Basics of Switches and Electricity
Switches are an important part of electrical circuits. They serve to make the circuit complete when it is needed, and to break the circuit when the device should not be working. Switches control the flow of electricity through a circuit, and are included in everything you can imagine, from lighting in the home to computers, microwaves, and games consoles.
Learning the basics of switches is essential if you want to make sure that you can build electrical circuits – whether that is simple prototypes on a breadboard, or something more sophisticated.
Electrical circuits allow the currents of electrons to flow from a battery, through the circuit, and back to the battery – or through an entire mains circuit. The circuit itself is made up of the load and the power source. The load could the the light bulb that lights up when the switch is flicked, or it could be the speaker that buzzes when triggered by a sensor. The important thing is that the power source has to be able to send power all the way around the circuit, from a negative terminal, through the circuit and to the positive terminal. Learning the basics of switches means understanding that the electrical switch can make or break that circuit, and if the circuit is broken then the power will not flow to the load.
Electrical switches follow quite a simple design. They all work in much the same way – whether that is a toggle, or a button. When the switch is in the ‘on’ position it makes the circuit. When it is in the ‘off’ position, the circuit is broken.
The one main difference is dimmer switches and three-way switches. With a three-way switch, there are two separate switches that both control the device. With a dimmer circuit, the switch regulates the amount of power that flows through the circuit – although even then, when it goes to the ‘off’ position, the circuit is completely broken. The switch will then move to complete the circuit when the device is turned on, with varying levels of resistance between ‘just on’ and ‘fully on’. The more resistance, the less power, so the dimmer a light attached to the circuit would be.
A lot of people learning the basics of switches are interested in then for the purposes of DIY at home. They want to know how to add an extra switch at home, or to change an existing switch. Really, if you’re just learning the basics of switches it may not be the best idea to worry about doing full electrical work – because that is something that can be quite dangerous if you don’t know what you are doing. Learn with battery operated tools and with breadboards, and seek professional guidance before you try to do anything more sophisticated. Electricity is dangerous, and mains electricity even more so. If you get things wrong then your lighting or wiring system could be a fire hazard at best, and could leave you at risk of potentially fatal electric shock at worst.
If you’re just academically curious about how switches work, though, then think of it this way. In the home, your power source is the mains – or, more locally, the fuse box. For an electrical appliance to work it needs to be connected to the fuse box. The appliance has a switch, and the switch accepts power from the supply and connects it to the load. A special cable connects the power source to the switch, and the electrical outlet. There are three wires – one live, one neutral, and one ground. The live wire is connected tone of the terminals and to the switch. The neutral wire connects the other terminal to the load, and the ground terminal connects to the electrical outlet and is used to ‘earth’ it.
Inside the switch there are two electrical contacts. When the switch is triggered, the contacts link the two terminals. When the switch is turned off, the contacts move to break the circuit. Usually, there are markings on the switch that tell you whether the appliance should be on or off.
Switches can slide or be sprung, or be flickable. There are a few different designs to choose from. The switch is one of the first electrical components that most people ever use and learn about when they are first experimenting with circuits. It is an easy thing to learn, and it will help you to understand other things such as logic gates. If you play with dimmer switches then you will also get to learn about resistors. Capacitors are another electrical component that it is worth learning about.
Switches are quite easy to understand, but they are useful for people who want to learn about the way that electronics works. Circuits and logic are the ideal thing for people who are interested in careers in electronics or engineering. Having an understanding of how circuits work can help with more complex ideas including programming and logic arrays.
If you’ve not experimented with circuits before, then you should give them a try. Breadboards can be an effective way of learning how circuits work and prototyping them. They are also useful for people who want to experiment without using a soldering iron. As you gain confidence you can try programming and learning about other things like And, OR and NOT gates. These are all essential parts of making complex circuits, and becoming conversant in them will serve you well whether you are a hobbyist or someone who is looking to gain real skill in the world of circuitry. Knowing the basics will make it possible for you to try to work with basic battery powered appliances, fix minor things that have gone wrong, and work more efficiently with the tools you have available to you. It doesn’t take long to learn, and it’s a skill that could well save you a huge amount of money over time.
