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

[Jeremy Scott <supertux1@xxxxxxxxx>]

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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