8 Comments

I think the plumbing analogy is good to get people started, i.e. batteries, lights, switches. but once you get past household electricity level technology, it's best to abandon it and just make people learn/internalize volts, amps, watts.

That said, I frequently use engines as an analogy for "can I use this power supply?". Volts is like RPMs; it always needs to match. too fast and you'll damage the device. too slow, and it doesn't work. Amps is like /available/ torque. It doesn't matter if you hook up a tractor PTO or the motor from a shaver; if it has the specified torque /available/, the device can function. i.e. amps specification is just a floor. But again, the usefulness stops there. I would not try and use it to explain anything more complicated.

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Hey, I'm all in favor of tractor analogies!

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Amen!! Should be literally outlawed, IMO the analogy is barely applicable to secondary-school physics, yet I know it’s being taught to university undergraduates because it happened to meeeee. whyyyyy

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I have railed against this for years. When I was in charge of tutorial documentation for a technical product, I went so far as to say "all analogies are false." I challenged the authors to come up with better tutorial descriptions. E.g. following the example set by Hewlett Packard consumer products, such as the HP 200 LX

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But I was so proud of my inductor as paddlewheel analogy....

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I think of an inductor as a spinning flywheel. Pretty similar.

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And it can remotely spin nearby flywheels, which makes perfect sense

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Also, the plumbing analogy is not even that helpful since I am not a plumber! Why the indirection???

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