Re: Successful SSTC Audio Modulation - SWEET!

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Original poster: "WIZZARD . by way of Terry Fritz <teslalist-at-qwest-dot-net>" <pbobyk-at-hotmail-dot-com>

I would love to know how this is done.
The effect of a Tesla coil is stunning.
Modulating it's output to audio is the "Catz Ass"
Pardon the terminology.

WIZZARD ( in training )


>From: "Tesla list" <tesla-at-pupman-dot-com>
>To: tesla-at-pupman-dot-com
>Subject: Re: Successful SSTC Audio Modulation - SWEET!
>Date: Thu, 29 May 2003 20:00:39 -0600
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>Original poster: "S Gaeta by way of Terry Fritz <teslalist-at-qwest-dot-net>" 
><sgtporky-at-prodigy-dot-net>
>
>Congratulations Dan!
>
>I noticed the same thing with my tube coil. When you draw an arc, the hiss
>from the corona wind goes away, and the audio has a purer sound from the hot
>plasma.
>
>Sorry that you lost a bridge rectifier, but I'll bet it was worth it now! My
>tube coil ate a mica cap in the beginning.
>
>Cheers,
>Sue
>
>----- Original Message -----
>From: "Tesla list" <tesla-at-pupman-dot-com>
>To: <tesla-at-pupman-dot-com>
>Sent: Thursday, May 29, 2003 9:46 AM
>Subject: Successful SSTC Audio Modulation - SWEET!
>
>
> > Original poster: "by way of Terry Fritz <teslalist-at-qwest-dot-net>"
><dhmccauley-at-spacecatlighting-dot-com>
> >
> > After a day of extreme frustration (yesterday gate drive problems) and a
> > simple re-design of my gate drive topology, i finally got my SSTC to run
> > from the push-pull outputs from the
> > TL494.  So now, I have 25% on-side1, 25% deadtime, 25% on-side2, 25%
> > deadtime.  This is required as operating in CW mode consumes mucho power,
>so
> > by running the coil
> > this way, you can reduce total output power and improve reliability of the
> > h-bridge switch.
> >
> > Audio was provided by a CD player (high impedance output) and fed into the
> > deadtime comparator pin of the TL494 through an 0.1uF capacitor.
> >
> > Audio output was very clear and almost zero noise otherwise from other
> > harmonics in the arcs.  Very impressive, similar to Sue Gaeta's high side
> > modulation audio quality on her 811A
> > VTTC.  Also, with fan cooling, the heatsinks and FETs never even really
>get
> > warm.
> >
> > One note to add, is that to improve audio quality, it is necessary to
> > draw-out a continuous white flaming arc from the toroid.  This can be done
> > by any metallic object and permanently set at about
> > a 2-3 inch gap depending on output power levels.  The result is stunning
> > audio.  (at least stunning when considering its coming from a hot flaming
> > multi-kilovolt arc ! ! !)
> >
> > Also, volume control can be provided by adjusting this discharge gap
> > distance.  To get really loud audio, just try to stretch the arc as long
>as
> > possible.  I guess this provides much more heating of the air and
>therefore
> > more volume.
> >
> > Awesome!
> >
> > The Captain
> >