[TCML] New Coil Questions

[David Rieben]

Hi Tyler,

I think others have already addressed your questions
here but I will just add this little bit about x-ray cable.
High voltage x-ray cables are the lines used to trans-
fer the HVDC and the low filament voltage from the
high voltage transformer supply to the x-ray tube head.
They usually consist of two or three individually insu-
lated (for low voltage) wires (usually around #14 or #
16 braided conductor) in the center. This conductor
bundle is wrapped with a thick layer of rubber insulation,
which is for the high voltage standoff. Around the out-
side of this thick rubber sheathing is usually a wrap of
carbonized semiconductor tape and around the tape is
a metal braided sheating, which is connected to ground.
Finally, around the outside of the metal braiding is a
thin rubber outer protective sleave. Finally, the end
terminations are usually a special male plug end that
fits into the female receptacle ports of the HV transfor-
mer and the x-ray tube heads. Here is a picture of
several rolls of x-ray cable that I recently aquired:
http://www.flickr.com/photos/33464569@N05/3408614009/

David Rieben


----- Original Message ----- 
From: "Tyler Pauly" <rpggod714 at yahoo.com>
To: "Tesla Coil Mailing List" <tesla at pupman.com>
Sent: Wednesday, May 27, 2009 10:20 PM
Subject: Re: [TCML] New Coil Questions


>
> I have more questions on the following two.
>
>> 7)  Can I wire an arc welder in series with my outlet leads to current 
>> limit?  I would think so, but again, it doesn't hurt to ask.
>
> Yes, a 225 amp stick welder with its 240 input leads in
> series with the input leads to the pig can be used as a ballast.
> Many people that go this route simply short the output welding
> leads and use the amp selector switch for input current control.
> However, as Scot has also already mentioned here, most arc
> welders are made as cheaply as can be gotten away with and
> typically have like a 20% duty cycle at their maximum setting.
> I finally ended up making a homemade ballast from the core
> of a defunct x-ray transformer. You would have to make sure
> that your core has sufficient cross sectional area to handle the
> power that you're looking to control, too. Others can comment
> on formulae for this.
>
>
> I've heard of people using a PVC pipe as a form to wind heavy wire around, 
> and sticking welding rods inside to form an inductive ballast.  This 
> sounds somewhat cheap and very easy, but will it work?  What could go 
> wrong, what should I take into account etc.?
>
>
>
>> 8)  My pig only has 1 HV bushing, so should I just split the wiring I 
>> attach to it to get 2 leads off of it to make the primary circuit?  Sorry 
>> for the bad wording, I hope I get my question across.
>
> I also use a "single eared" pig to drive my current big coil with
> out any problems. I isolate the case "return" of the pig as RF
> ground and do not allow it to be attached to mains ground so
> that the nasty RF kickbacks don't end up on the metal
> surfaces of my control panel and bite me. ;^0 "I" use
> that high voltage rated x-ray cable to run the HV from my
> pig to my tank circuit and hook the single output bushing of
> the pig to the inner conductors of the cable and the outer tank
> to the outer braiding of the cable. This cable is basically coaxi-
> al cable on steroids and is generally rated at around 75 kVDC.
>
>
> I'm a little confused on both responses to this question.  For your 
> answer, where do I get some of this cable?   And what is the second object 
> I'm connecting the cable to?  I'm not very familiar with the lingo used 
> with pigs.
> So does this cable have two insulated conductors inside?  If I were to use 
> normal cable with only one conductor, I would be connecting an end to the 
> bushing and the other end to.... what again?   =P
>
> Thanks again!
>
> Tyler
>
>
>
>
> _______________________________________________
> Tesla mailing list
> Tesla at www.pupman.com
> http://www.pupman.com/mailman/listinfo/tesla