The world of electricity is a mystery to most people. We all know that it exists, and we are all very happy that when we flick a switch the lights come on or the oven starts. But quite what all the pieces are behind the scenes that make it work are unknown to most people. So, while we may have heard of terms like solar, inverter or variable resistors, many people have no idea what any of these things are – or the processes behind them. So, to help unpack some of the basic mysteries of electricity, here are a few simple components and apparatus explained and unpacked.
Switching current
There are two types of current that we typically encounter. There is AC and there is DC. The former stands for alternating current while the latter is direct current. Direct current is what you get with batteries or solar panels where the current goes in one direction – that is from positive to negative. With alternating current, the current flows in multiple directions with varying magnitudes. Alternating current is typically what you have in your house if you are wired to the mains. These two types of current have similar outcomes, in that they are both about the movement of electrons through a circuit, but in order for them to work harmoniously, an inverter is used. For example, a 24v inverter would take electricity from a battery and feed it into an AC circuit. You can get more information at Elinz.
Alternators
Anyone who has worked on a car will have heard the term alternator. An alternator is not the same as an inverter. Instead the former is a component that harnesses mechanical energy and turns it into alternating current. In short, an alternator is a generator while an inverter is a transformer.
Faraday Cage
Named after the renowned English scientist Michael Faraday, this ‘cage’ is a shield that is made from materials which conduct electricity. It is used to block electric fields or radio waves and was invented as long ago as 1836. The easiest example of a Faraday Cage is a motorcar. If a car is struck by lightning the passenger inside the vehicle will be unharmed because the metallic exterior of the car causes the electricity to move around the outside of the car, cancelling its effect inside the vehicle.
Transformers
These are important parts of most electrical systems as they transfer electrical energy from one circuit to another. Transformers can be found in both simple and complex electrical circuits, from small hand-held devices to major national power grids. The primary reason for the presence of transformers is to step up or step down the voltage of electricity being transported in a grid. By way of example, it is much easier to move electricity over large distances if the voltage is high. However, this is very dangerous and not an ideal scenario for domestic use or consumption. Thus transformers, often found at substations, will be employed to lower the voltage once the electricity has travelled from the source.
