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Re: Discharge impedance of a CW Tesla coil

Terry, all,

Sounds like a very well regulated solid state TC, built by a pro ;-). I am
still curious to see a schematic, but I have yet to play with FET's and the
like, Tube's are much simpler!

I know some feel Ozone and NOx are not so bad, but do not be caught off
guard. I know that VTTC's (in both pulsed and CW mode) produce copious
amounts of these noxious compounds (gotta love the smell, though), but
perhaps the heat of the discharge helps to mix them with the air diluting it. 

You could modulated it with music, all adding tunes to the Tesla Lab...

Looking forward to further posts on this subject,

David Trimmell

At 11:09 AM 3/10/00 , you wrote:
>Original Poster: Terry Fritz <twftesla-at-uswest-dot-net>
>
>Hi John,
>
>At 08:44 AM 03/10/2000 -0500, you wrote:
>>In a message dated 3/10/00 6:41:05 AM Eastern Standard Time,
tesla-at-pupman-dot-com 
>snip..
>>
>>I wouldn't be surprised if the lower resistance seen in the CW coil is due
>>to the longer time period during which the sparks exist, which produces
>>more intense ionization over a smaller but "fuller" space.  Effectively
>>it's sort of like a disruptive TC which gives many streamers, but even
>>more intense because the sparks are there for a longer percentage of
>>time.  I suspect that disruptive TC's having multiple streamers will show
>>a lower than normal impedance also (but not as low as the CW coils).
>>It will be interesting to see if this impedance changes if the coil is
pulsed.
>>Short pulses (short "on-times") may be needed to appreciably increase
>>the streamer Z.  If we can increase the Z by pulsing the coil properly,
>>we may lengthen the sparks.
>
>Neat idea.  The generator does have a rear panel electrical connector for
>remote control of it's functions and I know it can be pulsed (I will have
>to find the specs on how fast but it is probably well into the kHz).  I
>don't have a duty cycle oscillator but a 555 timer with a handful of parts
>should provide the control signal easily enough.  I suppose it could play
>music and such off the discharge :-)
>
>> 
>>>  I noticed that this coil produces almost no ozone or other noxious
fumes in
>>>  operation.  I was very surprised by this!  Perhaps all CW coils are ozone
>>>  free and I just missed that bit of info.  Not gassing out the basement
>>>  during this testing is VERY pleasant as is the quiet discharge!!  It is
>>>  very cool but does not strike the "fear" those big disruptive coil
>>>  streamers, gaps, and all do...
>>
>>I generally get quite a lot of ozone from my tube coils but I've never really
>>done a proper comparison with the disruptive TC's.  The power levels
>>probably have a lot to do with it.  In a small room, running a tube coil
>>can be brutal.
>
>Really!!!  I wonder why this one is so free of ozone and those nitrous
>compound things???  I will look into this more.
>
>
>>
>>Good, let's get those old myths cleared away  :)
>>>  
>>>  I was very surprised that at
>>>  300 watts I was able to tune the coil with ZERO watts reflected (the
>>>  generator has a 50 ohm output through about 10 feet of RG-8).  My
primitive
>>>  computer models suggested such things but I didn't believe them...
>>>  Apparently, primary inductance is not at all critical but coupling is...
>>>  Of course, the RF generator is much more predictable than tubes (at least
>>>  for me)...
>>
>>A typical tube coil runs half wave rectified, so the various matching
>>aspects might not be as good?  I'll be interested to hear which coupling
>>k value you find to be the best.
>
>I use k=0.15 now because that just how it turned out and the computer said
>it would be ok.  Now that I know the discharge impedance, the computer can
>crank for optimal values.  Fortunately K is very easy to adjust.
>
>Cheers,
>
>	Terry
>