Re: [TCML] X-ray cable best practices for feeder cable

["DC Cox" <resonance@xxxxxxxxxxxx>]

We have a very dedicated sec earth ground, so I'm certain it was not that
factor.

I, too, was very amazed to see 16" long sparks firing rapidly across the
insulator, and then discussed it with one of my former
colleagues from Univ. Wis. Dept. Plasma Physics, who told me about the
blumlien effect.  He said it's possible to to 4 x and even up to 6 x with a
single coaxial cable.  In his experience it punctured a 1.2" inch thick
coaxial cable repeated at various lengths along the cable.

Best regards,

Dr. Resonance




On Thu, Jan 8, 2009 at 10:33 PM, Peter Terren <pterren@xxxxxxxxxxxx> wrote:

> DC
> I don't question your observation but I offer a simple common explanation
> in the loss of secondary earth which will give sparks of any length you
> like.
> I would love to make 125kV sparks fom 14.4kV from a single coax as would
> others.
> I don't have the book. Could you explain the single coax multiplier
> components?
> Peter
>
> ----- Original Message ----- From: "DC Cox" <resonance@xxxxxxxxxxxx>
> To: "Tesla Coil Mailing List" <tesla@xxxxxxxxxx>
> Sent: Friday, January 09, 2009 11:14 AM
> Subject: Re: [TCML] X-ray cable best practices for feeder cable
>
>
> ok, then explain this:
>>
>> Running 14.4 kV into a standard Tesla oscillator circuit, I observed fat
>> capacitive sparks firing across a 125 kV BIL pole pig bushing.
>> I saw this with my own eyes so I know it is possible and I recommend using
>> a
>> safety spark gap to detect this ---- or keep buying pigs if
>> a resonance occurs.
>>
>> So, please explain how we went from 14.4 kV to in excess of 125 kV?
>>
>> This is certainly more than 2 or 4 times the input value.
>>
>> My only explanation is blumlien, and according to the book, Power
>> Electronics, by Sargent, it is possible with a single coaxial coil to
>> achieve this.
>>
>> D.C. Cox
>>
>> On Thu, Jan 8, 2009 at 5:59 PM, Peter Terren <pterren@xxxxxxxxxxxx>
>> wrote:
>>
>> DC and I disagree on this.
>>> In my opinion the most likely cause of huge arcs at the pig end is a
>>> disconnection of the secondary earth. The base of the secondary then arcs
>>> to
>>> the primary and puts the full TC voltage onto the primary line.  Easily
>>> gives huge arcs at the pig.  Ask me how I know.
>>> In my reading of Blumlein voltage multipliers using coax cable and spark
>>> gaps, it is possible to get 4 to ?8 times voltage multiplication with
>>> multiple gaps and complicated multiple coaxes. It is not just a simple
>>> coax
>>> and gap that will do it though.
>>> I use earthed coax for safety reasons.
>>> Peter
>>> www.tesladownunder.com
>>>
>>> ----- Original Message ----- From: "DC Cox" <resonance@xxxxxxxxxxxx>
>>> To: "Tesla Coil Mailing List" <tesla@xxxxxxxxxx>
>>> Sent: Wednesday, January 07, 2009 4:07 AM
>>> Subject: Re: [TCML] X-ray cable best practices for feeder cable
>>>
>>>
>>> Resonance can be quite wonderful, or, as Phil explains in his examples,
>>>
>>>> very
>>>> destructive.
>>>>
>>>> Resonance in your HV feeder cable is not something you want, so I avoid
>>>> using any feeder cable that is coaxial in nature, ie, has a ground
>>>> shield around it.  X-ray cables were designed strictly for DC power
>>>> transmission and not for transferring AC power.
>>>> Been there, done that ----- and it cost me a pole xmfr!
>>>>
>>>> Dr. Resonance
>>>>
>>>>
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