RE: Higher Mains Frequency

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Mccauley, Daniel H by way of Terry Fritz <teslalist-at-qwest-dot-net>" <daniel.h.mccauley-at-lmco-dot-com>


There are a few problems.  Firstly, the length and conductor sizing needs to
be larger than that of a 60Hz system due to the increased reactance of the
higher frequency electrical system. (Not a big deal for small coils, but for
systems pushing 10-20kW+, considerable voltage drops could appear on the
lines if big fat conductors aren't used.  Also, at synchronous operation
(i.e. 400Hz), your talking about charging and discharging a capacitor 800
times per second.  It will take some pulse capacitor to handle that type of
PPS rates!!!  Serious heating going there if you are indeed charging the
capacitor from 0V up to the maximum AC voltage at those rates!

The concept indeed looks interesting, but why change an already perfectly
working system!!!  60Hz is more than readily available - why add the
complexities of a multi-kilowatt inverter system.

K.I.S.S. ! ! ! ! !

The Captain





 > Coilers,
 >
 > With the availability of large IGBTs and MOSFETs these days,
 > it seems to me
 > that one need not be constrained to running their PTs and DTs
 > with 60 (or
 > 50) Hz mains power.  One could build a multi-KW oscillator,
 > like those in an
 > UPS, and generate AC power at 120 (or 100) Hz, for example.
 > One would want
 > a sine-wave output, or at least a stepped approximation of a
 > sine wave.
 > This should be phase-locked to the mains frequency so SRSGs
 > powered from the
 > mains circuit still function OK (of course, doubling the
 > number of rotating
 > electrodes).  STSGs would be powered from the 120 Hz source.
 >
 >
 > This could prove interesting.  One could use lower
 > capacitance tank caps at
 > twice the BPS and still have the same power throughput.
 > Streamers probably
 > would be a bit longer at the higher BPS.  The spark gap and
 > streamer racket
 > would be more pleasing (240 Hz).  Power transformers,
 > especially MOTs that
 > barely have enough core, would be more efficient.  But eddy
 > current heating
 > would also be a little higher.  Etc.
 >
 > One could run their converter to output triple or quadruple the input
 > frequency for even more experimental fun & flexibility.
 >
 > Comments?
 >
 > --Steve Y.
 >
 >