[Prev][Next][Index][Thread]
Hey Bert (or anyone else) tell me something...
----------
From: Cabbott Sanders [SMTP:cabbott-at-cyberis-dot-net]
Sent: Monday, August 24, 1998 3:25 PM
To: Tesla List
Subject: Hey Bert (or anyone else) tell me something...
I have a 15 kva pig, and i got a 250 amp arc welder hooked in series with
it, up to 240 VAC. I have yet to feed this scarry arrangement any juice.
the dial is suppose to regulate the current.... right? the dials readings
start at 40A and go up to 250A. should i be disregarding this? i would think
the current limiting will be much different. how would i know what the
actual current is if i plug it in, with the dial at a minimum? I need a
current meter shunt thing right?
Tesla List wrote:
> ----------
> From: th3 mAst3r [SMTP:menthol-at-juno-dot-com]
> Sent: Sunday, August 23, 1998 4:53 PM
> To: tesla-at-pupman-dot-com
> Subject: Re: Primary field strength
>
> this post is a little old but my comment is at the bottom.
>
> On Thu, 20 Aug 1998 23:15:22 -0500 Tesla List <tesla-at-pupman-dot-com> writes:
> >
> >----------
> >From: Malcolm Watts [SMTP:MALCOLM-at-directorate.wnp.ac.nz]
> >Sent: Thursday, August 20, 1998 3:56 PM
> >To: Tesla List
> >Subject: Re: Primary field strength
> >
> >Hi Chris,
> >
> >> From: chris.swinson [SMTP:chris.swinson-at-zetnet.co.uk]
> >> Sent: Wednesday, August 19, 1998 8:58 AM
> >> To: Tesla List
> >> Subject: Re: Primary field strength
> >>
> >> Hi Malcolm & All.....
> >>
> >>
> >>
> >> >From: Malcolm Watts [SMTP:MALCOLM-at-directorate.wnp.ac.nz]
> >> >Sent: Tuesday, August 18, 1998 4:00 PM
> >> >To: Tesla List
> >> >Subject: Re: Primary field strength
> >> >
> >> >Hi Chris,
> >> >
> >> >> From: chris.swinson [SMTP:chris.swinson-at-zetnet.co.uk]
> >> >> Sent: Sunday, August 16, 1998 3:48 PM
> >> >> To: Tesla List
> >> >> Subject: Re: Primary field strength
> >> >>
> >> ><snip>
> >> >> so if the field is that big, I could easily make a 200"
> >secondary, as it
> >> >> appears the field is huge when the caps are included. Ok, I
> >could not do
> >> >> this as I only have 80" hight in my room. But you see what I'm
> >getting
> >> at.
> >> >>
> >> >> This was only 1 gap as well, If I used all 5 gaps , the field
> >would
> >> probably
> >> >> go 100's of yards away. So what stopping me from building a
> >bigger
> >> >> secondary ?
> >> >
> >> >The problem can summarised thus: You are transferring a fixed
> >amount
> >> >of energy from the primary cap to the secondary capacitance with
> >each
> >> >gap fire. Each gap fire is separate from every other. There is no
> >> >accumulation in the secondary with successive gap fires. The
> >> >capacitance of the secondary rises with its size.
> >> >
> >>
> >> I'm not 100% sure of what you getting at. Are you saying that if I
> >did
> >> build a 200" high seconday and ( theory ) had the same capacitance
> >as my 36"
> >> seconday, it would in fact give me a huge power increase ?
> >
> >It won't have the same capacitance - it will be a *lot* higher which
> >means output voltage will be a lot lower for a given primary energy.
> >
> >>
> >> >Since Vo = Vgap*SQRT(Cp/Cs), you can see what is happening to your
> >> >output voltage as your secondary gets larger. Taken to an extreme,
> >if
> >> >your secondary capacitance ends up being as big as the primary one,
> >> >secondary voltage only reaches that of the primary assuming no loss
> >> >in effecting the energy transfer.
> >> >
> >>
> >>
> >> Could you explain your calc a little better, Perhaps with a example
> >or 5.
> >
> >It is derived from Conservation of Energy.
> >
> > 0.5CpVp^2 = 0.5CsVs^2 where Vp = gap firing voltage
> >
> >=> Vp^2*Cp/Cs = Vs^2
> >
> >=> Vp*SQRT(Cp/Cs) = Vs
> >
> >In other words, you can't get more out than you put in and that
> >equality assumes no losses in transferring the energy from primary to
> >secondary. Note that it also works by Vs = Vp*SQRT(Ls/Lp) since
> >LsCs = LpCp (tuning requirement).
> >
> >Malcolm
> >
> >
> >
>
> why is LsCs = LpCp a tuning a requirement? does this mean most tesla
> coils are double tuned transformer circuits or am i getting things mixed
> up?
>
> thanks...
>
> ~m3nthol
>
> _____________________________________________________________________
> You don't need to buy Internet access to use free Internet e-mail.
> Get completely free e-mail from Juno at http://www.juno-dot-com
> Or call Juno at (800) 654-JUNO [654-5866]
--
Cabbott Sanders
Salem Oregon
Website: http://members.aol-dot-com/cabbotttt
Phone 503-390-8992
Cel 503-930-9173