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Basics of Electronic Components: Working Principles & Examples with PDF

Learn the basic electronic components – resistors, capacitors, transistors, and more. For beginners and developers. Explore the building blocks of electronics and get a free bonus PDF!
A collection of various electronic components and electronics displayed on a table.

Welcome to the ultimate guide to electronic components basics, where we dive deep into everything you need to know about these essential building blocks of electronic and electrical circuits.

So are you ready to explore the basics of electronic components? Whether you're an engineer, hobbyist, or simply curious about the inner workings of electronic devices, the ultimate guide to electronic components is your go-to resource for expanding your knowledge and enhancing your understanding of this fascinating field. This guide will equip you with the basics of fundamental electronic components. So, let's get started and unlock the secrets of electronic components basics together!

Basics of Electronic Components: Resistors, Capacitors, and Inductors

I know that talking about electronic components might sound a bit frightening, but fear not! I'll make this topic as clear and engaging as possible. From resistors to integrated circuits, capacitors to transistors, we'll explore the different types of electronic components, their functions, and how they work together to create and power the devices we rely on every day. You'll gain a clear understanding of the purpose each component serves and how they contribute to the overall functionality of electronic systems.

Why Understanding Working Principles Matters

Before we dive into the specifics of resistors, capacitors, transistors, and more, let's emphasize why comprehending the working principles is essential. The working principles define how each component functions within a circuit, and the behavior of electronic devices. Now, let's embark on a journey to unravel the working principles behind these electronic components and gain a deeper understanding of their roles in the world of electronic/electrical circuits.

Well, you might be wondering, what are the basics of electronic components? Whether you're an engineer, hobbyist, or simply curious about the inner workings of electronic devices, this ultimate guide is your go-to resource for expanding your knowledge.

Now comes the transistors, diodes, and integrated circuits, these are the active components, and are responsible for amplifying signals, controlling electronic flow, and making all those mind-boggling complex calculations.

But wait, did you see, I used active components and passive components? You may ask, what are active components? The electronic components that can modify, amplify, modulate, and switch the electrical signals are called active components. These components need an external power source for their operation. They are transistors, diodes, Integrated Circuits, etc.

Now, what are passive components? Passive components include resistors, capacitors, and inductors. These components can filter, modify, or store electrical signals without actively controlling or amplifying them. So basically, the electronic components that do not require any additional power source and can modify, filter, or store the electrical signals are called passive components.

We will discuss all these components in detail, along with their functions, symbols, units, formulae, and relevant laws if any, so hold tight for this electrifying journey, before that, here's a quick introduction to Basics of Electronic Components

But wait, there's more! We also have sensors actuators, and microcontrollers. They are like tiny spies (James Bond) that gather information from the outside world, think of temperature, light intensity, motion or sound, and even the touch, we will go through these as well, as they are the senses and brains of our electronic world.

Okay, so let's explore one by one:

Understanding Passive and Active Components

There are mainly two types of electronic components based on their operation:

  • Active components
  • Passive Components

Active Components: The components that are capable of modifying the electric signals are called Active components, they require external power to perform their operations, mainly these operations includes amplification, rectification, or modifying the given signal.

e.g. Transistor, Amplifier

Passive Components: In electronics, the components that do not require a power source to complete their operation are called passive components. these components are not capable of modifying the electrical signal, they cannot amplify, modify, or generate the electrical signals

e.g. Resistor, Capacitor, Inductor

Basics of Resistors

A bunch of fixed carbon film resistors
fixed resistors

Resistors are fundamental components that limit the speed of electron flow, i.e., current. Think of them as speed breakers; similar to how speed breakers encourage us to limit the speed while driving, resistors function the same for controlling the flow of electric current.

Types of resistors:

there are two main types of resistors

Fixed Resistors:

The resistance value is fixed on these resistors and can't be changed. Examples of these resistors are:

  • Carbon Film Resistor
  • Metal Film Resistor
  • Wire wound Resistor
  • Thick Film Resistor

Variable Resistors:

The resistors whose value i.e. resistance can be changed or varied are called variable resistors. E.g., potentiometers, presets, etc.

Resistor colour code

For fixed resistors, their value can be calculated by looking at their colors. The stripes that you can see in the above image have special meanings; refer to the following table to see their values.

Generally, these resistors have 3 or 4 bands, but they can also be up to 6 bands, but the logic to calculate their values is similar.

Brown110 Ω±1%
Red2100 Ω±2%
Orange31 KΩ
Yellow410 KΩ
Green5100 Ω
Blue61 MΩ
Gold0.1 Ω±5%
Silver0.01 Ω±10%

For calculating 3 band resistor value:

1st band: it signifies 1st digit

2nd band: it signifies the 2nd digit

3rd band: this band signifies a multiplier

For calculating 4 band resistor value:

1st band: it signifies 1st digit

2nd band: it signifies the 2nd digit

3rd band: this band signifies a multiplier

4th band: this band signifies tolerance

For 5, 6 band resistors:

The last 2 bands have the same meaning but the first 3 or 4 bands are the significant digits in the case of 5 and 6-band resistors respectively


Photo of Resistor with 5 striped bands on its body
Resistor with colour code

Here in this example

1st three bands refer to the 1st three significant digits the 4th band is the multiplier, the last one is the tolerance

let's calculate:

put the 1st 3 digits as it is: i.e. 426, next is a multiplier i.e. 10^3, last one is tolerance i.e. ±10%

putting it all together: 426KΩ ± 10%

Some important formulae about resistors:

Ohm’s law:

It states that the current flowing through a conductor is directly proportional to the voltage across its two ends. Read more on Ohm’s law

Capacitors Unveiled

A capacitor is an electronic device that stores electric energy in the form of electrical charge accumulated on their plates. When a capacitor is connected to a power source, it gets charged as the charges accumulate on its plates. Soon the power source is disconnected, the charges on the plate are released, and hence the capacitor acts like a mini battery.

But hey, did you see, I said a capacitor stores the charges in its plates, so let me show you the internals of a capacitor.

See these grey parts below, these are called the plates and the blackish material inside is called a dielectric. The plates of the capacitor are conducting, but the dielectric material is insulating or non-conducting. The dielectric material prevents the flow of electrons, but it allows the electric field to exist.

The capacitor has a property called capacitance, capacitance is defined as the ratio of electric charge (Q) stored in the capacitor to the voltage (V) applied to it and its unit is farads(F).

C = Q / V

Construction of capacitor
Construction of capacitor

Types of capacitors

Following are the types of capacitors along with their dielectric material, capacitance, voltage ratings, and important characteristics.

  1. Ceramic Capacitor

    Dielectric Material: Ceramic
    Capacitance: Typically ranges from picofarads (pF) to microfarads (uF).
    Voltage Rating: Can range from a few volts to hundreds of volts.
    Characteristics: Commonly used for high-frequency applications, compact size, and low cost.
  2. Electrolytic Capacitor:

    Dielectric Material: Oxide layer
    Capacitance: Higher values, often in microfarads (uF) to farads (F).
    Voltage Rating: Usually for higher voltage applications.
    Characteristics: Polarized (must be connected with the correct polarity), higher capacitance values, used for power supply filtering.
  3. Tantalum Capacitor:

    Dielectric Material: Tantalum Oxide
    Capacitance: Typically in the range of microfarads (uF) to farads (F).
    Voltage Rating: Suitable for higher voltage applications.
    Characteristics: Polarized, high stability, used in applications where reliability is critical.
  4. Film Capacitor:

    Dielectric Material: Various types, including polyester (Mylar), polypropylene, and polyethylene.
    Capacitance: Ranges from picofarads (pF) to microfarads (uF).
    Voltage Rating: Varies, but can handle moderate voltage levels.
    Characteristics: Non-polarized, good for precision applications, and available in various materials like polyester, polypropylene, and more.
  5. Variable Capacitor:

    Dielectric Material: Conductive polymer
    Capacitance: Adjustable, often used in tuning circuits.
    Voltage Rating: Varies, typically low.
    Characteristics: Designed to vary capacitance for tuning purposes in radios and other devices.
  6. Supercapacitor:

    Dielectric Material: Electrochemical double layer.
    Capacitance: Typically in the range of farads (F) or even hundreds of farads.
    Voltage Rating: Can handle moderate voltages.
    Characteristics: Known for high capacitance, rapid charge/discharge, and used in applications requiring quick energy storage and release.

Applications of capacitors:

Capacitors are like tiny energy storage tanks in electronics. They have three main jobs:

  1. Filter Noise: They clean up electrical signals, convert the fluctuating DC to smooth DC.
  2. Store Energy: They save and release electrical energy when needed, like a battery.
  3. Start Motors: In things like fans or toy cars, capacitors give the initial push to make them start spinning. You might have seen your fans, those big cylinders-like guys.
  4. Block Static: They keep your computer chips safe from sudden electricity spikes, like a shield.
  5. Signal Boost: In radios and antennas, capacitors help to make weak signals stronger, like using a magnifying glass to see things better.

Diodes Explained

Diodes are semiconductor devices that allow the flow of electric current in only one direction and block the other. It is a two-terminal device made by joining P-Type and N-Type semiconductors.

Now, you may ask what are these semiconductors? What are P-type and N-type semiconductors? A semiconductor, as its name suggests, is neither a conductor nor an insulator, its conductivity lies between them, meaning that, a semiconductor device acts as a conductor when it meets certain conditions otherwise it acts as an insulator.

Let me break it down even further, a semiconductor, when it meets certain conditions, allows the electric current to flow and blocks it otherwise.

The electrons in the outermost orbit of the semiconductor are responsible for this behaviour, the valence electrons or the valency of these semiconductor atoms, the construction is out of scope, read more about diodes

Now P-type and N-type semiconductors are nothing but when p-type impurities are added to these semiconductors they form a p-type semiconductor, similarly, when an n-type impurity is added to it, they form an n-type semiconductor

Construction of diode
Construction of diode

Types and applications of diodes

There are various types of diodes, each designed for specific applications. Here's an overview of some common types of diodes:

  1. PN Junction Diode: The standard diode is composed of P-N semiconductor materials. Allows current to flow in one direction while blocking it in the other.
  2. Light Emitting Diode (LED): Emits light when current flows through it. Widely used in displays, indicators, and lighting applications.
  3. Zener Diode: Designed for voltage regulation and voltage reference applications. Provides a constant voltage across its terminals when operated in the reverse breakdown region.
  4. Schottky Diode: Known for its fast switching capabilities. Used in high-frequency and high-speed applications. Has a lower forward voltage drop compared to standard diodes.
  5. Varactor Diode (Varicap Diode): Used in tuning circuits, such as in radio receivers, to change the capacitance and tune specific frequencies.
  6. Avalanche Diode: Operates in the avalanche breakdown region. Used in avalanche photodiodes for detecting light.

Transistors: Building Blocks of Modern Electronics

Transistors are fundamental electronic components that play a crucial role in amplifying and controlling electrical signals in our electronic circuits. They are often described as the "building blocks" of modern electronics.

Without transistors, it would be challenging to build the complex electronic devices and systems that have become an integral part of our daily lives.

In other words, transistors act like electronic switches and signal boosters that allow us to create everything from simple on-off switches to powerful computers. yes, you saw it right, the computer CPUs that we use have millions of transistors in them.

Photo of a transistor

Here's an overview of transistors:

  1. Bipolar Junction Transistor (BJT): BJTs are three-layer semiconductor devices (N-P-N or P-N-P). They amplify current and can be used as switches. Commonly used in analog applications and amplifiers.
  2. Field-Effect Transistor (FET): FETs control current flow using an electric field. They are classified into MOSFETs (Metal-Oxide-Semiconductor FET) and JFETs (Junction FET). MOSFETs are commonly used in digital and power applications, while JFETs are used in low-frequency applications.
  3. MOSFET (Metal-Oxide-Semiconductor FET): MOSFETs are widely used in digital and power electronics. They have low power consumption, making them suitable for integrated circuits (ICs).

Key Functions and Significance:

  1. Amplification: Transistors amplify weak electrical signals, making them stronger. This is essential in audio amplifiers, radios, and other signal-processing applications.
  2. Switching: Transistors can act as electronic switches, controlling the flow of electrical current. In digital circuits, they enable us the represent binary logic i.e. 0s and 1s.
  3. Signal Modulation: Transistors also play a vital role in amplitude modulation (AM) and frequency modulation (FM) in communication systems.
  4. Voltage Regulation: They help regulate voltage levels in power supplies, ensuring stable and precise output voltages.

Integrated Circuits Overview

Integrated Circuits often called ICs are miniature electronic circuits made up of semiconductor materials, mostly silicon. You might have seen those black squares/rectangles with legs.

These circuits house thousands, millions, or even billions of electronic components, including transistors, resistors, capacitors, and more, all on a single chip.

The components are interconnected to perform various functions, from processing data to controlling electrical signals.

Photo of Integrated Circuits
Integrated Circuits

Types of Integrated Circuits

  1. Analog ICs: Handle continuous signals for tasks like amplification and voltage regulation.
  2. Digital ICs: Process discrete binary signals (0s and 1s) for computing and memory functions.
  3. Mixed-Signal ICs: Combine analog and digital circuitry, used in devices like smartphones.
  4. RF ICs: Specialized for radio-frequency applications, like amplifying and processing wireless signals.
  5. Memory ICs: Store and retrieve data, from computer DRAM to flash memory in USB drives.
  6. Power Management ICs (PMICs): Regulate voltage and manage power in electronic devices.
  7. Communication ICs: Enable data transmission, including Ethernet controllers and wireless communication.

Microcontrollers and Their Applications

These are small, embedded computers on a chip, used to control devices and processes in appliances, automobiles, and industrial systems. They are like the brains of the system.

Photo of ESP8266, ESP32 Microcontrollers, HC05 and Nordic Semiconductors’ development board
Photo of ESP8266, ESP32 Microcontrollers, HC05 and Nordic Semiconductors’ development board


  • 8051 microcontrollers: This intel-developed family of microcontrollers is widely used. these are 8-bit microcontrollers suitable for small projects, robotics, and simple applications.
  • Arduino: well Arduino is not a microcontroller but for its wide use and simplicity I’m adding here, that Arduino boards are development boards based on the ATMega328P microcontroller, they make the development and prototyping of embedded systems a lot easier, and they have Arduino IDE, framework and support for several libraries.
  • Wireless microcontrollers: ESP32, ESP8266, and Nordic Semiconductor MCUs are a few to list, they provide wireless connectivity, and some offer Wi-Fi, Bluetooth, or other networking protocols and hence are suitable for IoT-based applications.

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Conclusion and Future Insights

Whether you're a seasoned developer or a curious beginner, understanding the diverse range of electronic components and technologies is crucial for those who seek to innovate. From fundamental concepts like active components to the intricate workings of capacitors and diodes, the electronic landscape is vast and rich with possibilities. These basic electronic components are the building blocks of every electronic or electrical circuit.

As you embark into more advanced territories, the likes of transistors and integrated circuits (ICs) take center stage, enabling the incredible devices and systems we rely on daily. Each of these components and technologies plays a unique role, from amplifying signals to controlling power and even facilitating wireless communication.

It's within this intricate framework that microcontrollers find their place, offering the power to control, automate, and create. Whether you're exploring Arduino for creative projects or delving into the world of 8051 microcontrollers for practical applications, these tiny but mighty devices open the door to endless possibilities.

Ultimately, electronics is a journey that allows creators like me 😜 to bring their visions to life. With the right knowledge and tools, the possibilities are limitless, from designing smart homes to crafting interactive art installations. It's a world where curiosity and innovation unite to shape the technology of tomorrow.

So, whether you're a developer, a hobbyist, or a curious explorer, the electronic realm is yours to explore, experiment with, and innovate upon.

And that's a wrap on the basics of electronic components. In the future, we'll dive deeper into the fascinating world of electronic terminologies. Stay tuned for more electrifying insights. Signing off, Krypton.

Frequently Asked Questions

  • What are the types of electronic components?

    There are two types of electronic components based on their ability to control the flow of electric current/signals. The Active components and Passive components.

  • What are the basic components in electronics?

    In electronics, the basic components include resistors, capacitors, inductors, transistors, diodes, and relays. These components serve as the building blocks of electronic circuits.

  • How do resistors limit the speed of electron flow?

    Resistors are made up of less conductive materials, they are poor conductors of electricity and hence when placed in an electrical circuit, the electrons pass slowly and their speed is limited

  • What is the role of a diode in electronics?

    There are various types of diodes, however a common P-N Junction diode is used to allow the electric current to flow from only one direction, acting like a switch

  • What is a semiconductor?

    A semiconductor is a material whose conductivity lies between a conductor and a resistor, these material act like a conductor when some amount of heat or energy is given to them otherwise they behave like an insulator.

  • What is a transistor used for?

    A transistor is a vital electronic component that amplifies signals and controls the flow of electric current. It's like the traffic cop in circuits, directing currents to make devices work efficiently. Whether in radios, computers, or other gadgets, transistors play a crucial role in enhancing and managing electrical signals.

  • What is the purpose of a capacitor?

    A capacitor stores and releases electrical energy, smoothing out signals and providing a quick energy boost. It acts like a mini battery, crucial for stable power in electronic devices.

  • What might be some components of an electronic system?

    Components of an electronic system include resistors (regulate electric current), capacitors (store and release energy), diodes (control current direction), transistors (amplify and control signals), integrated circuits (ICs, house multiple components on a chip), and microcontrollers (act as the system's brain, controlling devices and processes).

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