Recent content by Allan Davis

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    Deriving capacitor and inductor models from Maxwell's eqs

    Have you tried deriving Ohm's law from Maxwells eq? No, can you give me a clue? I've been working with Maxwell's equations for a while (as a hobby :) actually I started by looking for applications of the FDM ), and never saw a derivation of the component models, and couldn't imagine how to...
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    Deriving capacitor and inductor models from Maxwell's eqs

    Positive ions instead of positrons? "A wire with a potential difference V across length L has constant E = V/L" This is the thing I've been missing, I've been viewing E fields as emanating as straight lines out from charged particles, not as snaking along a wire. But with the E field in the...
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    Deriving capacitor and inductor models from Maxwell's eqs

    I'm familiar with Maxwell's eqs as field equation, i.e. how they describe electromagnetic waves in space, but I don't see how to apply them to a wire, for example a wire connecting the two terminals of a capacitor. When the circuit is open there is an E field pulling between the electrons and...
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    Deriving capacitor and inductor models from Maxwell's eqs

    I'm sure the inductor model, i.e. vL(t) = iL'(t)*L follows without directly from Faraday's eq. But even there, with Faraday's equation we think of the changing magnetic field as inducing the voltage in the loop, where in the model it seems the other way around, that is, the voltage increases...
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    How does looping a wire make it an inductor?

    Yes, that's what I"m wondering about. So the looped wire has more inductance than the straight wire? How or why does looping the wire around an air core make it more efficient? Note: I found an inductance calculator and am studying the issue ! I see that looping the wire concentrates the...
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    How does looping a wire make it an inductor?

    Background: When electricity travels through a wire it creates a magnetic field around the wire. Creating the magnetic field requires energy, which is stored in the magnetic field. So, if we have a length L of wire and wrap it in a small loop of say 100 turns, it becomes an air core inductor...
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