Re: Transformerless Tesla coil

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

Original poster: "Jolyon Vater Cox by way of Terry Fritz <twftesla-at-qwest-dot-net>" <jolyon-at-vatercox.freeserve.co.uk>

Antonio,
would this circuit work any better as a "balun" to allow a
centre-tapped HV transformer to be used to power either the
Transformerless or Capacitive Transformer coils?
Would it stop common-mode noise from damaging the transformer?

L1 = L2
L3 = L1/2
C2 = C3
C1 = 2*C2

                     +-----------to influence ring
                     |
                 +---+---+
                 |       |
                 L1     C2
                 |       |
   HV1----+--C1--+       +--L3--+
          |      |       |      |
        SG1      L2     C3      |
          |      |       |      |
   CT-+   +--+   +---+---+      |
      |   |  |       |          |
    GND SG2  GND    GND         |
          |                     |
   HV2----+---------------------+

I can see potential advantage in this -if it can be made to
work- as it would allowing the full power of the balanced HV supply
to be electrically connected to the single-ended resonator.

Jolyon.
----- Original Message -----
From: "Tesla list" <tesla-at-pupman-dot-com>
To: <tesla-at-pupman-dot-com>
Sent: Sunday, September 22, 2002 5:27 AM
Subject: Re: Transformerless Tesla coil


> Original poster: "Antonio Carlos M. de Queiroz by way of Terry Fritz
<twftesla-at-qwest-dot-net>" <acmq-at-compuland-dot-com.br>
>
> Tesla list wrote:
> >
> > Original poster: "Jolyon Vater Cox by way of Terry Fritz
> <twftesla-at-qwest-dot-net>" <jolyon-at-vatercox.freeserve.co.uk>
> >
> > Antonio,
> > with regard to powering either the directly -coupled transformerless- or
> > capacitive-transformer tesla coils from both sides of a centre
tap-grounded
> > HV transformer  as opposed to a single-end grounded HV supply
> > would making L1 a trifilar wound air-cored balun be any use in
fulfilling
> > this objective?
>
> This would fall in the problems of a magnifier and severe insulation
> problems. It's simpler to split C1 in two:
>
>                            (=====)
>                               |
>                               L2
>                               |
>    +  o------+--2C1--+--------+
>              o       |
>  PSU        gap      L1
>              o       |
>    -  o------+--2C1--+--------o Ground
>
> If C1 is an MMC, just split it in two, as the voltage over the two
> capacitors reduces to one half with this connection. The NST may not
> like much this connection, because when the gap fires one half of the
> RF oscillation appears in common mode at both its terminals.
>
> Antonio Carlos M. de Queiroz
>
>
>
>
>