Microcontrollers and YOU!

Our modern world would be nothing like it is today without electricity. Electricity has enabled man to create devices that truly work on an atomic scale. We can cram more power into smaller devices with more and more capabilities. What intrigues us most about electricity is that is based on such a simple concept.

Likes attract, opposites repel. Electricity is made from electrons (REALLY?) these electrons have a negative charge. The fundamental of electricity is to creates charge difference that induces electrons to flow. With this charge difference work can be done. Voltage is defined as the potential difference in charge, so where there is voltage there can be work done. By connecting two objects with a potential difference with a conducting material (wire) the charge evens out as the electrons flow from negative to positive. Now, when you take this idea and add fun things like semiconductors, you get our modern world.

The Fundamentals

All flowing charges are made up of two things, Current which is measured in amperage and voltage(potential difference) measured in volts. For a circuit to be useful there must be some type of resistance, without resistance, your current flows as fast as it can and as much as it can. This wastes energy and you might end up vaporizing your wire due to so much current and heat. So we invent these things called resistors.

A resistor just simple, resists electrical flow and slows things down. They produce a limit on current and they allow us to supply reasonable amounts of current to devices without them all catching on fire. Resistance is measured in Ohms.

The Formula

V=IR is one of the most important formulas you can ever get to know. It states that Voltage(in volts) is equal to Resistance(in ohms) multiplied by Current(in amps). This lets you determine how much resistance you need to supply to a voltage to limit to a set current, or any other adaptation.

Another fundamental component is the Capacitor. Capacitors are measured in Farads. The job of a capacitor is to hold a charge. It does this by placing opposing charges on opposite plates separated by a dielectric(insulator). By holding a charge a capacitor stores energy. Although they don't hold nearly enough energy to work as batteries, their main advantage comes form the fact they can discharge extremely rapidly. Common uses for this ability are the flash in your camera. The camera charges a large capacitor and dumps all the electricity at once into the light bulb, creating an intense flash. Capacitors are use in timing circuits, smoothing out ripples in power supplies, filtering frequencies and storing energy. Capacitors are extremely useful and find their way in practically every circuit.

The inductor. This component is about as simple as you can get. A inductor is simple a coil of wire. The special thing about a coil or wire is the fact it builds up a magnetic field when charge is put though it. As the current through the coil changes, the magnetic field resists this change. Because of this an inductor, like a capacitor can store energy in a magnetic field. Inductors are measured in Henrys. Inductors are primarily use to regulate frequencies since a capacitor and inductor in series creates a harmonic circuit.

With these fundamentals we were able to create simple devices such as radios and gain the ability to transmit power, generate locomotion and light our homes. It wasn't until the invention of the semiconductor and the transistor that our modern lives really took off.