[Prev][Next][Index][Thread]

Re: caps an the resonant freq.



to: Kerry

To make it simple --- use a vacuum pump or it won't work for long.  Just one
tiny bubble will emit corona near the dielectric, cause local heating, and
zap --- end of your cap.

Most any large Univ. Physics research dept will have a pump they probably
could help you do the pump down --- free if you ask the right people.  Most
larger high schools physics labs also have a vacuum pump.

All commercial manufacturers of high grade caps even keep their insulating
oil under vacuum until they pump it into the caps.  Most oils are slightly
hygroscopic --- very bad for cap construction.

Regards,

Dr.Resonance


-----Original Message-----
From: Tesla List <tesla-at-pupman-dot-com>
To: tesla-at-pupman-dot-com <tesla-at-pupman-dot-com>
Date: Tuesday, February 16, 1999 6:47 PM
Subject: RE: caps an the resonant freq.


>Original Poster: Kerry Jarrell <Kerry-at-apprentice-dot-com>
>
>will do, it sounds alot more managable, and configurable, but I got a
>question about how to make the cap without a vacume pump, I will have the
>funds for one in about 6 to 7 months but until then I was thinking of using
>vasaline and then heating it up to melt it and tryng to get the air out of
>the layers, how good is vasaline as a insolator in coiling?, I am just
going
>to play with it until I get the pump, anyone have any comments on that,
also
>does any one have any details on how the current shunts work in the neon
>transformers, I am unpotting one and am just wandering how those thing
>affect the current, I think it is shorting( for the lack of a better term)
>the flow of flux away from the windings but thats a swag, and I want
details
>on howe it works.
>
>kerry
>
>-----Original Message-----
>From: Tesla List [mailto:tesla-at-pupman-dot-com]
>Sent: Friday, February 12, 1999 11:59 AM
>To: tesla-at-pupman-dot-com
>Subject: Re: caps an the resonant freq.
>
>
>Original Poster: "Thomas McGahee" <tom_mcgahee-at-sigmais-dot-com>
>
>
>Kerry,
>Follow Ed's advice, but instead of building up the poly in multiple layers,
>make two or three single-thickness caps and wire them in series. This will
>make for a much more robust cap, and the extra aluminum foil is dirt
>cheap.
>
>The reason why such multiple series caps work out better is that each
>cap section only sees a fraction of the total voltage, and thus
>localized corona effects are GREATLY reduced. Corona is the great
>killer of caps. Most people who have used this technique would never
>go back to the old multi-layer cap designs. Try it.
>
>Fr. Tom McGahee
>
>> <<
>>  well I am reading the articals in the arcives about caps, and I read
some
>>  people are using .06" poly, or it reads 6 mill poly, my question is, is
>it
>>  hundreths of an inch or thousands that i should look for I got 2 sheets
>of
>>  hdpe of .03" thickness and I just want to make sure that I am not
>wasting my
>>  time building the caps with the wrong thickness of plastic
>SNIP
>>
>>  kerry
>>   >>
>> Kerry,
>>
>
>> Two sheets of .030" thick ldpe or hdpe is what you want - depending on
the
>> desired operating voltage of course.  In my opinion, two sheets of .030"
>is
>> good for about 9 kv ac maximum.  Three sheets are good for 12 kv
>operation.
>> You first calculate the resonant frequency of the secondary using its
>> inductance, self capacitance and the added capacitance of the top load
>> (toroid).  Now you calculate the resonant frequency of a primary coil and
>cap
>> to match the secondary frequency.
>>
>> Ed Sonderman
>>
>
>