Re: Secondary Output Current

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: Steve Ward <steve.ward@xxxxxxxxx>

Many things can effect the apparent output current from a VTTC.  As 
you have noticed, its easy to stumble upon something that can change 
the output considerably.  Id hazzard a guess that the output current 
is probably in the 100mA range peak (this could be measured 
really...).  It is not deadly to contact it, due to the high 
frequency nature, but it can burn you internally (and externally) 
because there is a good bit of power there to heat the flesh!

Anyway, by changing the position of your feedback winding, you were 
changing the amount of feedback to the tube, probably such that the 
tube was in conduction for a greater portion of the cycle.

As to safety with the sparks, just keep your distance.  Its too easy 
to get too close to VTTCs.  The plate supply is much more deadly than 
the output sparks, be sure of that!

Steve Ward

On 9/15/05, Tesla list <<mailto:tesla@xxxxxxxxxx>tesla@xxxxxxxxxx> wrote:
Original poster: "Chris Fanjoy" 
<<mailto:zappyman@xxxxxxxxxxx>zappyman@xxxxxxxxxxx>

   What determines the current output of a VTTC secondary, anyway?
The reason I ask is becaused I discovered something last night while
working on my coil. I was finally starting to get some decent output,
but the secondary started arcing to the grid feedback winding. So I
moved the grid winding down the form, closer to the primary winding.
It seemed to solve the arcing problem, but I noticed something quite
remarkable; the output sparks were now very thick and hot - similar
to that of an oil burner transformer. Output current, by my guess,
would be around 20mA if not more - no doubt very deadly to come in
contact with!
   So does the spacing between the primary and grid windings, have
something to do with the current output? A thinner arc would be
preferable for looks, and no doubt somewhat safer to be working with.
   Thanks for any advice.