I would imagine in crazy to not insulate all my HV driving gear, especially
until it enters the lower roller area. Also on the top load, if I don't
insulate the entering I get huge sparks jumping off, yet almost none with
good insulation. I still get leakage but i normally setup to arc out just
before leakage.
I mean I'm taking about immersing my setup in oil, just as is done on
almost every HV setup I've ever seen - especially where corona occurs. Also
without my lower insulating box surrounding the lower region, there is
strong tendency for the lower area of the collector to reach towards the
exposed metal components around the motor. As soon as I place the plastic
box with the hole for the tube it stops.
I think I need more explanation of what you mean this seems entirely
contrary to all my current experiments.
On Thu, Sep 10, 2015 at 12:40 AM, Carl Noggle <cn8@xxxxxxx> wrote:
> As a general rule, in HV design you should use as little insulation as
> possible, since dielectric surfaces charge up and distort the desired
> fields and create sliding sparks. Voltages can jump 4 or 5 times as far on
> a dielectric surface as in air. Attachments of dielectrics to metal should
> be done in low-field regions.
>
> ---Carl
>
>
>
>
>
>
> On 9/9/2015 3:55 PM, Matthew Sweeney wrote:
>
>> Yeah i built one before but i have a set of these nst sitting here needing
>> a use. With current limiting i think ill be safe there is no possible
>> conductive path up to the collecter and i use lots of insulating. Im
>> specifically interested in how a positive and negative vdg will interact
>> because i see noticeable differences when i switch the polarity on my
>> single vdg.
>>
>> All my rectifying and current limiting components will be potted and i use
>> HV cable upto 40K just to be sure. And that all goes in a plastic
>> container
>> covering the entire bottom section including motor, rollers etc.
>> On Sep 9, 2015 3:42 PM, "ExtremeElectronics.co.uk" <
>> tesla@xxxxxxxxxxxxxxxxxxxxxxxx> wrote:
>>
>> Why not use a fly back, If you look around you can find them with a
>>> tripler that will give you 30-40KV DC.
>>> The only down side is that you can't reverse the current
>>>
>>> There were some cheap ionizers on ebay a while back, they might be a good
>>> start too.
>>> For safety I'd aim for low voltage powered HV devices. I'd be very wary
>>> of
>>> using an NST. In a fault situation or a HV DC discharge from the VDG to
>>> the
>>> NST output, they could create a high current path to whatever the VDG was
>>> connected to, or arcing to at the time. This could easily be lethal.
>>>
>>> Derek
>>>
>>>
>>>
>>> On 09-Sep-15 6:11 AM, Matthew Sweeney wrote:
>>>
>>> Oh I forgot to mention, any good suggestions for current limiting here?
>>>> 30ma is far too much for a VDG am I'm sure most of it's going to be
>>>> wasted
>>>> anyway. Do i need a good old variac or some other cheaper alternative?
>>>> Will
>>>> a light dimmer really work i this situation?
>>>>
>>>> Thank you!
>>>>
>>>> Matt Sweeney
>>>>
>>>>
>>>> On Wed, Sep 9, 2015 at 12:01 AM, Matthew Sweeney <msweeney23@xxxxxxxxx>
>>>> wrote:
>>>>
>>>> Hello, all does anyone know a good source for HV diodes for rectifying
>>>>
>>>>> NST? Specifically up to 15KV at 30ma I would assume I need to account
>>>>> for
>>>>> RMS so probably around 20KV.
>>>>>
>>>>> I think I can get away with just one for half wave and maybe a cap for
>>>>> smoothing it a bit, but that would need to be a pretty decent cap to
>>>>> deal
>>>>> with 60HZ at that voltage.
>>>>>
>>>>> I'm using this to build a HV DC fed VDG does anyone have any hints or
>>>>> suggestions? I know I can find both diodes and caps in microwave ovens
>>>>> but
>>>>> its a pain to pull them apart and they are commonly too low voltage.
>>>>>
>>>>> I have found a few online retailers just wondering if there may be an
>>>>> alternate source, or anyone have some for sale etc.
>>>>>
>>>>> Thanks for any help!
>>>>>
>>>>> Matt Sweeney
>>>>>
>>>>> _______________________________________________
>>>>>
>>>> Tesla mailing list
>>>> Tesla@xxxxxxxxxx
>>>> http://www.pupman.com/mailman/listinfo/tesla
>>>>
>>>> _______________________________________________
>>> Tesla mailing list
>>> Tesla@xxxxxxxxxx
>>> http://www.pupman.com/mailman/listinfo/tesla
>>>
>>> _______________________________________________
>> Tesla mailing list
>> Tesla@xxxxxxxxxx
>> http://www.pupman.com/mailman/listinfo/tesla
>>
>>
> _______________________________________________
> Tesla mailing list
> Tesla@xxxxxxxxxx
> http://www.pupman.com/mailman/listinfo/tesla
>
_______________________________________________
Tesla mailing list
Tesla@xxxxxxxxxx
http://www.pupman.com/mailman/listinfo/tesla