Electrical Circuits

Electrical Circuits

• A path where electric charges move along (through wires).

Parts of a Circuit

• The four main parts of an electric circuit are:

1. Energy Source – Gives the circuit its energy. (eg. a battery)

2. Conductor – Is a device that allows electricity to pass through it. (eg. a wire)

Parts of a Circuit

3. Load – Is a device or appliance that uses the energy. (eg. a light bulb)

4. Switch – A device that turns the flow of electrons in a circuit on or off.

Electric Circuits

Closed Circuit – Allows electrons to travel through an unbroken circuit and back to where they started.

Circuit is ON

Electric CircuitsOpen Circuit – Has a break in the

path along which electrons flow.

Circuit is OFF

Electric Symbols

• We use diagrams and symbols in electricity to represent the actual wiring.

• WHY??????

Symbols to Know

SymbolSymbol DiagramDiagram

Conducting Conducting wirewire

Open SwitchOpen Switch

Closed Closed SwitchSwitch

More Symbols

SymbolSymbol DiagramDiagram

AmmeterAmmeter

VoltmeterVoltmeter

A

V

The Last of the Symbols

SymbolSymbol DiagramDiagram

Light BulbLight Bulb

CellCell

BatteryBattery

Longer line is positive endShorter line is negative end

Direction of Flow Review

• Electrons are: –Repelled from negative terminal.–Attracted to positive terminal.

• Why?

Remember…

Negative is attracted to positive!

Which way do electrons flow?

1.Cell (source)

2.Closed switch (control device)

3.Light bulb (load)

4.Conducting Wire

Label This DiagramLabel This Diagram

1

3

2

4

One More to Label

1

5

4

32

1.Battery

2.Conducting wire

3.Light bulb (load)

4.Open switch

5.Light bulb

What Now?

• Let’s Build a simple circuit!!

Drawing Circuit Diagrams

• There are some conventions (rules) to follow when drawing circuit diagrams1. connecting wires are generally shown as straight

lines or 90º angles

2. Symbols are used to represent all components such as control devices, outlets, electrical loads, meters

Circuit Diagram Examples

What is similar what is different?