An electric current is a flow of an electric charge between two points. Imagine it being like water in a river carrying energy. The electric charge in the electrons causes resistors in light bulbs and electric fires to heat up. It also creates magnetic fields in motors, inductors, and generators.
There are two types of electric currents. The first are direct currents (DC) that flow in a single direction like a battery. The second are alternating currents (AC) that periodically change direction. We can increase and decrease the voltage of AC current with transformers.
The greater flexibility of alternating current means we can transport it efficiently through national, high voltage grids, and then step it down to where we use it in our workplaces and homes.
Where Electric Current Comes From
Electric current is a natural phenomenon. We see it in lightening, static electricity, solar winds, and polar auroras. The story of Benjamin Franklin flying a kite with a key attached to the string into a lightening cloud to prove it was electricity is probably fiction. Had it worked, his son holding the string would probably have died because it was raining.
We create electric current by turning a rotor in a generator, or from the sun using solar panels. We can theoretically make as much electricity as we want to, but we do not have the battery technology to store large quantities. Hence we must generate it ‘just in time’ to meet our needs.
How We Control Electric Current Flow
We can compare the optimum flow of electrons through a grid to a garden sprinkler system. We need sufficient pressure to lift the popups in the lawn. However if the pressure is too high, it will break the mist sprayers in the flowerbeds.
Electric current is the same. Too little, and the light bulbs glow brown. Too much, and they explode.
Our power stations and substations are ‘taps’ making sure we receive the right amount of electric current.
Related
1 Comment
Thanks for sharing such an informative blog!