Electronic Components – Capacitors

One of the most important inventions in human history is that of the capacitor. They’re a key component in every electronic device and without them it would be pretty much impossible to have anything in the modern world. On a motherboard, capacitors primarily condition DC voltage to other parts of the computer like the video card, hard drive and so on making it so they can run. Generally though, a capacitor sort of holds the electric charge (like a battery) for a specified amount of time and this can be helpful for timing the operation of something like a light or a sound in an electrical circuit and they’ve certainly come a long way since their invention in the 1740’s.

Credit for inventing the capacitor goes to Ewald Georg von Kleist and his first capacitor was dubbed the “Kleistian jar” and later was more popularly known as the Leyden jar. Von Kleist was experimenting for ways to store electricity and although the understanding of electricity at the time was not correct, it led to the novel use of two pieces of conductive material being separated by an insulated layer which basically creates an electrostatic field that stores the energy, thus building a charge. The experiments of von Kleist were tried and eventually duplicated by his peers Daniel Gralath and also Pieter van Musschenbroek at the University of Leyden. As primitive as it was, the Leyden jar was said to deliver a painful shock if handled incorrectly, and with the ability to store up to 60,000 volts that’s hardly surprising. If you’re curious how such a simple device can work, you can make your own. Don't worry, this one probably won't be that powerful.

Today’s capacitors are widely different from where they started. They’re much smaller, for starters, but they’re also made of better and more advanced materials. The conductors today can be made of thin metal film, like aluminum, and the non-conductive dielectrics are typically glass, ceramic or plastic. These materials are specially designed with electrical purposes in mind so they do the job much more efficiently than the early conductors could. Specialized films are sometimes used to prevent short circuits with self-healing materials. Aluminum capacitors use an acidic electrolyte that degrades the dielectric over long periods of time. Ceramic capacitors allow for higher voltage and prevent issues with the dielectric. Polymers can be used to provide a much longer life. Each type of capacitor has advantages and disadvantages in certain situations so proper planning will help ensure success.

Capacitors today have traveled a long road since their invention several hundred years ago and they are one of the essential building blocks in today’s electronic world. Each style has its own specs that it’s designed for and materials that it’s made out of. When you identify the correct capacitor it’s important to find one that’s a good quality component. Here at EIO we carry brands like NTE, Velleman and others that are known in the industry for their quality. Make sure to leave us some product reviews for the ones you use!