Re: Explanation of K

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

Original poster: "Malcolm Watts by way of Terry Fritz <twftesla-at-qwest-dot-net>" <m.j.watts-at-massey.ac.nz>

HI Paul,

On 19 Dec 2001, at 8:13, Tesla list wrote:

> Original poster: "Paul Nicholson by way of Terry Fritz
<twftesla-at-qwest-dot-net>" <paul-at-abelian.demon.co.uk>
 
<snip>
> > There isn't much energy in the secondary in the early
> > stages of transfer so it would be helpful to know at
> > which point racing discharges occur.
> 
> Now there's a challenge!   Anybody know how to observe that?
> 
> My guess is they will occur within +/- a mode 3 quarter-cycle
> of the primary current zero crossings near the start of the
> beat or near a secondary current notch.
> 
> Perhaps if someone had a racing arc problem, and if they were
> to install a Q spoiling circuit tuned to mode 3 in series with
> the coil base connection, the mode 3 energy could be quickly 
> dumped into a resistance.  This might allow the variac to be
> cranked up another 10% or so before the problem occurs.
> 
> Alternatively, maybe a second primary, with a parallel cap to
> tune to mode 3 and a resistor across it too,  would have the
> same effect.
> 
> Perhaps those with long memories of coiling could say whether
> anyone has looked into these kind of things before?

Observations I've seen relayed to the list were pretty generalized. I 
would expect to see a discontinuity in the time domain trace when 
such an arc occurred. I'll make a mental note to look for it with the 
storage scope next time (whenever that will be) I induce a coil to do 
this. Then noting the system parameters and feeding them into the 
model, it should be possible to check for coincidences with the movie 
output. Noting where on the secondary  they occur will not be a 
challenge.  

Regards,
malcolm