Re: eddy current with secondary coil

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

Original poster: "Malcolm Watts" <m.j.watts-at-massey.ac.nz> 

On 3 Oct 2003, at 12:11, Tesla list wrote:

 > Original poster: "chris swinson" <exxos-at-cps-games.co.uk>
 >
 > hi all,
 >
 > If the proximity effect of the secondary wires is causing higher eddy
 > currents within the wire, increasing reactance at high frequency, then it
 > would make sence to space the turns out on the secondary form so that more
 > energy will flow though the wire, which suggests higher output. Though this
 > can't be true since close turns is what is required ?
 >
 > Chris

Closewound is not a requirement. For a given wiregauge and form
length, you end up with a higher inductance and lower operating
frequency which is why most do it. You can think of a closewound coil
as being a spacewound one wound with thicker wire. From my
observations of running both types of secondary, spacewound is a
cheaper and lighter way to build a coil with about the same Q and
running frequency (i.e. the spacewound coil simply uses thinner wire
than the closewound one but uses the same winding pitch (turns/in).

Malcolm