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

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

Diagrams can be drawn in different ways

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

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.

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.

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