RE: Metal Screws and Salt Water Caps

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

Original poster: "Lau, Gary by way of Terry Fritz <teslalist-at-qwest-dot-net>" <Gary.Lau-at-hp-dot-com>

In my experiment, I only looked to see how much the equivalent primary tank 
resistance in Ohms, i.e. losses, was affected by objects places near the 
primary.  No attempt to see actual operating performance differences were 
made.  See http://www.pupman-dot-com/listarchives/2000/November/msg00359.html.

Regards, Gary Lau
MA, USA



-----Original Message-----
From: Tesla list [mailto:tesla-at-pupman-dot-com]
Sent: Thursday, January 09, 2003 8:33 PM
To: tesla-at-pupman-dot-com
Subject: RE: Metal Screws and Salt Water Caps


Original poster: "Chris Roberts by way of Terry Fritz 
<teslalist-at-qwest-dot-net>" <quezacotl_14000000000000-at-yahoo-dot-com>


Gary,

How badly did the NST affect performance? Our NST is located really close
underneath the primary and we have been getting sub-par sparks from it.
(9kv, 120ma, only 20" sparks) Serves me right I guess for trying to make
the coil compact and good looking =).



   Tesla list <tesla-at-pupman-dot-com> wrote:
Original poster: "Lau, Gary by way of Terry Fritz "

There is no reason not to use metal screws unless they're so close to the
primary that they may cause a short between turns. Very large metal
objects are more problematic. A large metal-encased NST will contribute to
losses if it is closer than 6"-9" below a large primary coil (I did this
test with a 20" diameter primary, not sure how a mini coil-class primary
would behave).

Bleeder resistors are commonly used on MMC caps because shorting the end
terminals won't guarantee that individual caps are discharged. Since a SW
cap is not a series array, shorting the terminals WILL discharge the
cap. However, situations may arise where a charge could be left on a SW
cap (i.e. if the primary tap is loose), and SW caps are not that lossy that
the charge wil! l bleed off by itself. A series array of resistors would be
a wise addition.

Gary Lau
MA, USA

  >Original poster: "Centauri by way of Terry Fritz "

  >
  >Hello everyone,
  >
  >I'm assembling the base into which I will place all the components of my
  >coil, and I was wondering if I need to avoid using metal screws, bolts,
  >etc.. in certain places? Specifically, is it alright to use metal screws to
  >attach the legs. The head of the screw would be directly below the primary
  >coil with a separation of approx. 1". Is this acceptable? Also, what other
  >places should metal be avoided?
  >
  >Second, do I need resistor(s) across the terminals of my salt water bottle
  >cap or is it too lossy to matter? If I do, could I just wire a number of
  >small resistors in series?
  >
  >Thanks,
  >Alan



-Chris

"Learn from the mistakes of others. You won't live long enough to make all
of them yourself."-unknown