Electricity & Electronics circuits and electronic systems.pdf · bulb, sound in a radio, and...
17
Powerpoint Templates Page 1 Powerpoint Templates Electricity & Electronics St Oliver’s Community College
Transcript of Electricity & Electronics circuits and electronic systems.pdf · bulb, sound in a radio, and...
Powerpoint TemplatesPage 1
Powerpoint Templates
Electricity & Electronics St Oliver’s Community College
Powerpoint TemplatesPage 2
Electricity
• There are two main types of electricity:
1. Alternating current (AC)
0-220 volts (mains)
2. Direct current (DC)
0-24 volts (battery / transformer)
Powerpoint TemplatesPage 3
Electricity
Electrical energy is one of the most common and useful forms of energy. It is easily changed intoa variety of energy forms; light and heat in a bulb, sound in a radio, and movement in a motor.
In order that electrical energy can be tranformedinto other forms of energy we must create an electrical circuit.
A simple circuit would include a battery, switch and bulb.
Powerpoint TemplatesPage 5
Electric circuits:
• Electricity is the flow of charge around a circuit. It carries energy from the battery (or power supply) to components in the circuit, such as lamps and motors.
•
Electricity can only flow if there is a complete circuit from the power source through wires to components and back to the power source again.
Powerpoint TemplatesPage 6
Voltage and current:
A battery is a source of electrical energy – it provides the ‘pressure’ which causes electricity to flow. We measure this electrical pressure in volts, V. Voltage is also called potential difference.
The flow of electricity is called current and is measured in amps, A.
Powerpoint TemplatesPage 7
Resistance:
Anything which opposes the flow of current in a circuit is said to offer resistance. We measureresistance in ohms Ω.
Resistance wire, and components called resistorsare specially made to resist the flow of electricity. Connecting wire however, has a very, very low resistance – it allows electricity to flow freely.
Powerpoint TemplatesPage 8
Electronics
In this lesson we will learn about:
• Limit switches
• LEDs wired in series
• LEDs wired in parallel
• Wiring the circuit for the key cabinet clock project
Powerpoint TemplatesPage 11
Limit switches
Limit switches are used to detect when a moving part has reached it’s desired end point. The moving part presses down on the lever and activates the switch, which is used to turn off the lights when the door is closed.
Lever
Roller lever
Paddle lever
Powerpoint TemplatesPage 12
Limit switches
A limit switch has three connecting terminals
COM Common
NO Normally open
NC Normally closed
Powerpoint TemplatesPage 13
Limit switch
NC operation - If you connect the wires to the COM and NC terminals, the switch will be normally closed. When the lever is pressed, the switch will open and break the connection between the COM and NC terminals.
NO operation - If you connect the wires to the COM and NO terminals then the switch will be normally open, i.e. there will be no connection made between the COM and NO terminals, for as long as the limit switch is not activated. When the lever is pressed the switch will close and there will now be a connection between the COM and NO terminals.
Powerpoint TemplatesPage 17
Electronics
When reading a circuit diagram, you will see all the components as symbols. In the section you will learn about the electronics symbols and what they do.
