Re: New Coil

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: "Malcolm Watts" <m.j.watts@xxxxxxxxxxxx>

On 28 Apr 2005, at 12:46, Tesla list wrote:

> Original poster: "Mike" <mike.marcum@xxxxxxxxxxxx>
>
> It was using a single 15/60 with a sync rotary gap. On a 0-120v variac
> gave about 5' sparks at full power for just under 2 min before there
> was a very loud bang and a mess. At first I thought it was just an old
> cap with its days numbered, so I tried another. It failed at just over
> 1-minute, but not as explosively (just made a not-as-loud bang and
> cracked the case, haven't got around to dissecting it yet). I haven't
> post pics of it to hot-streamer before, but could if I knew how. These
> things are tested to 40kvdc (with 35kv rating) and can't take too much
> more than that unlike mmc's. Runs fine on 12kv ones, but  if I used a
> 0-140 variac I wouldn't go over prob 130v in (13kV out). With 15 kV
> nst's you'd need at least 2 in series.
>
> Mike

In my opinion that experience brings into question the cap's
dielectric material and whether it was rated for the repetition rate
you were using it at. It also brings into question the firing angle
of the gap and whether it was firing on every half cycle (as in peak
voltage applied to the cap).

Malcolm

> ----- Original Message ----- From: "Tesla list" <tesla@xxxxxxxxxx> To:
> <tesla@xxxxxxxxxx> Sent: Thursday, April 28, 2005 12:44 PM Subject:
> Re: New Coil
>
>
> >Original poster: "Paul B. Brodie" <pbbrodie@xxxxxxxxxxxxx>
> >
> >Mike,
> >Are you saying that using one of the Maxwell .03 mF 35 kV pulse
> >discharge caps exploded using a 15 kV NST??!! How many mA's was the
> >NST? How long did it run before self destructing? I have a couple of
> >these caps and a 15 kV 30 mA NST. Thanks for any info you can
> >provide. I really don't need any explosions or such. Paul Think
> >Positive
> >
> >----- Original Message -----
> >From: "Tesla list" <<mailto:tesla@xxxxxxxxxx>tesla@xxxxxxxxxx>
> >To: <<mailto:tesla@xxxxxxxxxx>tesla@xxxxxxxxxx>
> >Sent: Wednesday, April 27, 2005 12:58 PM
> >Subject: Re: New Coil
> >
> > > Original poster: "Mike"
> ><<mailto:mike.marcum@xxxxxxxxxxxx>mike.marcum@xxxxxxxxxxxx>
> > >
> > > They work fine on 12kv nst's (about a dozen 3-5 min runs and still
> > > >
> > ticking
> > > in a bigger coil with more in series), explode after a few min on
> > 15kv > ones
> > > (makes a nice 12" blue/orange fireball tho with a big mess).
> > >
> > > Mike
> > > ----- Original Message ----- From: "Tesla list"
> ><<mailto:tesla@xxxxxxxxxx>tesla@xxxxxxxxxx>
> > > To: <<mailto:tesla@xxxxxxxxxx>tesla@xxxxxxxxxx>
> > > Sent: Tuesday, April 26, 2005 7:09 PM
> > > Subject: Re: New Coil
> > >
> > >
> > >>Original poster: <mailto:Esondrmn@xxxxxxx>Esondrmn@xxxxxxx
> > >>-snip-
> > >>
> > >>In a message dated 4/24/05 3:27:23 PM Pacific Daylight Time,
> > >>tesla@xxxxxxxxxx writes:
> > >>I plan on using my welder for current control and
> > >>either my two 1256's or my three 540 volt 30 amp
> > >>voltpac stack. I currently use my maxwells three deep,
> > >>but may only use them two deep for 75 nF 70 kV rating,
> > >>which is kinda small for a coil this size. I'm afraid
> > >>to use them as 300 nF 35 kV, as this seems to be too
> > >>close to the edge. I have no idea how rough a life
> > >>these guys had before I got them.
> > >>
> > >>Adam
> > >>
> > >>Adam,
> > >>
> > >>I have a couple of those Maxwell caps also, and as you, have been
> > >>concerned about using only one and have always used the two in
> > >>series. I have read where lots of folks on this list have the same
> > >>caps.  Is >>anyone only using them individually, or multiple in
> > >>parallel?  If so, with what power supply?  I would feel ok at say
> > >>10 kv but both of my coils use a >>15 kv supply and I have just
> > >>been chicken to find out what kind of voltage they can really
> > >>take.
> > >>
> > >>Ed Sonderman
> > >>
> > >>
> > >
> > >
> > >
> > >
> >
> >
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