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Re: Caps

>> > Wow, I just bought 2 rolls of poly at 3'X50' 4mil thinking I'm
>> > cool.  Just read an old text I saved that specs out 60mil as 
>> > the needed value.  I know that I can layer the plastic, but 
>> 
>> Yes, this is right. While you can use multi-layers in a rolled
>> capacitor, I do not think this is the most effective way to use
>> thinner dielectrics. If I had this material I would think hard
>> about constructing a vertical stacked flat plate capacitor.

Another capacitor that comes to mind would be several rolled capacitors 
connected in series.  The voltage would be distributed over the capacitors
evenly so that you would need about 15 of them. (15000 volts /60 mil ==
250v/mil * 4mil == 1000v).  Since the capacitors are in series and there
are 15 of them, you would need to make each one have 15 times the capacitance
that you want.  This may not be too hard because when the dielectric 
is thinner, the capacitance goes up.  (yeah, I'm sure that there are some
EE's out there that are cringing from the loose terminology)

Making 15 capacitors in this manner may be too much of a hassle though.  You 
may be better off using the plastic as a tarp or something useful and 
getting some 60mil PE.

Chip