EDUCATIONAL TRAINING CENTER
BASIC ELECTRICITY
We all use electricity every day. From the moment our electric clock wakes us up in the morning until we turn the light off for bed at night. It has become so common place, that we take it for granted. I am going to discuss the various parts of an electrical circuit and what happens when you have all the pieces connected correctly.
Main Properties of Electricity
•pressure (voltage)
•current (amps)
•resistance (ohms)
Electricity begins in atoms. These are the tiny microscopic building blocks that make up everything. We will talk about atoms in another article, but for now just bear with me. Atoms are made up of protrons, neutrons and electrons. It is the electrons that we are most interested in. The process of atoms moving their electrons in a path (or circuit) is electrical current.
Voltage is the force that makes these electrons jump from atom to atom. In a typical DC (Direct Current) circuit such as a flashlight, the voltage is created by the battery. In the diagram, you see there is a battery which is connected to a light bulb. The voltage from the battery is stimulating the electrons in the circuit to give up electrons. The electrons are moving from the negative side of the battery (the black line shown with a minus “-” sign). When the electrons reach the light bulb, it converts these extra electrons to light and then passes them back to the battery through the positive line (the red line shown with a “+” sign).
Resistance slows down the flow of electrons. We get some resistance just from the wires coming out of the battery. The smaller the wires the greater the resistance. The main source of resistance in our example is the light bulb itself. The filament causes the flowing electrons to enter a smaller space.
Who Discovered Electricity?
The history of electricity goes back more than two thousand years, to the time the Ancient Greeks discovered that rubbing fur on amber caused an attraction between the two. By the 17th century, many electricity-related discoveries had been made, such as the invention of an early electrostatic generator, the differentiation between positive and negative currents, and the classification of materials as conductors or insulators. In the year 1600, English physician William Gilbert conned the term electric, from the Greek elektron, to identify the force that certain substances exert when rubbed against each other. While many believe Benjamin Franklin to be the father of electricity, current findings seem to show otherwise. In 1752, Franklin is said to have performed the famous experiment of flying a kite during a thunderstorm, which led to the discovery thatlightning and electricity were somehow related. Modern scientists know this to be something of a tall tale, since being hit by lightning would have been fatal. It's likely that Franklin was actually insulated, away from the path of lightning. The kite experiment helped Franklin establish a relationship between lightning and electricity, which led to the invention of the lightning rod. Benjamin Franklin went on to observe other phenomena related to electricity, but many believe that he didn't actually discover its true nature. In 1800, Italian-born physicist Alessandro Volta constructed the voltaic pile, later known as the electric battery, the first device to produce a steady electric current. It was Volta, not Franklin, who discovered that certain chemical reactions could produce electricity. Volta also created the first transmission of electricity by linking positively-charged and negatively-charged connectors and driving an electrical charge, or voltage, through them. It wasn't until 1831 that electricity became viable for use in technology. English scientist Michael Faraday created the electric dynamo, a crude precursor of modern power generators. This invention opened the door to the new era of electricity. A few decades later, in 1879, Thomas Alva Edison invented the light bulb. |
