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Dave Investigates

Here’s a torch, that’s better we can see what we are doing now.

This is the cupboard under the stairs where our electricity meter and the main circuit breaker box are. The electricity supply that runs around the house is called a ring main. Ring – because it has to join up in a ring to complete the circuit or the electric current cannot flow through it, and main – because it carries ‘mains’ electricity.

Apart from the fact that torches usually run on 1.5 volt batteries and mains electricity is 230 volts they both work in the same way. The house ring main is controlled by switches – to turn the lights and plugs on and off. The torch circuit is also controlled by a switch.

Never attempt to touch a fuse or circuit breaker unless you are supervised by a responsible adult.

The ring main has powerful electricity flowing round it and so we need fuses to keep us safe. Torch batteries are much less powerful than the ring main so we do not need fuses to keep us safe.

I can see from the circuit breaker that the problem is with the downstairs plugs. Ah! I thought I heard a fizzing sound just before the lights went off, I reckon the problem is the lamp next to the sofa.

Well first I have to turn the main electricity supply off and then I have to go and check out what the problem is.

Ask Julie

Dave’s torch runs on 1.5 volt batteries. The proper name for a battery is a cell.

How does a cell work?

Cells are used to store current electricity. Inside a battery are chemicals that make positive and negative charges. These charges collect at the opposite ends of the battery indicated by the + (positive) and - (negative) signs. the force which the batteries move electrons around a circuit is measured in volts (V).

What does a torch circuit look like?

Dave’s torch runs on a simple circuit. The negative terminal of the cell is connected to a switch, which is then connected to a light bulb, which is then connected back to the positive terminal of the battery. This is what it looks like with the components in place:

What is a circuit diagram?

Circuit diagrams are used to show the components of a circuit in a very clear way. They are a map of an electric circuit.

Different symbols are used to represent the components of a circuit:

The torch circuit diagram would look like this:

Next page: Problem solved!

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