INDUCTORS
How do coils REALLY work?
[NOTES FOR UNWRITTEN ARTICLE]
©2011 W. Beaty
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.
