I've Been Thinking

A Short Course on Electricity
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  • One of my aims is to inform and educate. I believe that the more knowledge I have of the world around us, the better I will be at my job. You can only reach great heights if you build upon a broad base.

    What is worrying me at the moment is that some people have rather strange ideas about electricity.

    There are some who think that, if you remove a light globe from its socket, then electricity will leak out. They have supposedly proved this hypothesis by sticking a finger in the socket. The ones who survived now believe that there is, indeed, electricity in there and that it is leaking out.

    These people also believe that switches work by applying pressure to the wires so that the current cannot get through and that dimmer switches have a screw action that varies the pressure gradually.

    In order to correct these and other misconceptions about electricity I have developed a short course. Completing this will allow you to understand the subject in such a way as to talk knowledgeably as well as use the stuff safely. The theories might not always be completely correct but if you really want to understand the subject you need to do a university degree like what I done.

    Electricity was discovered when the ancient Greeks rubbed their cats with amber rods. The Greeks called this 'Static Electricity' even though the cat was more often seen running out of the house hotly pursued by an ancient experimenter. Maybe the name was some form of wishful thinking on the part of the Greeks. Whatever, the sparks that emanated from the hurtling cat were man's first feeble attempt at creating electricity.

    Having created static electricity, the Greeks did not know what to do with highly charged cats so they spent their time inventing democracy and building ruins in Athens.

    Many years later an Italian discovered that frogs legs could be made to leap all round the room by prodding them with metal electrodes. This discovery led to the creation of the battery.

    A battery consisted of a number of metal plates with pads of paper soaked in a salt solution. How the connection between frogs legs and metal plates was made is a well kept Latin secret. Why the French now like to eat frogs legs is an even bigger mystery.

    Having heard about the invention of the battery, which is a source of moving electricity, the sort that can travel through wires, Faraday, an Englishman, went one better and invented the generator. He did this by first inventing the electric motor. He then connected it in reverse so that when the rotor was turned in a brisk and energetic manner, electricity came flooding out of the wires. (If you thought that the English have unusual thought processes this should re-enforce that belief.)

    Faraday knew that electricity was coming out of the generator because there was a reading on a couple of meters he had put into the electric circuit. The meters that he used were a volt meter and an amp meter. By a strange coincidence, the volt meter was named after Volta (an Italian) and the amp meter after Ampere (a Frenchman)

    The European nature of electricity does not end there. The ratio of volts to amps is known as resistance, which is measured in ohms (after a German) and is represented by omega, a greek letter. This takes us full circle back to where it all started, Greece. Apart from Benjamin Franklin and his absurd experiment with a key and a kite in a thunderstorm (the man was plainly mad), the Europeans have the subject of electricity all tied up.

    Anyway, enough of the history of electricity. What about some of the interesting properties of this amazing phenomenon. The most common thing that electricity moves in is wire. For normal, low power electricity there are two wires, one red, one black. However, for really powerful electricity there is a third wire, a green one, that carries a special booster so that extra large appliances can be connected. In most houses there is a box containing thin wire that is not strong enough for all occasions. This thin wire is known as fuse wire, because it has a habit of melting, often causing inconvenience late at night and in the cold. When I first discovered this, I replaced the fuse by a short length of fencing wire, after which it did not cause any trouble at all, even when the washing machine went up in smoke after the motor seized and burst into flames.

    When television was first invented, the only electricity fast enough to do the job was the black and white variety. It took a number of years before fast, coloured electricity was developed. Engineers always knew that coloured TV was achievable because, on their way to work every day, they went past traffic lights that changed colour. The traffic lights changed colour only very slowly but at least it was possible and was a constant taunt to TV engineers. The breakthrough came when they realised that traffic lights used coloured light whereas what they needed was coloured electricity. Once this had occurred to them it was a relatively easy task to develop different coloured wires in which the new forms of electricity could run. If you do not believe this, open up the back of your TV and you will find lots of different coloured wires.

    Batteries are very interesting. They have 'direct' electricity instead of the 'alternating' electricity that comes into your house through the mains wires and which then comes out through various sockets in the wall. The reason that it is called direct is that when you buy batteries you put them directly into the radio or tape recorder or other device. When they run down they go directly into the garbage. The mains electricity is called alternating because you can plug your appliance into a socket in the kitchen or alternatively in the lounge, or alternatively in the bathroom. Simple isn't it?

    Electricity can be converted into light by making a small gap in the wire so that the electricity jumps across the gap. This is seen as a spark because the electricity heats the air up as it crosses the gap. A light bulb is simply a small gap surrounded by a large magnifying lens. This theory is in direct contradiction to the dark sucker theory referred to in an earlier report. However science has never been harmed by having alternative theories to explain natural phenomena. You just choose the one that appeals to you more and the world carries on regardless.

    To some people, electric watches have always been a mystery. Even when they manage to open one they cannot figure out how it works. The explanation is quite simple.

    Research is being conducted into the mysteries of other electrical phenomena such as why water and electricity do not mix and the associated problem of how submarines can use electricity safely underwater. Then there is the problem of remote controls. Why do you need one for the television and one for the video and how is it that the two devices do not get confused?

    This current report might be the first in a series on the topic of electricity, if we can get some bright spark with the capacity to generate enough material to illuminate the subject. If we encounter resistance from the odd live wire we are positive that we could transform the topic and fuse it with soldering, unless the reaction was too negative. Alternatively, we could charge for the next one and connect up with others in the field thus producing them at a greater frequency. Now that would be a shock to the system, especially if it was out of phase and it Hertz.

    There are a battery of reasons why this could be the only report, not the least of which is that finding any more puns has become too difficult.

    Bernard Robertson-Dunn, May 2010

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