Re: Oudin Coil Design

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: "D.C. Cox" <resonance@xxxxxxxxxx>



Use micalex for the mica.

Dr. Resonance


> I am trying to duplicate a very old (horizontal) design Tesla coil, 
> which was featured in "High Frequency Apparatus" by Thomas Stanley 
> Curtis, 1916.  This was referred to as a Tesla coil because the 
> primary and secondary windings are in a horizontal 
> orientation.  while what we would normally describe as a Tesla Coil 
> (vertical form) was referred to as an Oudin Coil.  The coil used a 
> constructed  HV transformer rated 5000 volts, 100 ma. 3 glass plate 
> caps connected in parallel for a total of .03 mfd and straight 
> static gap.  Each half of the primary consists of 4 turns of 
> edge-wound 1/2-inch copper bar, 7-1/2 inch in ID.   Each secondary 
> is 6-inches in diameter, 8-inches long, with 400 turns of #30 DCC copper wire.
> Question:   The author does not stipulate if the primaries and 
> secondaries are wound in-phase or out of phase.  In other words if 
> the right-hand primary and secondary are wound clock-wise, should 
> the left-hand coils be wound counter-clock-wise?
> How can I duplicate an edge-wound primary.  Is some special jig or 
> fixture required?  Can this be done in a home shop?
> An optional Telefunken quenched gap is suggested.  This used copper 
> disks separated by mica washers approx. 6 inches OD and 4-1/2 inches ID.
> Can some one suggest a source of these washers?  Is there a modern 
> substitute for mica?
> Thanks,
> FJA