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Re: [TCML] Isolating Transformer
My knowledge about electronics and frequency filters is limited to basic
stuff, so is it valid if I'm wondering if an off-the-shelf line filter does
do anything usefull in the first place?
Especially for larger coils with a resonant frequency around or below the
100kHz, since I think most filters start to be effective from the low Mhz
range. Doesn't anyone happen know usefull schematics for a DIY high
current, low-pass filter, which has an effective cutoff above mains
frequency?
As far as I've learned, an iron core in a transformer, is effective at
mains -low- frequencies and therefore shouldn't pass the higher
frequencies. But I've read higher frequencies are still passed, because of
inductive coupling between windings, which leaves me a bit confused. A bit
of explanation would shed some light on this matter.
Mark
www.youtube.com/user/748MJL
2013/4/26 Michael Gray <graymp89@xxxxxxxxx>
> So it doesn't make any functional difference?
>
>
> On 26 April 2013 14:11, Reverend Fuzzy <pastor@xxxxxxxxxxxxxxxxx> wrote:
>
> > I had a filter on each side of the transformer...probably
> > a little overkill, but better to err on the side of safe.
> >
> >
> > > -----Original Message-----
> > > From: tesla-bounces@xxxxxxxxxx [mailto:tesla-bounces@xxxxxxxxxx] On
> > Behalf Of Michael Gray
> > > Sent: April 26, 2013 2:13 AM
> > > To: Tesla Coil Mailing List
> > > Subject: Re: [TCML] Isolating Transformer
> > >
> > > Does it matter if I put my line filter in before or after the isolation
> > > transformer?
> > >
> > >
> > > On 13 April 2013 14:21, Michael Gray <graymp89@xxxxxxxxx> wrote:
> > >
> > > > Excellent. Nice to have found a use for it finally, assuming it
> > works...
> > > > haven't tried it yet!
> > > >
> > > > What's the primary reason for using them, generally? Safety? Or
> > > > RFI/surge suppression? Or both...
> > > >
> > > > On that note, how effective are they at suppressing surges,
> transients
> > > > etc.? I don't quite understand how voltage surges would be dampened
> > inside
> > > > the isolation transformer. What's actually limiting the output
> voltage?
> > > >
> > > >
> > > >
> > > >
> > > > On 12 April 2013 17:50, dave pierson <dave_p@xxxxxxxxxxx> wrote:
> > > >
> > > >>
> > > >>
> > > >> > Brian, what do you do with the output earthing? Do you use MOV's
> or
> > > >> > other filters?
> > > >> > I have a 1kW isolating transformer. The only time I have used it
> > live
> > > >> > was for a briefcase coil (1/2 low power NST for 3 inch sparks).
> > > >> > Interfered with the PA some distance away big time. I used a
> > > >> > counterpoise plus mains earth.
> > > >>
> > > >> Was the interference present with the isolation transformer?
> > > >>
> > > >> Isolation transformers come in (at least) two types.
> > > >> The usual/simple type is just a one/one transformer,
> > > >> two coils and core. This provides isolation for DC
> > > >> and LF AC, however stray capacity between windings/core
> > > >> can couple RF.
> > > >>
> > > >> A more elaborate type includes a 'screen' (internal
> > > >> Faraday Cage), which reduces the RF coupling. Sometimes,
> > > >> if i recall, referred to as an 'instrumentation
> > > >> transformer'?
> > > >>
> > > >> best
> > > >> dwp
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> > > >
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