EnergyLab wrote:
This is quite interesting, a Tesla coil (of which I know very little about)
is being compared to a small radio antenna loop stick.
I believe the point was that there's [some] capacitive coupling between
the loose end and ground, which completes the apparently "open" circuit;
this is analogous to the situation with a Tesla coil.
The fact that there's [some] capacitive coupling there is certainly
undeniable; the /impedance/ of that coupling at 4 MHz is something else
again, and is an interesting question. With the short wire you've got,
I'd have expected the coupling to be far too small to account for the
observed effect -- and your original circuit had the juice going in
through the GATE on a MosFet which already puts a really tiny capacitor
in series with the input.
Regarding capacitive coupling in HF circuits in general, as an EE I knew
once said regarding proper ground returns, "If you don't provide a
ground return, Mother Nature will provide one for you -- but it may not
be one you like". (He was actually talking about computer data switch
design, which is a somewhat different arena...)
I would have thought that before one rests on taught (rather than factual
experience) that they would invest the time and a couple bucks to show
someone how stupid they are?
Eh hrm -- IMHO this is a delightful circuit whether or not it's got a
mundane explanation.
The issue isn't the couple bucks, it's the time to copy your setup
carefully enough to get the result you're seeing. The more info you
publish on the circuit, the better, as far as I'm concerned, because I'd
love to try to repro it eventually.
I think you mentioned the barium ferrite cores are "hard to obtain"; the
implication seemed to be that they're not currently being manufactured?
Do you just take apart lots of old transistor radios and hope to luck
out and find one, or does someone still sell the things?
But over the years I have learned on thing for
sure and that is that if I could get 100 people to duplicate anything I have
shown, it would be LUCK if even one of them (Duplicated) it. I would expect
to see everything from the cheap clip leads all over the kitchen table to
the full blown hand made circuit board and none worked, why, because no one
duplicated it, get it.
If you're faking this I'll eat my hat. (But that's just my personal
opinion.)
If you can put 1-4 volts into a baby antenna coil like this and pulse a 15W
light with a couple of watts at a 50% duty cycle, what this is not strange
when the primary is open? I have done the math, no I won't post it, do the
math and see or have we all come to mind experimentation only?
Don't ask me how I measure power, hint that it is wrong, how do you measure
power, I'll do it...
I'm not finding fault with your power measurements.
However, since you asked how "you measure power", where "you" is the
rest of the Vortex list, and I'm part of that "you", I'll tell you what
my initial attempts at measuring the power-in/power-out would be.
Please don't take this as condescension, nor as an attempt at saying you
don't already know more about how to do this than I do. I'm just saying
this is where /I/ will start if I ever get around to trying to repro
your circuit.
I'd use low-resistance series resistors, as you said you're already
doing (1 ohm, I think you said) and measure the voltage across them with
an oscilloscope, to get the current-in and current-out signals.
I'd attempt to measure the voltage across the the input (and output)
with a 100x scope probe, which has impedance ~ 100 Megohms. This pushes
the cost up above "a couple bucks", unfortunately, as I don't already
own a 100x probe and they're not cheap.
If that didn't work, because the impedance of the probe was still too
low and/or the wires were too long, I'd try to cobble up something with
a fet-input opamp on the board next to the LED as a voltage follower,
which would _hopefully_ have high enough impedance and short enough
wires to get a good reading without detuning the circuit so much the
effect vanished. I might need to spend some quality time with
datasheets to find one with the bandwidth to do the job; the TL086's
which I use for most of my "playing" are probably not capable of it.
I'd then feed the current and voltage signals to the two channels on a
scope and have it multiply them to get a power reading. (OK, this is
probably a naive or dumb approach for six reasons I haven't thought of,
but it's what I'd start with...)
My major initial interest would actually be in looking at the power
_leaving_ the signal generator -- I'd want to read the voltage and
current at the generator's end of the wires leading to the apparatus.
That is, of course, because I suspect the wires from the generator to
the apparatus of acting like an antenna -- but that's probably naive as
well; it's just where I'd like to start looking for the missing watts.
And, come to think of it, I might want to "float" the signal generator -
drive it from batteries or, if it wants AC, use an unplugged UPS or
something.
but you know what if the answer comes out not to match
your expectations, I will hear I did it wrong or I mis-read or I had this or
I had that. What? The vorts have been silent, why show me wrong, I can take
it.
It is so funny indeed, the last three videos I had planned on putting up are
covering a large strip light and a desk top lamp with over ten ultra-bright
whites in them. But gee whiz guys when someone sees no power source they
will go back to the beamed micro-wave crap.
I KNOW for sure why we have not arrived there yet, this is the show piece
example. It is against physics, against EE, LoT, well just about everything
so it does not exist RIGHT.
Please no one, run to the table with a handful of clip leads and some old
transformer ferrite to prove me wrong.
IMHO, as I already said, the effect is as real as houses; the only
argument should be over the cause.
Failure of someone else to repro doesn't prove you "wrong" or "dumb" or
a "phony". It just proves the effect is touchy and a little hard to
reproduce, which we already knew.
I think I have given all information
and photo's need to DUPLICATE it.
I hope so!
Oh! to the fellow vort that thinks I made a remark that applied to him on
how a Faraday cage must be grounded to earth.
IMHO the whole Faraday cage issue is a red herring and the ground wire
issue is all that twice over (two red herrings?).
a) Last I heard you could keep the ends of chicken legs from burning in
the microwave by wrapping foil around them. No need to ground those
foil "Faraday cages" on the legs, they block the signal just fine
ungrounded. What's magic about your situation that you can send radio
waves clear through an aluminum pie plate, even though the (VERY high
intensity) microwave beam in the oven can't make it through (far
thinner) aluminum foil? Nuthin', IMHO. (Here's another hint that the
ground wire may not be very relevant: Does the pie plate turn
transparent if you disconnect the ground wire, or does it still reflect
light the same way? Hmmm...)
b) If capacitive coupling between the free end and ground is really
playing a role here, as Bill Beatty speculates, then enclosing the whole
thing in a grounded cage will INCREASE that coupling and strengthen the
effect.
c) Unless you're intentionally irradiating the apparatus (and yourself)
with high power RF I don't see how the power density in the air could
contribute enough to do anything significant here, as I already observed.
In any case the cage and its ground wire are a side trip and a distraction.
If you, personally, want to verify that there isn't some unexpected
source of RF which is feeding your circuit, you can do something which
might be simpler: Just move into a different room in the house, or run
an extension cord outside and move the whole thing out of doors (and
enjoy the last of the pleasant fall weather while working on it).
You might also want to look up and around you while you're outside, to
check for any unexpected radio stations next door which you might have
overlooked. Short of something on that order turning up, I still don't
see how an external RF energy source could be playing any kind of role
in this system.
One last test for an external radio source: Turn off the signal
generator. What happens? Oh, the light goes out? Well then I think we
can scratch the "radio station" theory and forget about the Faraday cage.
The comment was not directed
to you, you were far from the only person that said something. Additionally
the RF people as I so said, insist that the ground I did make a point to
show is worthless. Well folks guess its up to you, I can't figure how to
make everyone happy.
I can't speak for "everyone" and what would make them happy. But I can
speak for myself:
Did you publish the values and part numbers for the circuit components
on your site? If you did (URL please?), that would make me very happy,
and I'll snapshot them for future reference, even if I can't find the
time to repro it this month.
Without component values and part numbers repro'ing it could take a lot
longer, as one runs down blind alleys with components that are "almost"
right.
This is just a rank out of total frustration and wondering about the void of
the dead field of science for the sake of science.
