Re: EM only coil?

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

Original poster: "Sean Taylor by way of Terry Fritz <twftesla-at-qwest-dot-net>" <taylorss-at-rose-hulman.edu>

Hi Josh,
 > I want to construct a tesla coil that is not about sparks but about EM
field.

Strictly speaking, the secondary of a TC isn't need if all you want to do is
create an E-field and B-field, the discharges into the primary do that,
which causes the induced voltage in the secondary in a conventional TC.
However, if you remove the secondary, most of the energy stays in the
primary circuit, and can damage components such as overvoltage on the NST
and/or cap(s).  You would have to seriously derate the ratings of the cap,
by how much I don't know, I'm sure you'll get many more responses.
The reason more energy is radiated in the form of a field when the coil is
out of tune is that the secondary is not absorbing all the energy and
creating sparks, but the same energy is being put into the tank circuit.
The same thing will occur for a TC system with an oversized toroid/too low
input power.  There will be no breakout, and the energy will be radiated by
the E-field/B-field.
Hope that helps some, sorry if it didn't make a lot of sense, I just got
done taking the GRE about an hour ago, so my thoughts aren't exactly
entirely coherent right now :-)

Sean Taylor