PRACTICAL ELECTRONICS MASTERCLASS (Mr Bell) 1

Conductors and insulators Some materials will allow electricity to travel through them. We call these materials CONDUCTORS. The piece of metal in this circuit allows electricity to travel through it, so the bulb lights up.

Other materials do not allow electricity to pass through them. We call these materials INSULATORS. There are lots of different insulators, such as plastic, rubber or glass. The plastic in this circuit does not allow electricity through, so the bulb does not light up. For safety reasons, wiring is covered with an insulator to protect you from the electrical conductor inside.

Electrical wiring Electrical wiring in general refers to insulated conductors (copper or aluminium) used to carry electricity. Wiring comes in various sizes and types, depending on its intended purpose, location and the amount of electricity that will be travelling through it. To enable wires to be easily and safely identified, a colour scheme is used:- –Protective earth = –Neutral = –Live =

The future for wiring Nowadays wiring is becoming more expensive (cost of metal) and people want more flexibility with their homes. Therefore fiber-optic and wireless / Wi-Fi systems are becoming more commonly used in modern homes. Especially with computers and the internet Wireless charging is the newest development they are working on

Wiring techniques – Heat shrink Heat shrink is a mechanically expanded extruded plastic tube made of nylon, which shrinks when heated. It is available in various sizes and colours. The un shrunk tubing is fitted on the wire before making the connection, then slid down to cover the joint after it is made. The side of a soldering iron or a lighter can be used to shrink the nylon.

Wiring techniques – Cable ties A cable tie, also know as a zip tie or tie wrap, is a type of fastener designed for bunching electric cables or wires together. They are available in various sizes and colours Remember to cut off the extra tail to avoid injury

Wiring techniques – Crimping A crimp connection is a type of solder less electrical connector. The stripped wire is put into the crimp, which is mechanically compressed using crimping pliers. They are easier, cheaper and faster than soldered connections. They are used for various purposes such as: –Connecting wires to a screw terminal – Providing a quick-disconnect terminals

Extension: Twist tie A twist tie is a metal wire that is encased in a thin strip of paper or plastic. They are commonly used to tie bags but are also used for wiring.

Extension: Rapstrap (Dragons Den) Rapstrap is a new system of securing and bundling together cables. It can be reused and the excess that is cut off can be used again. Invented by Andrew Harsley, who appeared on the Dragons Den in 2008 and is the biggest success story yet.

Extension: Velcro straps Velcro straps function in the same way as cable ties, twist ties and the Rapstrap. Advantages: –Reusable –Can be labelled Disadvantage: –More expensive –Not suitable in extreme weather conditions

Extension: Spiral Wrap Spiral wrap is an expandable binding that simply wraps around cables to create a cable loom. Its advantages are that it can hold all of your wires in one spiral wrap and any wires can be branched out when and where needed.

Extension: Cable markers Cable markers are an invaluable item to use, to help organise your wiring. They are available in various sizes, colours, numbers, letters and you can self make your own markers.