Re: [TCML] Taming the Beast: Inductive Ballast vs. Variac, PFC

["DC Cox" <resonance@xxxxxxxxxxxx>]

If I understand your question correctly, phasing is used with synchro RSGs.
I don't use any phasing with async.  I found around 400-450 pps gives a wild
spark, however, sometimes with Big Bruiser the sparks are slightly longer at
120 PPS.  Depends what you after is overall looks.

Dr. Resonance




On Tue, May 27, 2008 at 3:21 PM, Jeremy Scott <supertux1@xxxxxxxxx> wrote:

> I think I've seen some pictures of that on your big
> bruiser coil. It looks nice and is probably less prone
> to flinging stuff as the disc looks well supported on
> both ends. Good electrical isolation too.
>
> I'm sort of new to this ASRG thing. I've always fussed
> with the SRSG and getting it to phase properly and
> I've never been very good at that. I don't have a real
> good idea of how the ASRG works, but I think the
> concept is that you have enough power (pole pig) to
> charge the tank capacitor quickly for multiple firings
> in each AC cycle (>120). So as long as there are
> multiple electrode presentations, the phasing doesn't
> matter.
> Is that correct?
>
>
>
> --- DC Cox <resonance@xxxxxxxxxxxx> wrote:
>
> > If running a pole xmfr, gear down your treadmill
> > slightly with belts
> > and pulleys and pillow blocks, allowing for around
> > 450 pps for
> > excellent performance with good quenching.  Keep
> > your electrode dia at
> > least 3/8" (preferably 1/2") so the tips don't
> > overheat and spoil the
> > quenching action.
> >
> > Dr. Resonance
> >
> >
> >
> >
> > On 5/27/08, Jeremy Scott <supertux1@xxxxxxxxx>
> > wrote:
> > > I'm not sure what I'm going to make yet,  but an
> > ASRG
> > > is an option. I have one of those massive DC
> > treadmill
> > > motors plus the speed
> > > control for it. Could swing a 12" Garolite disc
> > easily
> > > :)
> > >
> > >
> > > --- "Lau, Gary" <Gary.Lau@xxxxxx> wrote:
> > >
> > >> Before going too much further, consider this.
> > >>
> > >> If using a .03uF cap with a 120BPS SRSG and a
> > 14.4kV
> > >> xfmr, your theoretical maximum power throughput
> > is:
> > >> 120BPS * .5*C*V^2 = 120 * .5 * .03E-6 *
> > >> (14,400*1.414)^2 = 746 Watts
> > >> You can use the biggest baddest pig available,
> > but
> > >> that cap and gap can't pull any more power than
> > >> above.  This is why pig-powered coils typically
> > use
> > >> async RSG's - to permit higher break rates and
> > pull
> > >> more power.
> > >>
> > >> Regards, Gary Lau
> > >> MA, USA
> > >>
> > >>
> > >>
> > >> > -----Original Message-----
> > >> > From: tesla-bounces@xxxxxxxxxx
> > >> [mailto:tesla-bounces@xxxxxxxxxx] On
> > >> > Behalf Of David Rieben
> > >> > Sent: Tuesday, May 27, 2008 8:55 AM
> > >> > To: Tesla Coil Mailing List
> > >> > Subject: Re: [TCML] Taming the Beast: Inductive
> > >> Ballast vs. Variac, PFC
> > >> >
> > >> > Hi Jeremy,
> > >> >
> > >> >
> > >> > ----- Original Message -----
> > >> > From: "Jeremy Scott" <supertux1@xxxxxxxxx>
> > >> >
> > >> > > That sounds interesting, and I may just take
> > you
> > >> up on
> > >> > > it. I have another option as well that I'd
> > like
> > >> to
> > >> > > explore too.
> > >> > >
> > >> > > I've got 225 amp lincoln arc welder
> > (240VAC@50A
> > >> input)
> > >> > > which I was going to use but I have some
> > safety
> > >> > > concerns. 1) What kind of current limiting
> > will
> > >> it
> > >> > > provide at 120V as opposed to 240V and 2)
> > Does
> > >> this
> > >> > > work if the welding leads are shorted vs.
> > not?
> > >> (The
> > >> > > switching mechanism temporarily breaks the
> > >> secondary
> > >> > > welding circuit and I am worried that this
> > will
> > >> > > translated to 'full blast' if I am running
> > the
> > >> coil
> > >> > > in between clicks.)
> > >> >
> > >> >
> > >> > I would assume that Ohm's law would apply and
> > that
> > >> > the arc welder would limit the current at 120
> > >> volts 4X
> > >> > what it does at 240 volts. Shorting the welding
> > >> leads
> > >> > allows for the maximum current throughput since
> > >> that's
> > >> > effectively what you are doing when you weld
> > with
> > >> it.
> > >> > Switching the tap selector switch will only
> > >> disconnect
> > >> > the power in between clicks, not run at full
> > >> blast. How-
> > >> > ever, you will find a label that states to NOT
> > >> switch
> > >> > the selector while it's under a load, as this
> > >> would quick-
> > >> > ly errode the switch contacts.
> > >> >
> > >> >
> > >> > > I may settle for it being adjustable only
> > when
> > >> the
> > >> > > main power is off, but I really like the idea
> > of
> > >> > > ramping up slowly by pulling a core.
> > >> >
> > >> >  This type of welder does not utilize the
> > sliding
> > >> core to
> > >> > adjust the current. There are simply multiple
> > >> taps.
> > >> >
> > >> >
> > >> > > Okay now that's interesting. I originally
> > wanted
> > >> a
> > >> > > small 5kV pole pig. But I settled for a PT as
> > an
> > >> > > intermediate stepping stone from the NST.
> > >> > >
> > >> > > I take it these things are much more robust
> > than
> > >> the
> > >> > > typical NST? (Fried my first one, like
> > everyone
> > >> else
> > >> > > :) ) Are RC protection circuits on the
> > secondary
> > >> a
> > >> > > good thing to have for it?
> > >> >
> > >> >
> > >> > Yes, PTs along with pigs are much more robust
> > than
> > >> > fragile NSTs and do not require RC circuit
> > >> protection
> > >> > although you can still use circuit protection,
> > if
> > >> desired.
> > >> > I believe the HV side of all 14.4 kV pigs and
> > PTs
> > >> are
> > >> > rated at 110 kV BIL, so they typically have no
> > >> problems
> > >> > standing up to the nasty kickbacks of a Tesla
> > tank
> > >> circuit.
> > >> >
> > >> >
> > >> > > I will probably not run that high a kVA on my
> > >> coils,
> > >> > > as I haven't sized the other components for
> > it.
> > >> (The
> > >> > > spark gap I'm planning on using is a 120bps
> > 1/4"
> > >> > > electrode SRSG 'propeller' style with
> > tungsten
> > >> rods
> > >> > > and the secondary is a 25"x6.5" form. Caps
> > are
> > >> going
> > >> > > to be MMC or a series of one, two or three
> > >> Maxwell
> > >> > > .03uf units.)
> > >> >
> > >> > >From your description of your proposed SRSG
> > >> design,
> > >> > I'd say that your coil should easily handle 4.2
> > >> kVA. Just
> > >> > make sure that you run enough strings of your
> > MMCs
> > >> (if
> > >> > you choose the MMC route) to handle the RMS
> > >> currents.
> > >> > I woud opt for a (4) sereised-parallel
> > >> configuration of those
> > >> > .03 uf, 35 kV Maxwells (for a total of .03 uFd
> > at
> > >> 70 kV)
> >
> === message truncated ===
>
>
>
>
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