1. How Relays Work
WALT: Explain how a relay works and why it is important STARTER: Hot seat

2. Relays
Connects a low-power circuit to a high-power circuit using an electromagnet
You switch on the low-power circuit and the relay then causes the larger circuit to be complete and it turns on high-powered circuit
It is safer – you do not need to come into contact yourself with the high-powered circuit
Used in car motors

3. Diagrams can be drawn in different ways

4. Circuit Symbol for a Relay
(not in C.E)

5. Now set up your own circuit with a relay
The ‘control’ circuit (low-powered) circuit will have a cell, a push switch and a relay
The high-powered circuit should have a motor (and battery). In real life these would be a large motor and a large battery.

6. When finished
Draw the circuit diagram and a short explanation of how it demonstrates a car motor circuit
SPDT switch
Design a circuit that switches a light on OR a buzzer on, using an SPDT switch.
Draw the circuit diagram
3. Design a circuit of your choice – Design a circuit with a purpose (e.g. burglar alarm, different switches for a light in different parts of a room). Draw the circuit diagram and explain it.

7. Plenary
Draw a spider diagram with at least 10 facts you have learnt about the topic of circuits
Circuits .