UK Technology Education Centre
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3: The Problem

Sometimes we go to use an electrical appliance and discover that it does not work.

The most common fault is a "blown" fuse. How can we check this?

We have already seen that a fuse is really a thin wire inside a glass or ceramic cartridge. As ceramic fuses are the most common type, and as it is impossible to look into them to see if the wire has melted, we need an electronic device to test ceramic fuses.

The Brief

Design and make a device that will test whether or not an electrical ceramic fuse has "blown".

To make the fuse tester you will need to make an electrical circuit. In electronics, a circuit must be complete for electricity to flow around it. To be complete, the circuit must form a continuous loop.

You will need to investigate a simple circuit which uses a battery, a bulb, some wire, and a switch to turn the bulb on and off. You could model the circuit below in the school workshop, perhaps using a transformer or power pack instead of the battery.

When a circuit diagram is drawn, internationally agreed symbols are always used to represent the components so that everyone can understand them.

Further Reading
About Simple Electrical Circuits

2: The Fuse
4: The Light Emitting Diode

The Starting Point

The Pivot Point