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lcamtuf's avatar

It is probably worth noting that in the electronic parlance, the concepts of resistance may be sometimes used to refer to devices that dissipate energy in ways other than heat; from the circuit's perspective, all that matters is that the flow of current is impeded and that the phase shift is 0°.

In the same vein, reactance doesn't need to be a product of capacitors and inductors. Again, from a designer's point of view, the physics are unimportant; all that matters is that sine signals are impeded with a phase shift of +90° or -90°. In particular, there are some electromechanical devices that electronically, look like inductors or capacitors, even though the energy is not stored in electromagnetic fields.

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throwaway's avatar

Its nice to see people still look at explaining the more intuitive approach. I was stuck with learning electronics for ages because of the water pressure analogy, and needing to break out the Maxwell equations. Ironically, many books published prior to 1980 follow

the intuitive approach for quite a lot of subjects, compared to now that has you memorize equations that you don't know what or how they came about. The only reason I progressed past is from reading Heaviside's lectures from the turn of the century.

The local charity that sells books can be a goldmine.

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Vinay Hiremath's avatar

Thank you for this! Heads up the math formulas seem to be a bit messed up/wonky for me.

> In most circumstances, it’s what would cause a current to flow if you dropped a metal wrench across.

Also what are you referring to in this description of voltage? A wrench across what? Sorry I know this might be a dumb question.

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lcamtuf's avatar

The formulas are a Substack bug - reloading the page should fix it.

Across the points mentioned in the preceding sentence - sorry, updated the language to make it more clear.

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Vinay Hiremath's avatar

🙏🏾

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Matt Pogue's avatar

Long time IT guy, but my in-the-weeds electronics knowledge is sorely lacking! Loving both the introductory articles and the more advanced stuff, even when I'm struggling to understand it 😏 Passing along your links and compliments over at BlueSky as well.

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Ethan's avatar

Thanks for your concise write up's

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Yuri Desyatnik's avatar

There is also the neat reactance set of formulas.

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