Monthly Archives: November 2015

What’s A Circuit Again?

Don’t be ashamed; despite the fact that your life totally relies on your access to a myriad of objects that utilize circuits to manipulate electricity for results that are now taken totally for granted, you are not alone in not understanding even the basics of electrical engineering; weirdly enough, most people don’t, and I guess it’s because they can get by just fine without that knowledge. However, if a meteor hits the Earth and corrupts its atmosphere in such a way that only those with a rare and previously unnoted genetic mutation can breathe the new air and you have that mutation, you’re likely going to have to contribute to building society up again to become what it once was which means you should know the basics of mechanical engineering. Or at least someone should. Here’s a quick bit about how circuits work:

Circuits use energy made by electric currents. They are composed of closed paths or loops around which that electric current can flow. Conductive materials like copper metal allow for electricity to flow freely through them. Insulators that don’t allow electricity to easily pass through them, like rubber or plastic, are called insulators.

copper electricityWhy is copper a conductor and plastic an insulator? It all has to do with the chemical structures of the materials and the physical properties of electricity itself. A current of electricity is a steady flow of electrons, which carry electrical energy along with them when they move in the form of a small electric charge. When electrons can move through a substance easily, that substance is a conductor. Conductors tend to have chemical structures in which there are a lot of free electrons easily separated from their parent atoms, which makes electron movement and the carry of electric charge that much easier.

Insulators, on the other hand, have chemical structures in which the electrons are more tightly bound, hampering the movement of electrons.

No matter what the material, electricity will not flow without something to push the electrons, known as the electromotive force, or EMF. A battery, for example, creates the electromotive force that makes a current of electrons flow. Electromotive force is just another word for voltage.

Given a circuit, electricity can flow in two different ways; it can have a direct current or an alternating current. Alternating currents are more powerful and generally used for larger appliances, while direct currents are used for kids toys or simple flashlights.

motorThe ability to run electricity through a circuit opens up so many other new abilities. For example, when electricity is run through a wire, it creates a pattern of magnetism around the wire. That magnetism is utilized in electric motors, which are composed of a cylinder packed with magnets and a core made of iron wire. When electricity runs through the iron core, it becomes magnetically charged in such a way that it interacts with the magnetic cylinder by spinning. The force generated by the spinning can was clothes in a washing machine, spin a drill and drive machinery.