[Prev][Next][Index][Thread]
Re: Rolled Caps
At 10:25 PM 2/4/97 -0700, you wrote:
>Subscriber: Rodney.Davies-at-anu.edu.au Tue Feb 4 22:11:23 1997
>Date: Wed, 5 Feb 1997 01:13:32 +1100 (EST)
>From: Rodney Graham Davies <Rodney.Davies-at-anu.edu.au>
>To: tesla-at-pupman-dot-com
>Subject: Rolled Caps
>
>Hi All,
>
>Um, I think R.Quick posted a message a long time ago about
>calculating/designing rolled capacitors.
>
>I was just curious to know if anyone has got the formula for calculating
>the capacitance for a rolled cap?
>
>I'm looking at building a couple, but need to design for around 0.09uF,
>so far the doc's I've read from the funet.fi site are designs for smaller
>valued types (around .02uF), so I thought if there's a formula out there, it
>would be a fantastic guide to design and construction.
>
>I'm also needing the voltage rating to be around 40-50KVDC as the
>pig-pole I'm using is 12700V -at- 0.787A (10KVA), and the calculated
>capacitance required for my coil is 0.187uF. Which makes this transformer
>fairly ideal...
>
>Thanks Guys!
>
>Catchya's Later!
>
>Rod 'Down Under
Rod,
Rolled caps are just two plate, flat capacitors, times two!!!
Use the standard flat plate equation- .224 X dielectric constant of
dielectric X area of one of the two plates in square inches. divided by the
thickness of the dielectric in inches. Now multiply by 2 for a rolled
capacitor. This will do it to a moderate degree of accuracy. The answer is
in picofarads.
Richard Hull, TCBOR
>
>
>
>