The vast range of available resources for the teaching of electricity in the primary school can be confusing. BBC education offer useful animations to support learning in this area such as www.bbc.co.uk/schools/scienceclips/ages/10_1 1/changing_ circuits.shtml. It is possible to build up an effective set of compatible resources if you stick to a few simple rules:
Keep it simple! Go for simple components rather than packaged sets. The packaging and connectors that come with electricity 'sets' can often confuse and disorientate children.
Buy components that have the same (or nearly the same) voltage ratings.
Buy enough components to allow for breakages.
Batteries don't last for ever! Make sure that there are enough fully charged batteries before you start. Rechargeable batteries are discussed elsewhere.
It is important for the children to see how the components are connected, and how the electricity is able to flow, in any circuit that they make.
The three basic elements of any electricity kit are the power source, the output components (the bits that do things) and the connectors.
Power sources
My preference is for non-rechargeable batteries. Power packs (transformers) that can be plugged into the mains supply to provide a low voltage require you to find several sockets, and to contend with trailing wires. Small batteries range from I .5V to 9\/. A battery tester is also an essential item!
Output components
Your key output component is the bulb or lamp. This will need to match the voltage of the battery as closely as possible. The best matches are:
Bulb Battery
1.5V 1.5V
2.5V 3V (two 1.5V batteries)
3.5V three 1.5V batteries in a battery box
6V 6v (or four 1.5V batteries)
Using a 2.5V bulb with a 3V battery (two I .5V batteries in a battery box) means that you have a nice bright bulb without too much risk of it blowing; and when the battery begins to deteriorate, the bulb continues to glow well for a long time.
You may also need: buzzers (3V); motors (3V); light emitting diodes or LEDs of different colours (3V); ES (Edison screw) bulb holders for the bulbs.
Connectors
Crocodile clips can be vicious. I have known some children to consider them excellent clip-on earrings — but not for their own ears! Even when used properly, they can give little fingers a nasty nip. If you must use them, find ones with the plastic sleeve covering most of the jaw.
Connecting wire can be bought by the bobbin and cut using scissors (not your best ones) or snips. Use wire strippers (the ones with large teeth are best), not your own teeth, to bare the ends of the wire. If you are using multi-strand wire, twist the ends together to prevent them getting tangled up.
Switches are very important. You will need to provide several types, in particular:
Toggle switch — turn it on and it stays on.
PTM (push-to-make) switch — only on as long as you hold it down.
Reed switch — either normally on or normally off (the first type being more useful), and operated by the proximity of a magnet.
Dimmer switch — in effect, a variable resistor which controls the flow of electricity.
Collections of electrically powered toys are also useful, as are collections of materials that the children can test for conductivity. Appropriate electrical components can be collected from educational suppliers such as: www.tts-group.co.uk
Freebies!
Electricity companies will often supply schools with free resources to support an electrical safety campaign: booklets, posters and videos. These are intended to help children identify and avoid hazardous procedures and situations, and to demonstrate some consequences of not following safe practices.
Websites
Free electrical safety information can be obtained from:
www.switchedonkids.org.uk/pt_resources.html
http://powerup.ukpowernetworks.co.uk/
www.powerwise.org.uk/
www.bbc.co.uk/schools/scienceclips/ages/10_1 1 /changing_ circuits.shtml
Books and CD-ROMs
Scholastic Primary Science: Turn It On!
Scholastic Primary Science: Conserve and Preserve
Scholastic Primary Science: Power Station