Re: Permanent magnet Tesla coil

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: Ed Phillips <evp@xxxxxxxxxxx>

"Original poster: "Mike" <mike.marcum@xxxxxxxxxxxx>

Dis some reading on that. First question that comes to mind is why
they are so big given the frequency (aka: 60Hz generators are 6x+
heavier than 400Hz versions of the same power). I once had a 200kVA
400Hz generator that "only " weighed 7000lbs (spun at 2400 rpm by the
spec plate irrc). Seems like the 50kHz version of that would weigh
100lbs instead of 100 tons."

	Answer is easy.  The amount of iron (and hence copper) required in an
iron core is INVERSELY proportional to the frequency, whether the
iron-cored device be a motor, transformer, generator, solenoid, or
what.  So, as a rule of thumb, one would expect the 60 Hz generator to
weight of the order of (400/60) or about seven times as much as a 400 Hz
generator.  Your figure of 6+ is to be expected.

Ed