Electronics 101 - Part 2

Introduction

In this series of guides I'll be introducing you to the concepts and practicalities of electronics, and how to use this essential and rewarding skill to add a little something special to your PC. Each part will introduce a few concepts and then a practical project or skill that demonstrates these.

In this part we'll be looking at circuits, how they are wired, prototyped and some of the basic building blocks they are made of.

Concepts

Now that we've learnt what electricity is (in Part 1) we're going to move on and look at how it actually behaves when in a circuit. A circuit is simply a group of components and/or wire with a positive and negative side to allow a voltage to flow.

But which way does electricity flow in a circuit? Well the answer to this is both. When thought of as flowing from positive to negative the term given is Conventional Current, when thought of as flowing from negative to positive the term given is Electron Current. Strictly speaking the latter is more accurate however when following a diagram or building a circuit you should always apply the idea of Conventional Current.

Electricity behaves differently depending how a circuit is connected. Circuits can be connected in three ways. We've included a diagram showing how Voltage and Current is distributed in each arrangement, in each diagram a battery is shown at the top which provides voltage or current and components which use it at the bottom.

Series: This is where two or more components are connected one-after-another. In this arrangement voltage is shared (often unequally) between the components...




...where-as current remains the same for all of them:


Parallel: This is where two or more components are connected side-by-side (or across) each other. In this arrangement voltage remains the same for every component...


...where-as current is shared out as needed:


Series and Parallel: Simply a combination of the two, to predict how electricity will be split or shared in this type of circuit split it up into smaller component groups that are arranged in series or parallel and build up a picture of what's happening.