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DC suppl;y

Subject: 
          DC supply
      Date: 
           Mon, 31 Mar 1997 09:25:30 -0500
      From: 
           chuck seguin <seguinc-at-algonquinc.on.ca>
        To: 
           Tesla List <tesla-at-pupman-dot-com>
References: 
           1


Tesla List wrote:
> 
> Subject:
>         Re: DC supply
>   Date:
>         Sun, 30 Mar 1997 03:10:21 -0700
>   From:
>         "DR.RESONANCE" <DR.RESONANCE-at-next-wave-dot-net>
>     To:
>         "Tesla List" <tesla-at-pupman-dot-com>
> 
> To: Chuck Seguin
> 
> The DC laser power supply does not have sufficient current to adequately
> drive even a small size Tesla oscillator.  A neon sign transformer such
> as
> a 12 KV 60 ma unit would do a much better job.
> 
> A synchronous rotary spark gap is essential a high speed switch that is
> synchronized to the 60 HZ AC line that is charging the Tesla oscillator
> capacitors.  As an example a salient pole synchronous 1800 RPM motor
> used
> with 4 rotatating electrodes would allow you to fire at the peak of the
> AC
> waveform.  Actually best point is usually 10-15 degrees beyond peak. The
> rotor is loosened and rotor is manually adjusted on the motor drive
> shaft
> -- system is run again and an O-scope checks to see if you are firing on
> the peak -- if not, again more adjustment of the rotor on the drive
> shaft
> until your RSG electrodes are in alignment with the poles of the drive
> motor.
> 
> While synchro types of RSG's (rotary spark gap) do produce much higher
> peak
> current in the secondary discharge they do not usually produce longer
> sparks than a non-synchro RSG.  The non-synchro gap cap effectively
> fires
> more times per half cycle which in turn pumps the tremendous ionic field
> above the secondary HV terminal and the sparks actually "grow" outward
> to
> produce longer discharges.  We must also assume your power supply is
> capable of re-charging the HV capacitors quickly (faster than 30
> milliseconds).  This is usually the case in all but the most strained
> power
> supply configurations.
> 
>  Running a Tesla coil on DC is possible but the quenching problems
> become
> more serious.  DC does not quench as well as AC because the waveform is
> not
> reversing -- this reversing helps the quenching action somewhat.
> 
> Hopes this helps out -- have fun with your power supply.
> 
> DR.RESONANCE-at-next-wave-dot-net
> 
> ----------
> > From: Tesla List <tesla-at-pupman-dot-com>
> > To: tesla-at-poodle.pupman-dot-com
> > Subject: DC supply
> > Date: Thursday,March 27,1997 9:49 PM
> >
> > Subject:
> >         DC supply
> >   Date:
> >         Thu, 27 Mar 1997 09:58:10 -0500
> >   From:
> >         chuck seguin <seguinc-at-algonquinc.on.ca>
> >     To:
> >         Tesla List <tesla-at-pupman-dot-com>
> >
> >
> > Good morning everyone,
> >
> > Here is a question that puzzles me.
> >
> > I have aquired a great XFMR from friends at a local college.  It was
> > used, at the time, for a TEA laser power supply.  It's a 30 kV -at- ? mA.
> > The interesting portion of this is the fact its a DC supply.  It's got a
> > full wave bridge connected accross the output.  The whole thing is
> > submerged in XFMR oil.  Now the question: can I use a DC supply
> > appropriatly to operate a large system, or small one at that?
> >
> > Please comment with a detailed explanation.
> >
> > Another question.
> > Why is a synchronous, rotary, gap called that way?
> > My studies indicate that the best time to fire the gap is at the peak of
> > the AC waveform, to transfer the max energy.  How is this accomplished
> > when you have a rotating gap that is started (the motor that is) at we
> > don't know when, on the AC waveform?  Or do we have something that does
> > "synchronize" the firing of the gap with the peak of the AC waveform.
> >
> > The two questions do relate, for me.  If I use a DC power supply (full
> > wave rectification actually) how will a fire the gap appropriatly
> >
> > Thanks in advance.
> >
> > ChuckThanks for the info.

Here is another question.  With this laser power supply came a custom
made spark gap.  It consists of a 
special spark plug that forms a pre-ionizarion gap and one of the
electrodes of the SG.  The other electrode 
is on the opposite side and the whole thing is assembled with thick
plexi.  My tests show that 30 kv will not 
break down the gap because of it's distance.  If low pressure air is
allowed to flow into this pre-ionozation 
gap and the pre-I gap is fired the main gap will also fire.  Sounds like
a great scheme if I can generate and 
synchronize a pre-I spark.  What do you think?

Chuck