- Relays
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Objectives:
- To be able to explain how a relay works
Timing: 1 lesson
In the "Heart Attack Patient" section, you will look at electronic circuits. These produce very small currents which are fine for switching on LEDs but are no good for switching on motors as they need large currents to operate. The device which uses a small current to switch on a circuit in which a larger current flows is called a relay. They can be used to isolate a low voltage from the high voltage mains. You need to find out the circuit symbol for it and be able to explain how it works. The following sites will help: http://www.bbc.co.uk/, http://www.antonine-education.co.uk/ and http://electronics.howstuffworks.com/relay.htm.
You could do the following worksheets:
"Relays"
