How do coils REALLY work?
©2011 W. Beaty

  • How diodes REALLY work
  • How batteries REALLY work
  • How resistors REALLY work
  • How capacitors REALLY work

    Inductors. Coils of wire, what could be simpler?

    That famous "hollow pipes" fallacy defeats our visualization. All coils are never empty, they're always pre-filled with electricity. "Electricity flywheels"

    500-amp cable is a 1-turn coil, always. A 500T hoop-coil with 1amp is same thing? weird!

    animation of rotating barrel: coils are flywheels

    A shorted-out capacitor is against nature! It's abnormal, it's just not done. A shorted capacitor is not even a capacitor anymore. And... the same idea applies to coils. Coils are ALWAYS SHORTED OUT. Coils are closed loop components, always. In your mind, the component called "coil" should always have a shorting-bar across its terminals (just as inside your mind a capacitor is two completely separate plates.) A coil without a shorting-bar is profoundly against nature. It's not even an inductor anymore, not really. (If you embed this idea deep into your mind, you'll finally understand what inductors really are. Inductors are rotating wheels. But a coil with open terminals, that's not a coil at all; it's like a half of a wheel which never can turn.)

    much more weird: a coil isn't simply a long wire or a "heavy flywheel": because 2 turns gives 4X the effect of 1 turn

    "Dual" of capacitor, so look for coil-weirdness in capacitor info. "Violent discharge" of coil by opening a switch, causes giant voltage (coils are step-up power supplies)

    Coils are "charged" with energy, similar to capacitors. Both are energy storage devices. But for each charge injected in one end, another charge must leave the other wire. Coils don't store charge; don't store electrons (and neither do capacitors.)

    if a coil is a flywheel, then a transformer is just gears for performing step-up/stepdown

    transformer effect: if you jerk the electricity forward, it will drag the electricity of adjacent wires

    all AC/DC circuits are 1-turn coils. RF circuits not so much (antennas)

    bend long coil in a circle to form donut: torus coil with zero ext field

    Basic sinewave "oscillator" is a coil and capacitor: a flywheel going back and forth because it's connected to a spring.

    Weight of copper in the coil determines magnetism? WTF?!!!

    long coil is a waveguide (long dielectric rod is a waveguide)

    any straight piece of wire is a "coil," a segment of a 1T loop

    coils are antennas (loop antennas) just as capacitors are diplole antennas

    iron inside any coil SHOULD NOT be conductive, else it shields. Iron insulator? Magnetic only = ferrite

    Weird antenna: very long ferrite rod w/small coil in the center.

    WEIRD: domains flip one by one. If we change current, we hear random pulse-noise, "Barkhausen effect."

    Tesla's weird motor-coil: non-shielding toroid with three or more windings: two windings on same toroid fight each other, so magnet poles appear and spew field lines.

    Topology: coil wrapped around iron core. Iron wrapped around wire core

    Electromagnet: a magnet which can be turned on and off, or be flipped end-over-end a million times per second without actually moving.

    The science of conductivity is the science of coils, while caps are "insulator physics"

    Magnetic domains, iron is actually made of "powdered electromagnets." Waves of spin. closed loops get stronger. filaments of aligned spin. magnetism is the spin of vacuum charges, just as e-fields are polarized vacuum charges

    ideal coils are zero-ohms, even if thousands of turns. Always think of coils as superconductors, but w/added series res of the wire

    plug an (ideal) coil into an AC outlet, there is current BUT NO POWER, zero energy use. Imaginary power etc.


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