Ricks coil - was Fast ground rod

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

Original poster: "S & J Young by way of Terry Fritz <twftesla-at-qwest-dot-net>" <youngs-at-konnections-dot-net>

Rick,

The output of your supply will be 21 KV only under no-load conditions.  When
you start extracting power out of it, the voltage will drop toward 15 KV.
There are formulas to calculate output voltage vs load and filter cap size,
but you will probably prefer to actually measure the output voltage as you
crank up the BPS.

If you measure output current, be sure to do it between the filter cap and
power supply, not between the filter cap and gap which will have huge
pulses.

I recommend the Deano SPDT hookup - works much better.

--Steve
----- Original Message -----
From: "Tesla list" <tesla-at-pupman-dot-com>
To: <tesla-at-pupman-dot-com>
Sent: Thursday, July 26, 2001 7:47 AM
Subject: Re: Fast ground rod


> Original poster: "Rick W by way of Terry Fritz <twftesla-at-qwest-dot-net>"
<rickwilliams404-at-earthlink-dot-net>
>
> Well hey list,
>
> Rick here. Yes, I have a 12.5 inch secondary, 47" coil length. The project
> is still under construction. Projected tank cap is 80nF (might go 100nF) ,
> primary about 16 turns of 1/4" tubing spaced 1/4" apart, 29" outside
> diameter. (Couple of extra turns for tuning) Resonant freq is just a
little
> under 50K (1/4 wave). Going for 5 NSTs, 15Kv 30ma each. But I'm going DC
> with this project. Shooting for about 100 BPS as an arbitrary starting
> point. The filter cap for the supply is 12 times the value of the tank
cap.
> Also the DC filtered output is 1.414 times the AC input, 15Kv times 1.414
=
> 21KvDC.
>
> During initial design a limiting resistor was employed to soften the shock
> of charging the tank cap through the SPDT RSG. The was calculated to allow
> the tank cap to be charged after 5 time constants, about 1 millisec. After
> charging there would be very little demand, if any at all, of current from
> the filter cap.
>
> So, 100 BPS figures out to 1 pulse per 10 millsecs leaving 9 milliseconds
> for the filter cap to recoup the energy expended. There will be a voltage
to
> which the filter cap will settle out to as per the input current. That
> voltage should be well over 15Kv anyway (there will be ripple
> *understatement*). Once the tank cap charges the energy stored there is
the
> energy that's pumped into the system, the supply current is then out of
the
> picture and can then be used to begin recharging the filter cap. At 80 nF
> (maybe 100nF) charged to over 15Kv there should be plenty of energy to
power
> the coil.
>
> The beauty of DC is I'll be able to vary BPS a lot with no concern about
> crossover and sync problems.
>
> But now there may be new light on the DC coil horizon concern how the SPDT
> RSG is connected in the circuit. In the meantime I'll continue
construction
> of the DC supply. Hope to have the supply finished at the end of next
week.
>
> Rick Williams
> Salt Lake City
>
>
> ----- Original Message -----
> From: Tesla list <tesla-at-pupman-dot-com>
> To: <tesla-at-pupman-dot-com>
> Sent: Wednesday, July 25, 2001 9:10 PM
> Subject: RE: Fast ground rod
>
>
> > Original poster: "Loudner, Godfrey by way of Terry Fritz
> <twftesla-at-qwest-dot-net>" <gloudner-at-SINTE.EDU>
> >
> > Hi all
> >
> > Well I guess I should have wrote that it was my dictum. I would hate to
> > search the archives for the listings which led me to form this dictum.
It
> > was simply a series of listings which seemed to be saying that big coils
> > needed big power supplies. I was certainly a believer. After getting a
10
> > inch diameter secondary form Marc Metlicka and seeing the huge size of
the
> > form, my impression was complete. I decided that I would need my
> 14.4kV/5kVA
> > pole pig for the power supply. I am far from completing my pig system,
but
> I
> > am thinking about Marc's suggestion of using a triggered gap. My adult
> > experience with tesla coils is limited to diameters not exceeding four
> > inches. A was aware of Terry's big research coil using a 15kV/60mA NST,
> but
> > I just assumed that he did not want long streamers because they would
get
> in
> > the way of making measurements. So I was very surprised when I saw
Terry's
> > big coil in action.
> >
> > If you look at John's formula for streamer length, it says that streamer
> > length is only a function of wallplug watts. Yes sir,
> > that's what it says. When someone off the list (now on the list) told me
> > that he had a 12 inch diameter secondary, I told him that he had to load
> up
> > on NSTs or get a pig. Rick got five 15kV/30mA NSTs, but he did say that
he
> > wanted to start off with over 100mA. Well I always have said, "how could
> you
> > be so wrong about something that you thought was so right."
> >
> > Godfrey Loudner
> >
> > > -----Original Message-----
> > > From: Tesla list [SMTP:tesla-at-pupman-dot-com]
> > > Sent: Wednesday, July 25, 2001 4:13 PM
> > > To: tesla-at-pupman-dot-com
> > > Subject: Re: Fast ground rod
> > >
> > > Original poster: "Malcolm Watts by way of Terry Fritz
> > > <twftesla-at-qwest-dot-net>" <m.j.watts-at-massey.ac.nz>
> > >
> > > Hi all,
> > >
> > > On 25 Jul 01, at 11:28, Tesla list wrote:
> > >
> > > > Original poster: "by way of Terry Fritz <twftesla-at-qwest-dot-net>"
> > > <FutureT-at-aol-dot-com>
> > > >
> > > > In a message dated 7/25/01 9:43:29 AM Eastern Daylight Time,
> > > tesla-at-pupman-dot-com
> > > > writes:
> > > >
> > > > > Original poster: "Loudner, Godfrey by way of Terry Fritz
> > > > <twftesla-at-qwest-dot-net>"
> > > > >  <gloudner-at-SINTE.EDU>
> > > > >
> > > > >  Hello Terry
> > > > >
> > > > >  When someone comes on the list stating that they are going to use
a
> > > > >  15kV/60mA NST as a power supply for a tesla coil having a
diameter
> of
> > > about
> > > > >  10 inches, the usual advice is to get a pig or equivalent because
> you
> > > won't
> > > > >  have enough power to even cause the toroid to breakout.
> > > >
> > > > Godfrey, all,
> > > >
> > > > I wonder how that view developed?  I often use a 6" x 24" secondary
> > > > with a 12/30 NST with excellent results, so a 10" dia coil for a
15/60
> > > > would seem very reasonable to me.
> > > >
> > > > John Freau
> > > > --
> > > >
> > > > Your coil is
> > > > >  certainly a counterexample to such a dictum. Can you say
something
> > > about
> > > > why
> > > > >  your large diameter coil is working so well with a small power
> > > supply.
> > > > >
> > > > >  Godfrey Loudner
> > >
> > > I too wonder where that idea came from. As Bert Pool can attest, the
> > > transformer I use for my 10" coil is smaller than most NSTs of any
> > > rating. It was photographed last year throwing sparks over 5' in
> > > length with an oblate topload measuring 10" thick with a 19"
> > > diameter. The bottom line is: ability to breakout is dependent on
> > > primary energy and rep rate takes over from there. The capacitive
> > > loading for the transformer defeats the faceplate ratings so you can
> > > basically suck what you like from it within the limitations its
> > > leakage/ballast inductance will allow for the capacitor being used.
> > >
> > > Malcolm
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> >
> >
> >
>
>
>