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What is my project this term? 

What is a Design Brief?

A design brief is a short description of what it is I am expected to design and manufacture (make), who it is for, and any important requirements that it must have.

My Design Brief

• Design and manufacture an electronic voice recorder. 

• The device must be small enough to fit inside my pocket.

• It must be able to record at least 20 seconds of audio and play it backwards so that I can hear it clearly. 

What is electricity? 

• Electricity is a natural phenomenon, and a form of energy. 

• It can be used to ‘power’ devices to make them work.

• Electricity occurs all around us, but until recent human history it was difficult to produce and control.

• Electricity is the continuous flow of negatively charged electrons around an object, usually  in a ‘circuit’.

• The amount of flow through a wire is called the current. Current is measured in amperes or amps. 

• The ‘force’ behind the flow is called voltage. It caused by a difference in electrical ‘potential’, between two sides of an electrical circuit. It can be thought of as the pressure or force behind the electrical flow. Voltage is often referred to as potential difference.

• When a component or wire tries to slow down or stop the flow of electricity, this is known as resistance. 

Resistance and Ohms Law

Current flow can be thought of as 'how much' electricity is flowing around a circuit. Too high a current and you might damage the electronic components inside. Too little and they may not work as they have insufficient energy to 'power' them. Current is measured in 'Amperes' or 'Amps' (symbol big 'I').

Voltage is also known as 'potential difference'. It can be thought of as how much force there is 'pushing' the current around the circuit. If there is no potential difference between two electronic components in a circuit, then there can be no current flow. This means that voltage must be directly related to current flow. If one changes, then the other must also change. Voltage is measured in Volts (hence the name), It has the symbol big 'V'.

Finally, resistance can be thought of as a force trying to slow down the current flow. If resistance affects current, then because current and voltage are related then so must resistance affect voltage too.

This relationship is called Ohms law.