Isn't the natural frequency for nervous system about 40 Hz? I remember
talking to a guy who was investigating the use of electromagnets to help
with healing, and if I remember correctly, he said it was at 40 Hz. I
can't remember to be honest, does anyone know?
I could see raising the frequency up a bit, maybe up to 80-100 Hz. That
would in fact drop down the size of power transformers but the conductor
size would be the same. You would really only save some on the amount of
iron. I don't think that would be enough frequency to increase the skin
effect that much (raise the conductor size). The main thing is steering
clear of the nervous system frequency or a harmonic thereof. In power
transformers, increasing frequency drops the core size but may increase
the conductor size due to the skin effect. However, the skin effect
doesn't really come into play except in the higher frequencies above
maybe 100 KHz or so I don't think. The reason being is, I've never seen
any increase in wire size for audio transformers, as compared to power
transformers. Most inverter/converter circuits run at 400-1200 Hz and
some more modern ones more than this. One must remember though that the
waveform is a square wave in inverters. This in turn changes the core
size somewhat from a sine wave (X 1.11).
Best & 73's
Will Matney
John Lawson wrote:
Usually I try to snip replies - but all this is relevant:
On Mon, 15 Nov 2004 Dennis12Amplify@aol.com wrote:
In a message dated 11/13/04 9:40:48 AM Central Standard Time,
dezrat1242@ispwest.com writes:
Which makes me wonder if it wouldn't be good to have our AC power
lines run at about 1000 Hz or so. No more shocks, no more accidental
electrocutions. The worst that could happen would be a burn.
Something to think about, eh?
I know the arguments against it - transmission loss being the most
significant - but someday when houses have their own little nuclear
generators and are "off the grid" it might be something to consider.
----------------------------------------------------------------------------
Actually, the power transmission would be much more efficient as the
transformers and capacitors could be made much smaller.
Regards,
Dennis O.
With all due respect, and purely out of regard for your personal
safety, I *STRONGLY* suggest that both you gentelmen immediately
suspend all involvement with these items until you gain a better
understanding of basic AC theory and practice!!
In the first place, the adverse physiological effects of voltage on
the human body is due mainly to currents above a certain threshold
across the chest cavity and heart structures, clamping and spasm of
muscles resulting in tearing of tissues, and nerve
damage/eradication. Then there are the burn phenomena, both resitive
and RF induced.
These come into play at various points and severities, depending on
the amount of current dropped by the body, the path taken by the
voltage, and the frequencies (from DC to RF) as well as the voltage,
and the duration of the exposure.
Y'all *really* oughta read up on some basic electrical and RF safety
- I'm sacred for you. I've lost friends in electrical accidents and
it's not the prettiest way to depart the planet.
As for power transmission being more efficient at higher line freqs:
look up "skin effect" and see how that tallies with your theory. High
frequencies travel more and more on the the surface of a conductor -
which is how microwaves use 'waveguide' (very basically). Many times
you will see big HF coils wound with tubing - no use having all that
copper if it'll never see the currents.
Aircraft used to use 400 Htz to cut down on the iron/copper wieght -
but the most modern ships are all going to DC busses as the gear gets
smaller and more integrated.
Please do get a btter idea of these safety issues before you find
out the hard way.
Cheers
John KB6SCO
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