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RE: Request for help with air core transformer/power transfer system



Original poster: Harvey Norris <harvich@xxxxxxxxx>


--- Tesla list <tesla@xxxxxxxxxx> wrote: > -----Original Message----- > > From: Tesla list [mailto:tesla@xxxxxxxxxx] > > Sent: Monday, December 06, 2004 8:01 PM > > To: tesla@xxxxxxxxxx > > Subject: OT: Request for help with air core > transformer/power > > transfer system > > > > > > Original poster: David Speck > <dave@xxxxxxxxxxxxxxxx> > > > > List, > > I know this isn't directly TC related, but I > hoped someone with more > > transformer theory experience that I have might > lend a hand, > > with Terry's > > indulgence. Please feel free to respond > privately. > > > > ->Sound enough like electricity transmission > without wires ;o)) But > > respond direct if not really related to Tesla > coils) - T. <- > > > > I'd like to transmit about 6 volts AC at 60 Hz > and 250 mA > > through a glass > > plate about 1/4" thick without drilling a hole in > the glass, > > and without > > making any really esoteric circuitry like a high > frequency drive > > circuit. I achieve almost perfect coupling with spirals using wide margin width wire so that the spirals encompass internal capacity. By perfect coupling, this implies a reduction of impedance to the source; when the recieving instrument is in proximity. As such the real question is simple, place a set of spirals between a glass plate, and record the inductance of the source, where both the open circuit and closed circiut configurations of the secondary are noted. If the impedance of the source, neglecting resistive losses which are ordinarily insignificant in my case of coil transmissions: if that impedance doubles then you have perfect mutual coupling with identical L sets of spirals. At a 6 VAC @ 60 HZ measurement, the proposition shows that such a "source frequency" inductance change measurement between spiral sets is practically impossible, and typically such a determination of mutual inductance by classic methods states that the difference between those two reactive states dictates the mutual induction between the systems. The situation you are here describing is easily possible by several considerations. The first loophole beomes the fact that L1 and L2 as proximity reactance measurements in fact can have little to do with those same measurements made when each L quantity is given a C quantity to resonate at the source frequency resonance. In other words what looks like almost independent magnetic action of two components when measured in the reactive state, can exhibit far more mutual inductance states when each L is given a C value to resonate at the source frequency that now delivers a whole new set of values is taken with current delivery measurements on both input and output comparisons of secondary open and closed situations. As such the action of Of L2C2 as secondary can influence the choice of the C1 value on the tuned segment on the primary L1C1, whose C1 value is first tuned to the reaction proximity of condition L2C2 circuit/ In the case of mutual inductance at resonance however it is only mutual when the components share flux change. As such a square multiturn coil can induce more flux change on a adjacent spiral, then the reverse situation will allow. and because of this, the normal determination of mutual induction effects is invalidated by comparing the unity to opposition measurements in the reactive states, which is the normal parameter noted as L1L2 interactions, which can be signicantly greater or different between each other when paired as L1C1/L2C2 interactions. To secure a high inductance L1C1 primary at 60 hz would be a great problem, but probably not nearly as bad as the problem involved wiith matching the C2 value to the low inductance spiral of the receiving instrument. The key to considering the validity of air core inductive systems at source frequency is the consideration that AC alternators can easily deliver frequencies in the 500 hz range or beyond, and then the sensible pairings of L1C1/L2C2 values can be made. In this described situation of paired spirals between glass, @ 480 hz with resonant spirals matched to the frequency transmission of the alternator, power transmission between the components would only be reduced according to the flux leakage afforded by the glass, maybe a 80% power loss, according to my guess. ()

 An eight fold increase of frequency to 480 hz makes
the inductive reactance go up eight times by X(L)= 2
pi*F*L, but the capacitive reactance X(C)= 1/[2pi*F*C]
means the inverse C value for matching reactance goes
down 64 fold in comparison to original demands at 60
hz: thus effectively enabling sensibly tuned L1C1/L2C2
spiral arrangements. In a 0ne inch layer of of 9 inch
diameter, 2 inch ID spiral winds comprising four
layered spiral winds of some 120 winds, the value of
matching capacity of the 2.3 mh spirals was shown to
be ~7 ohms, some 44 uf of capacity. Such adjacent
spiral groups as adjacent sets were shown to have a
high mutual inductance, MERELY ON THE REACTIVE
READINGS ALONE! What this means is that according to
starting understandings the inductive reactance is
first measured at 7 ohms, but because the spirals
share almost complete coupling of flux change, the
adjacent presensce of the shorted secondary L2,
decreases the impedance measurement of L1 to be almost
half that of the former measurement, thus showing good
coupling in the reactive state. Thus based on the
readings of the new reactive state, each capacity of
the tuned L1C1/L2C2 combination would be also doubled
on first approximation, to comparative readings made
in isolation. That would be how things are tuned from
the data of interactions obtained from the reactive
state of mutual induction, which also predicts the
correct capacities to be used in the resonance,
however in some cases of resonance the mutual
inductance measured in the reactive state is different
from its resonant case. Thus a second approximation of
tuned L1C1/L2C2 values is in order when the mutual
cou-pling is not as great, to see whether the change
in both C values simultaneously to a higher value
according to an increased lenz law effect at resonance
comes into play.

Power transmission is easily possible through glass at
alternator frequencies, provided a correct match of LC
spirals is negotiated.
Sincerely HDN