Re: Microwave Oven Caps

["Tom Stathes" <newphreak_16-at-yahoo-dot-com> (by way of Terry Fritz <twftesla-at-uswest-dot-net>)]

Hello,
 In a series capacitor circuit the total voltage is
the sum of the voltages of all the caps.  The
capacitance can not be higher than the smallest cap. 
In a paralell circuit the voltage can not be higher
than the highest voltage, but the capacitence is the
sum of all the caps.  Its just like connecting
batteries or transformers in series and paralell. 

If i were to wire up all the caps in a box, and reopen
the oil fillhole case of each cap, then fill the box
with oil there should be no danger of explosion
because pressure couldnt build up right? 

Also, mabey you could help me out with this one. Or
mabey you know someone who can.

I just wound a new primary, its a flat spiral, 20
turns, 1/4" steel guy wire spaced about 1/4" apart. 
The inner diameter is 7.5" My secondary is 4.5"
diameter and 20" high (902 turns) of #24.  The tank
cap is ~10nf (wine bottles) and the tank input is 10kv
-at- ~133ma.  
I can't get corona discharge of no more than 7", my
top load is a spheroid of about 5" diameter. The first
turn of the secondary is 1 inch above the first turn
of the primary. Whats wrong, why do i get almost no
discharge? Should I adjust the coupling by lowering
the secondary a little? (I have to cut a hole in the
base of the primary to do this and i havent the time
to do it yet.)  
My less than spectacular other primary, (#12 wire
wrapped on a old 12"  laundry detergent bucket
(anything but even wire spacing)yielded sparks of up
to 18". 
 
Well thanks for any help you can give.
--Tom



--- Tesla list <tesla-at-pupman-dot-com> wrote:
> Original poster: Terry Fritz <twftesla-at-uswest-dot-net>
> 
> Hi Tom,
> 
> 	I don't really know right off...  Normally we want
> the nice low
> dissipation poly caps but ten microwave caps are
> pretty big and could
> dissipate a lot of heat on a small coil...  I guess
> I would be reasonably
> worried with a 1.3KVA coil.  If they are free or low
> cost there would not
> be harm in trying.
> 
> You say you will us a lower value lower voltage cap
> to go from 90nF to
> 33nF.  I don't think that works??  If you series a
> 90 nF and 52nF to get
> 33nF and put 10kV across them, 7300 volts will be
> across the 52nF cap.
> Perhaps I don't see what you mean there...  Your
> transformers may be able
> to charge the 90nF cap as is.  The resonant value of
> 30nF can be pushed
> much higher...
> 
> Cheers,
> 
> 	Terry
> 
> 
> At 10:44 AM 7/15/00 -0700, you wrote:
> >I was just wondering if i could use microwave oven
> >caps in series as my tank cap.  Would this work, or
> >would the caps just fail.  10 of these caps would
> be
> >about .09uf at 21kv ac.  I will then use a lower
> >voltage, lower value cap to drop the total
> capacitance
> >to the .03uf i need.  I plan to use a 10kv 133ma
> bank
> >of OBIC's to feed the tank.
> >Thanks for any help you can give. 
> >--Tom
> >
> >
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> 


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