Going back to school. Waves and modulation for 9-11 year olds. Wish me luck!

Описание: It's Science Week and parents have been asked if they can come in to primary school to do a science or technology lesson. So we're going to be introducing oscilloscopes, waves, modulation, analogue/digital, optical data and 75 years of gadgets.

Update: This was done with the first class (year 5) on 10.03.26. The only technical difficulties I had were 1: We lost the mains cable for the Sanyo boombox so they didn't get to play a cassette on that, and 2: The FM modulation depth was too high, I couldn't find how to adjust it quickly, so the sounds worked but didn't really sound like sirens which is what I had hoped for. The children really enjoyed it, I could tell that some of them were certainly grasping the concepts. Their favourite "gadget" from my collection was probably the Digital Betacam camera, they were stunned to hear that when new it cost as much as a house. They also really enjoyed finding how high and how low they could hear.

See and hear waves:
Briefly explain what an oscilloscope does and show it on screen.
Let the children make some sounds, whistle, ring a bell, and see the waveforms on a small battery operated oscilloscope with a microphone
Use a signal generator and speaker to make some frequencies, try limits of human hearing with the speaker and also headphones connected to a tablet.
Let some children try to hear very low and high frequencies on the headphones (but maybe not the whole class, could take too long).
Shown how waves can be different shapes.

Wobble the waves:
Show Amplitude and frequency modulation, briefly mention it's how radios work.
Make some interesting sounds with a dual frequency generator and speaker. (Bleeps, different siren sounds etc.)
See if the children can start to predict what a waveform might sound like before we make the noise on the speaker.

Analogue and digital:
Briefly explain the difference between older analogue devices and modern digital ones.
Show some props (old 'phone, old radio, cassette tapes, CD, DVD, modern devices)

Modulating light:
Show how we can send information along a fibre. Let a pair of volunteers send a message along a fibre with a torch. (Note, using plastic fibre not glass, for safety reasons)
Mention Wildanet in Yealmpton. Show the purple plastic straw they have installed in the ground.

75 years of gadgets:
Use a timeline, work with the children to put some props into their decades and have a think about which are analogue and which are digital.

10 x props:
1951 radio (wireless set)
1961 transistor radio
1971 telephone (trimphone)
1982 radio/cassette
1979 Betamax video cassette recorder
1983 Compact Disc CD
1999 DVD
2000 Sky Sports Television camera (Digital Betacam)
2010 iPod gen 4
2024 Wildanet fibre

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Music “Let It Run” with permission, copyright Cristie/MacFarlane.

Sorry I do not offer an audio or video equipment repair service.

00:00 Introduction and slides
11:56 Look at some of the gadgets (props)
17:00 Microphone to pocket oscilloscope via Tascam DR100MKII
19:29 Arbitrary Waveform Generator to speaker and oscilloscope
28:12 Conclusion
31:41 JVC miniDV camcorders are terrible