- Jul 4, 2008
Terry filters don't protect the MMC though, I thought a primary strike can overvolt your MMC as well?
The same place I got the soft copper tubing at had some 4" pvc pipe (just not on display), so today I snagged two 22" long sections for $10 total. They couldn't cut it squarely though as their saw only cuts up to 3", so only one of the pieces has one square cut on it. I'll have to figure out how to fix the other should I ever need it as a coilform.
Yeah, there's no Home Depot or Lowes or equivalent up here, we have to make due with small businesses tailored to the normal needs of the community, which is mostly farmland. So if farmers or residential contractors don't need it, I can't get it locally.
That being said I have my new coilform and primary materials, and my spool of wire has been shipped. I'm not exactly looking forward to winding 1250-1500 turns by hand with no jig on such a large form, but hey, what can ya do? Lol. I don't have the tools (or money for them) to make a jig nor do I have the space to make it in. I don't even have a work bench, I use a 24" x 18" plastic folding table for all my projects. Sometimes living in an appartment sucks.
I'll worry about upgrading the NST/MMC later on, those are expensive upgrades. For now I have the daunting task of winding a huge (to me) secondary and making a base for the primary.
The MMC usually isn't a problem during a primary strike, due to the configuration of the circuit. The main victim is usually the transformer. MMC protection gap strongly discouraged by the Tesla Coiling community as it puts a great deal of stress on the MMC if it were to fire.
Quote from Mike Hammer
"Not sure how my name got into this discussion since Ive been
pretty much out of coiling for at least 4 or 5 years.
I still read the mailing list and still have the interest but
just dont have the time or resources anymore. Imagine the surprise
when my name jumps out at me during a quick scan of postings.
Im not sure why this person attached my name to this idea
of protecting a MMC via a spark gap. I was pretty much
out of coiling by the time MMCs became all the rage.
All of my caps were of the poly/foil type. Some flat
plate types and some rolled plate types.
To the best of my recollection I have never advocated placing
a spark gap directly across the primary cap. If such a gap
were to fire it would probably place a great deal of stress
on that cap from the very high currents involved.
I have strongly advocated safety gaps placed directly across
the transformer terminals as a fail safe of last resort as
well as a safety gap place in parallel with the main gap."