. With that said, they are commonly used to convert AC to DC in power supply circuits.

Note that there are several types of diodes, and each is specially designed for specific applications and functionalities.

Light Emitting Diodes (LEDs)

LED is a type of diode used for emitting light. I mainly use LEDs to provide visual output or as indicator lights for some of my projects.

But of course, you aren’t limited to it. You can use them to build cool lighting projects like LED chasers, LED matrix displays, an LED cube, traffic lights, etc.

Zener Diode

It operates in the reverse-bias direction and maintains a nearly constant voltage across its terminals. You can use it for voltage regulation and protection against voltage spikes.

I once used a Zener diode to regulate the output voltage of my 5-volt power supply circuit. And it maintained a stable output voltage despite the fluctuations in input voltage.

Inductors

An inductor stores energy in a magnetic field when current flows through it. It is typically constructed as wire coils, and the number of turns, the core material, and the geometry influence its inductance.

You can see them in various electronic circuits or devices to step up or down voltage levels, such as DC-DC converters.

Transistors

Transistors can be a little challenging concept for beginners because they are inherently complex and involve operational analysis.

However, you are highly likely to encounter transistors when learning electronics because, in practical applications, they can act as amplifiers, switches, and signal modulators.

I won’t go over it in detail but if you want to learn more about it, it’s better to break down the key concepts into simpler terms and focus on practical applications.

Integrated Circuits

Integrated Circuits, or ICs for short, are like tiny electronic brains. They’re made up of many tiny electronic components, such as transistors and resistors, all packed into a small chip.

As you progress and deepen your understanding of electronics, you will undoubtedly encounter integrated circuits (ICs) in various forms.

For example, after learning about individual electronic components like resistors, capacitors, and transistors, you’ll probably start working with simple ICs such as operational amplifiers (op-amps), 555 timers, voltage regulators, and basic logic gates.

You often see them represented as rectangles. Below are some examples of integrated circuits (ICs) and their symbols.

Connectors and Wires

Well, it’s not technically an electronic component, but you’ll need it to facilitate the physical connection of components in a circuit. Also, you need jumper wires to connect components on the breadboard.

If you’re building electronic projects or devices, you might use connectors to attach a sensor to a microcontroller, a display to a mainboard, or various modules to a development board. 

DC power source

Lastly, a circuit needs an energy source, either coming from a battery or a power supply. The power source energizes these components within the circuit, which enables them to perform their intended functions. Without a power source, your circuit would not operate or function.