Electricity and electronics - analogue and digital signals, including the characteristics of waves
This section looks at the differences between analogue and digital, which students should already have covered at KS4, but will probably need revising. Analogue signals are time-varying quantities which convey some sort of information, while digital signals are most commonly one of two values.
It also covers the characteristics of sinusoidal wave forms, most commonly seen in engineering with voltages, including:
- frequency
- amplitude
- periodic time
Students should already be aware of frequency and amplitude, but may not have been introduced to the term or equation for periodic time.
Analogue v Digital
Tutorial covering the basics of both digital and analog signals, including examples of each from an electronic engineering perspective. It also covers analogue and digital circuits, and components, as well as suggesting further reading and projects to aide understanding.
It could be given to students as either classwork or homework - to take notes from and then share their learning with the rest of their class - or by teachers who are looking for something to help with planning of the lesson.
Analogue and Digital
This activity, from the Institution of Engineering and Technology (IET), introduces students to the differences between analogue and digital communication. An analogue signal can be rendered useless by small amounts of interference, whereas a digital signal remains coherent.
Aimed at KS4 students, but handy as a recap for those in KS5 - it can be set as a reading homework or to help staff in planning of lessons.
Communications: Transmitting and Receiving Signals
Some of the information in this resource could be used for extension activities
A range of resources from SEP. It is based on two specially developed resources produced by SEP: the Optical Signal Transmission Set and the Analogue / Digital Transmission Set. The first of these uses visible light to demonstrate some basic principles of sending signals using electromagnetic radiation. The second set uses infrared radiation to demonstrate how carrier waves can be used for analogue and digital signals. Both sets can be used to model the way that radio waves are used to transmit information about audio signals. The downloadable resources include:
• student activities: zip files containing the activity sheets in PDF and editable Word formats.
• PowerPoint presentations: these contain a complete set of the images used in the booklet and activity sheets.
• further resources include sample sound files and guidance on using sound analysis software.
This requires the analogue/digital transmission set in order to get the most from it, but it's useful background reading for both staff and students alike.
The Wave Equation
Notes and examples of how to use the wave equation. An interactive page, useful for setting as homework or to check understanding in a lesson.
Episode 311: Speed, Frequency and Wavelength
These activities, from the Institute of Physics, consider how speed, frequency and wavelength are linked by the wave equation v = fλ . This is achieved by measuring frequency using an oscilloscope and measuring the velocity of sound in free air.
The activities include:
• worked example to deduce and use the wave equation
• exploring sound waves
• measuring frequency using a cathode ray oscilloscope
• measuring the speed of sound using a double beam oscilloscope
• investigating waveforms
and can be used as classwork or homework to support in class learning
Waveforms
An explaination of the basic characteristics that make up electrical waveforms.
Useful as background reading for students or to help prepare a lesson.
Covers sinusoidal waves and square waves, as well as other types of waveform that are not necessary.
Period of a Wave
An American site, with some useful information about the period of a wave, giving the definitions and formulae used in the topic.
Also shows the derivation of the sine wave period equation, along with some worked examples.
A useful resource for reading about the subject for teachers before planning lessons