Current Electricity
Electric current has become a powerful force in human society in the last two hundred years. It is used to extend daylight hours for reading and working. It powers virtually every appliance in our homes. Refrigerators keep our food fresh for days or weeks now. In the past, cold cellars were used by some but without any where near the effectiveness. Freezers keep frozen food perishable for up to a year and allow us to stockpile larger quantities to reduce in my case long trips to the city. Computers and the internet with which I am writing this hub would be impossible without electric current. What would young girls do without their hairdryers, curlers and straighteners? Our blackberries and IPhones would not run without electric current. Our entire society is indelibly intertwined with this phenomenon.
Children and adolescents, with their immeasurable curiosity love to investigate in a hands-on way. Allowing them to investigate a concept such as current electricity upon which their entire world hinges, will give them a greater understanding and hopefully eventual wisdom in a force upon which we rely so greatly rely but which presently has devastatingly negative consequences in terms of the pollution created by its mass production.
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How to Assemble a Simple circuit board that Clearly Demonstrates Simple Circuits
Materials:
•peg board or at least 1/4 inch plywood for attaching the components
•plastic covered copper connecting wires with attached alligator clips
•screw-base lamp holders (I used ones that were for E-10 bulbs)(3)
•screw-base bulbs that will fit into your lamp holders (try to get as low voltage bulbs as possible)(3)
•battery receptacle for at least two D-sized batteries
•D batteries (at least 2)
•knife switch
•screw driver to match screw heads
•screws long enough to penetrate the components and firmly attach them to the peg board
Assembling the Circuit Board
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Steps for Assembling the Circuit Board
1.Cut a piece of peg board to your desired dimensions after spacing out the following components on the board: battery receptacle, knife switch, three lamp holders. I made mine 18 inches by 18 inches in order to be able to clearly demonstrate more complex circuits. The board was cut using a table saw. 12 inches by 12 inches would probably be adequate for showing simple series and parallel circuits.
2.A wooden frame is not required for the operation of your circuit board but it does provide a finishing touch and a means of storing the connecting wires, bulbs and batteries.
3.A wooden frame was also attached to the peg board to lift it off of the surface to allow components to be screwed into the peg board.
4.A groove was created in the centre of each wooden side to fit the peg board. The four corners of the board frame were screwed together using a drill.
5.After the components were laid out for adequate spacing, the battery receptacle, the knife switch and the screw-base lamp holders were screwed onto the peg board using a drill to pre-make holes and then a screw driver to screw in the screws.
6.I left room for a second batter receptacle to be installed. Two D batteries provide only 4V of potential difference which may result in dimly lit bulbs in the series circuit once you hook up more than one bulb depending on the voltage requirement of the bulbs used.
7.Three lamp holders are screwed into place in a single line in front of the knife switch. Leave ample space to allow for connecting wires to be attached in varying configurations.
8.The positive lead from the battery holder is hard-wired to the knife switch to reduce the number of alligator clip connecting wires required. Strip a bit of the plastic coating from the wire and make a wire loop.
9.Unscrew one of the screws of the knife switch and wrap the wire loop around neck of the screw. Tighten the screw gently again using the screw driver.
10.Check each component to make sure each is securely screwed onto the peg board.
Creating a Series Circuit
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Terminology of Basic Current Electricity
Current electricity is the movement of electrons from a source of electrons such as a battery or solar cell along a path such as a copper wire.The electric current carries energy from the source to an electrical device called a load (light bulb, motor) that converts the electrical energy to a useful form.
•a light bulb converts electrical energy to light energy
•a motor converts electrical energy to kinetic energy.
Once the current passes through the load, it returns to the source where the cycle begins again.
Each electrical circuit contains four main parts:
•source of electrons such as a battery or solar cell
•a switch to turn the flow of electrons on and off
•connecting wires (usually copper) that allow the electrons to flow from the source through the load
•one or more loads which convert the electrical energy to a useful form
There are two main kinds of electrical circuits:
•series circuit in which the current can be traced through only one path from the source, through the load and back again to the source.
•parallel circuit in which each load has its own mini-circuit; in other words, a separate path can be traced for each load present; if there are three loads, then there are three separate paths for each of those loads.
Creating a Parallel Circuit
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