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Old 14th September 2018, 08:42
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BobClay United Kingdom BobClay is offline
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Join Date: Apr 2017
Location: Cornwall UK
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Further to my previous post I actually did present a few courses, evening courses for adults, at the Devon Community College where I worked.
These were usually science based but I did do one on basic desktop computer maintenance. I was surprised at how many takers there were. During the first lesson I was required to do some safety presentations, which really comprise of saying there are no dangerous voltages in a desktop computer other than in that grey box with a fan that the mains lead plugs into. If that goes wrong and you're not sure, unplug it, undo four screws ... and replace it.

However I did present a small lesson on what the meaning of voltage and current is. For people in general this requires a good visual demonstation. I used a car battery, a piece of mains fuse wire and a large pair of gloves. First off, wrap each end of the fuse wire around a nail and holding the nails with your gloves, short out the car battery. Very impressive visual sight of fuse wire glowing white hot and melting.
Then I'd tell them that the 12 volts provided by the car battery is the highest DC voltage you'll find in a computer, and it's quite harmless, please come up and stick the finger of one hand on one battery terminal, and the finger of your other hand on the other terminal.
Strangely, having seen the fuse wire all but vaporised, no-one volunteered. So I'd stick my fingers onto the battery terminals and pretend to get a powerful shock, then burst out laughing at their distress.
It probably didn't teach them much, but I got a laugh !!

"That's the safety bit over," I told them. "Twelve volts wont hurt you, but if that grey box with the mains plug isn't working, don't go inside it unless you're qualified. With regard to mains voltages remember that line from the film The Terminator: "It can't be bargained with. It can't be reasoned with. It doesn't feel pity, or remorse, or fear. And it absolutely will not stop... ever, until you are dead!"

Then I let them loose on a number of old classroom computers we had left over from a refit. (The basic internals of a desktop haven't changed much in terms of layout since I did this course in the early 2000's. The various bits have just got more powerful and faster, and the fans must be breeding in there … )

I think the course was successful because I was asked to do a couple more. But I abandoned the battery demonstration because heaving the bloody thing up the stairs almost did my back in.
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