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Rolled cap margins?
To take into account that:
1. It is better to use 2 caps in series, rating each of them e.g. 10 kV DC,
instead of trying to built a single one for 20 kV DC. Thus, it is not worth
using 90 mils of dielectric if you are not going to stress the cap with more
than 10 kV DC (e.g. you can use an external safety gap on the cap).
2. Two dielectric layers are better than only one.
I have (again) modified my tentative capacitor design as follows:
- paper INNER LAYER
- Cu
- paper
- 0.2 mm LDPE
- paper
- 0.8 mm HDPE
- paper
- Cu
- paper
- 0.2 mm LDPE
- paper
- 0.8 mm HDPE OUTER LAYER
Paper is 0.05 mm (40g/m2) kraft paper not waxed.
HDPE is 0.8 mm (31 mil) HDPE
LDPE is 0.2 mm (7.9 mil) LDPE
Cu is 0.1 mm copper sheet
capacitor is filled with oil
If I rate this capacitor as a 10 kV DC device, how much wide is the margin
I have to leave on the electrode sheet sides? 1", 1.5" or how much?
Please, help me with this decision, because I wouldn't like to leave too much
space if it is not needed: that will reduce the capacitance very quickly :(
________________________________________________________________________
Marco Denicolai Vista Communication Instruments, Inc.
Hardware Development Manager www.vistacom.fi
marco-at-vistacom.fi Kaisaniemenkatu 13 A
fax: +358-9-622-5610 SF-00100 HELSINKI
phone: +358-9-622-623-15 Finland
Remember, Murphy was an optimist! I am not...
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