Electronics can be mystifying subject. For those of us, who weren’t blessed with a mechanical mind, or who don’t have a physics background, all the talk of circuits, resistors and diodes could be confusing and even downright scary. However, having just basic knowledge of electronics can make all the difference when it comes to having to change the plug.
Wikipedia defines electronics as “dealing with electrical circuits that involve active electrical components, such as vacuum tubes, transistors, diodes and integrated circuits.” It is widely used in information processing, telecommunication and signal processing because it is able to amplify weak signals.
Electrical signals can be classified as either being an alternating current (AC) or a direct current (DC). As the name suggests, and alternating current is electricity that constantly reverses as it flows through the circuit. Most basic electronic circuits, however, use DC electricity, in other words electricity that flows in one direction between the power source (or positive voltage) and the ground.
Electricity needs to flow through a circuit to be utilised. A circuit is a complete and closed path through which electric current can flow. Once that path is opened, electricity will cease to flow.
Electricity in a circuit, without some sort of resistance, is useless. There needs to be something between the positive voltage and the ground that adds resistance to the flow of electricity and converts it to something usable. Removing the resistance will result in a short circuit. A short circuit can lead to your power source (often a battery) and/or circuit overheating, breaking, catching on fire or exploding.
Circuits can be wired in series, or in parallel. In series, things are wired one after another, forcing the electric current to pass from one thing to the next. In parallel, things are wired side by side, allowing electricity to pass through all of them at the same time.
There are many different elements in a circuit and each one has a different purpose.
- Resistors are poor conductors and are therefore used to control the flow of current from a voltage source;
- Capacitors also control the flow of charge in a circuit, but they also have the capacity to store charge, like a small battery, releasing electricity when there is a drop in flow;
- Diodes are polarised components that only allow electrical current to pass through them in one direction;
- Transistors takes a small electrical current and amplifies it so that a much larger current can pass between its collector and emitter pins;
Finally, what do we use electronics for? The short, uncomplicated answer is a myriad things, including radio transmitters and receivers, television, radar and microwave technology, specialist audio equipment and much, much more. In fact, it is hardly possible to envision a world in which electronics doesn’t play a major role, and nor would we want to.