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RE: Help...I'm having a lot of problems here...

you do not want to rectifie the transformer, the dc voltage is the most
lethale( not to say that ac is not), you do not want eltrolitics, they are
filter caps desinged to filter noise out of dc cercuits( well the most
commen aplacation) cermic is ok but you need to find enuff of them to
combine in the right configuration,( I would follow the advice allready
given by others) and cermics are not polerize in this aplaction you want non
polerize caps, and caps that are given a dc rating will work for ac but you
need to calulate the pk-pk voltage from the rms voltage of the transformer
and then add 10- 30% more voltage to it for a good margen and look for that
voltage, ie: I have 40kv cermic disk caps, they will work for 40 kvdc or
15kv ac Rms ( rms is root meen square avarge) I think you calulate it by( I
might be wrong if I am you need to look it up in a electrnics book) the
voltage Pk-PK times .707, to get pk-pk it is the voltage(rms)devided by .707
I think.... it has beb 9 years sence I used that I usaly look it up but I am
at work and do not have my book. so for 15 kv the pk-pk vollage is about 21
kv, but you need about 30 to 40 kv to handle any thing that my go above that
pk- pk voltage range just to be on the safe side, and if you can not find
them then call up a cap manufacture and see if you can get a sample of one
sent from one the distribers, though everyone keeps saying that cermic is
not a good choice for the caps in the long term and I would follow there
advice, but cermic will work I have got one to work with the caps that I
have, but I killed my transformer ( at the time I said choke it is just a
coil of wire I do not need one of those yeah I had no  clue what they were
for.) I would follow the advice of the ones with a little experance, and it
will work.

kerry



-----Original Message-----
From: Tesla List [mailto:tesla-at-pupman-dot-com]
Sent: Wednesday, February 17, 1999 1:04 PM
To: tesla-at-pupman-dot-com
Subject: Re: Help...I'm having a lot of problems here...


Original Poster: "Kent & Kim Schaffer" <santoken-at-bright-dot-net> 

Thanks for the rapid response, Malcolm.

>>
>> Power source:
>>
>>     Furnace transformer or NST (I'm not sure):
>>             -10KVA
>>             -25 milliamp
>>
>> Cap (set back for a good laugh):
>>
>>             -12x    2KVDC .01 uf ceramic caps soldered  in parallel for a
>> total of 24KVDC
>>                 -submerged in mineral oil in plexi box
>
>Hooking the caps in parallel doesn't alter the voltage rating at all.
>It remains that of the lowest voltage rated cap in the stack. What it
>does do is sum the capacitances. I'm guessing you've ended up with a
>0.12uF capacitor rated at 2kVDC.
>     Being limited to 25mA, the transformer is not going to charge a
>cap of that size to a very high voltage at all. Also, if you
>calculated your primary inductance to match the caps in series (i.e.
>0.01uF/12 or 833pF), the coil will be way out of tune. Note also that
>you will not get much energy at all from that capacitance charged to
>10kV (or 14kV peak).
>    I think you should aim to build a cap of about 6.6nF (0.0066uF)
>for that transformer. Primary coil will need to be adjusted so the
>tank tunes to the secondary of course.

Am I looking at the proper type of cap (ceramic)?  Should I be looking at
electrolytic caps?  The reason I ask is because I couldn't get any output
after hooking this unit up parallel with the transformer (i.e. one lead of
the cap to the hot and the other to the ground).  I was only able to get a
discharge at the gap when having the cap in series between the transformer
and the gap.  My understanding of the ceramic variety is they are not
polarized, or doesn't this matter?

Also, I was told today that the output of the transformer must be rectified,
that the output is AC and that caps will only work in DC.  Is this true?


>The radius of curvature is far too big for the amount of primary
>energy you are running. If you stick a metallic bump on it you should
>get something. However, get the primary capacitor and primary coil
>right first.
>
>Malcolm

I would assume you're talking of my toroid? And when you talk of a metal
bump do you mean like a door knob (or something of the likes)?

Kent