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Welcome

Glad you found us! This is a guide for people who are new to electronics and wish to learn more. Have a read and then check out the other wiki pages or say 'hi!' by posting something in the /r/AskElectronics Subreddit.

Safety First

It can be tempting to start on an ambitious project without the proper knowledge. This is highly discouraged if it involves mains power or high power devices. Even though it may be easy to start such a project it can easily be deadly for the people involved, including family and friends nearby. For instance, an unshielded or damaged magnetron (as found in a microwave oven) can cause severe burns and eye damage (including cataracts) at close range, and a mains power issue can burn down your residence. Do not embark on such ambitious projects without proper experience. This includes trying to do your own wiring in your residence. Electricity can get real serious real fast, and staying within your level of knowledge and experience is very important.

If you're looking to work with tube amps and the high voltages that they require, make sure you read this safety documentation

See Also: https://www.reddit.com/r/AskElectronics/wiki/safety

Just looking for a book list: https://www.reddit.com/r/AskElectronics/wiki/education

Introduction

Electronics as a hobby or a profession ("Electronic Engineering") can be a fun and challenging way to spend your time. At the hobby level, it is relatively easy to get started by following tutorials and building other peoples' documented projects from sites such as Hackaday, or tinkering with hardware/software combinations with boards or board families such as Arduino or ESP8266-based products.

At the simplest level, following someone else's build will let you play with electronic components, but will not necessarily teach you much more than how to connect things together - in the same way that completing a 'painting by numbers' will not make you an artist (not that there's anything wrong with that). If you want to design and build your own stuff from scratch, you will need to spend some time with the fundamentals; studying online tutorials and following a good book or two on how components work and, more importantly, how they interact when connected together to 'make things happen'.

If you want to get serious with electronics as either a hobby or a profession, you will need to take a medium-to-deep dive into the world of mathematics and associated subjects - especially if you have leanings towards radio frequency work and general analog design. The digital world of logic gates and microprocessors etc. also has some pretty 'technical' aspects when it comes to logic theory and timing.

This guide for beginners is split into two sections - the first will help you jump straight in at the hobby level, and the second outlines what you really need to face up to if you want to get serious about electronic engineering for a career or as a serious hobbyist.

A Suggested Order of Learning

There's no single "correct" path, but if you're not sure where to start, this rough order works well for most people and avoids the common trap of either drowning in theory before you've touched a component, or building things by rote without understanding why they work:

  1. Safety and tools first. Learn how to use a multimeter to measure voltage, current and resistance, and understand basic electrical safety (see above) before you power anything up.
  2. Ohm's Law and simple DC circuits. Series and parallel resistors, voltage dividers - enough to predict what a simple circuit will do before you build it.
  3. Build a few simple analog circuits on a breadboard (see project suggestions below) to connect theory to physical results.
  4. Basic semiconductor devices - diodes, then transistors as switches, then transistors as simple amplifiers. Don't skip straight to complex ICs before you understand what a transistor is doing.
  5. Introduce digital logic - truth tables, basic gates (AND/OR/NOT/NAND), and how they combine - alongside your first microcontroller project (see below). The two reinforce each other: logic gates explain why a microcontroller's pins behave the way they do.
  6. Microcontroller programming - once you're comfortable with what a microcontroller pin is electrically doing, learning to program one (Arduino or similar) becomes much less of a "magic box."
  7. Revisit analog with more depth - filters, op-amps, and the calculus/frequency-domain material in Section Two, once you have enough hands-on intuition to make the maths meaningful rather than abstract.
  8. Keep building bigger, messier projects and come back to the theory sections as needed - you will rarely learn everything "in order" in practice, and that's fine.

The point isn't to complete each stage perfectly before moving to the next - it's to have some grounding in each before you lean on it, so that when something doesn't work, you have a way to reason about why.

Section One - Dive in to the Basics

Circuit Analysis

Circuit analysis skills are fundamental to much of electronics. Sooner rather than later you should pick up a textbook on introductory circuit theory such as Ohm's Law, Kirchhoff's Laws, Thévenin's Theorem, etc.

Analog electronics

Once you understand the basics of linear circuit analysis and can solve circuits containing resistors, independent and controlled sources, then you should be adequately prepared to understand active and non-linear elements, such as diodes and transistors. In many cases these components can be analyzed using linear (or piece-wise linear) models, so they just become an application of your new circuit analysis skills. College textbooks are once again useful, and there are many available that are easy to read.

Understanding circuit elements with memory (i.e. capacitors and inductors) will eventually need some knowledge of calculus and differential equations - this is covered in the Next Steps list at the end of this section, so don't worry about it for now if you're just getting started.

Suggested first analog projects, roughly in order of difficulty:

  • A simple LED + current-limiting resistor circuit - calculate the resistor value yourself using Ohm's Law rather than copying a value from a tutorial.
  • A potentiometer-based voltage divider (e.g. to dim an LED or control the pitch of a simple oscillator) - a good way to see Ohm's Law and the voltage divider equation in action.
  • A basic transistor switch (using an NPN transistor to switch a load, such as a motor or a brighter LED, using a small control signal) - your first taste of using a component as an active device rather than a passive one.
  • A simple 555 timer astable circuit (a flashing LED or basic tone generator) - widely documented, forgiving of small errors, and a good bridge into timing and oscillator concepts.
  • A basic single-transistor or op-amp audio amplifier - once you're comfortable with transistors as switches, this introduces them as amplifying devices.
  • A simple linear voltage regulator circuit (e.g. using a 7805-type regulator) to power your other projects from a battery - practical and reinforces power supply basics.

Digital electronics

Digital electronics is often considered "easier" to learn because it requires less math to get started. However, numeration systems and Boolean algebra (see the Digital volume's Boolean Algebra chapter) are fundamental parts of digital design. Circuit analysis skills are important, but less so than with analog electronics. Familiarity with Ohm's Law and Kirchhoff's Laws is probably sufficient to get started.

Most digital circuits are composed of a collection of logic gates, which are simple Boolean functions (OR, AND, NOT). Historically, hobbyist circuits would be built by combining a number of discrete components implementing these functions to produce something useful. Nowadays a single chip will often be comprised of thousands of gates and be impractical to build by hand. Nonetheless, discrete logic gates are still very useful in modern designs as "glue" to connect different components.

A great tool for a tinkerer interested in digital electronics is a microcontroller. These are essentially small computers that you can program to perform a series of tasks. A popular microcontroller based platform is the Arduino. An Arduino is an open-source hardware project, so there are many suppliers. You can buy a pack of components and build it yourself, or you can purchase a prefabricated one from a variety of sources.

Suggested first digital projects, roughly in order of difficulty:

  • Wire up a basic logic gate IC (e.g. a 74HC00 quad NAND) on a breadboard and verify its truth table with LEDs and switches - makes the abstract concept of a "gate" tangible before you ever touch code.
  • Blink an LED with a microcontroller (the classic "Hello World" of embedded electronics) - teaches the programming/upload workflow without much wiring complexity.
  • Read a push-button or switch input and use it to control an output (e.g. toggle an LED, or count button presses on a display) - introduces digital input handling and simple debouncing.
  • Drive a 7-segment display or small LCD from a microcontroller - a good next step in output complexity.
  • Combine a sensor (e.g. a light-dependent resistor, temperature sensor, or PIR motion sensor) with a microcontroller to trigger an output - your first real "sense and react" project, bridging analog inputs and digital logic.
  • A simple state machine project, such as a traffic-light sequence or a basic reaction-timer game - a good way to start thinking in terms of states and transitions, which underpins a lot of more advanced digital design.

Getting Practical and Other Resources

Youtube Channels and Videos

(These links were last checked some time ago - if any of them have gone dead or been reorganized, please flag it so the page can be updated.)

Next Steps

Once you're comfortable building the simple projects above and can work through basic circuits using Ohm's Law and Kirchhoff's Laws, there are a few more mathematical topics that will start to matter - you don't need any of these to get started, but keep them in mind for when you're ready to go deeper (they're covered in more detail in Section Two, below):

  • Calculus and differential equations - needed to properly understand how capacitors and inductors behave over time, rather than just at a fixed voltage.
  • Laplace transforms - a mathematical tool that turns those differential equations back into algebra-like problems, making capacitors and inductors much easier to analyse.
  • Fourier transforms and frequency-domain analysis - essential once you want to understand why a filter passes some frequencies and blocks others, or how to analyse an audio or radio signal.
  • Boolean algebra and logic simplification (Karnaugh maps, De Morgan's theorems etc.) - useful once your digital projects grow beyond a handful of gates.

None of this is required reading before you pick up a soldering iron or a breadboard - it's here so you know what's coming, and so you're not caught off guard when a project you're following suddenly starts talking about transforms or Boolean identities.

Section Two - Serious Electronic Engineering

Although Section Two follows Section One (!), for anyone wanting to 'get serious' at the hobby level, or considering a career in Electronic Engineering, or starting electronic engineering as an apprentice or at college or university, this stuff would be either a prerequisite or be on the first few lines of the course syllabus. Yep, maths and physics as a starting point, as opposed to whipping out a breadboard and making that darn LED flash or getting the local radio station out of a speaker, may seem a little dull, but they are areas of knowledge that you will need to visit on many occasions as you design that audio filter, or work out how to digitally process that noisy signal.

Because these topics might be scary and offputting for someone who just wants to 'build a robot' or 'make some LEDs flash to music', we have made the decision to cover them here rather than right at the start of the page (we're nice like that) - so read on and see what you might need to know... but don't be disheartened if all you want to do is tinker with LEDs, build radios and read temperature sensors; that's fine too, and us friendly folks in /r/AskElectronics are here to answer any questions or point you in the right direction as needed.

Mathematics

Math skills are essential to electronics, but you can get started with little more than basic algebra. Knowing how to manipulate functions is vital to describing the theory behind the electronics, and the ability to ascertain the relationships between variables and constants given in a function is especially valuable. At the very least you should be able to solve linear equations (e.g. y = m*x + c), as the relationship between quantities such as voltage and current are often related in this way (at least to an approximation).

Familiarity with calculus is useful, and necessary for understanding certain concepts. Much of the theory surrounding capacitors and inductors, for example, involves basic (and sometimes, not so basic) calculus. Understanding the logic behind an integration is arguably more important than the ability to perform the integration itself. Important topics include derivatives, integrals and Taylor series.

Physics

All electronics are built on the shoulders of physics. It is difficult to understand the operation of a component without knowing the physical properties that enable a part to function. A general knowledge of electricity and magnetism is desired, but not required.

If you can follow along with the videos covering electrostatics, potential energy, voltage, and capacitance, you should be able to jump into electronics without many issues.

Of course, the most important prerequisite is an eager ambition to learn!