In Reply to: Re: Bypass caps, a little more information...You sure about that?... posted by Steve O on March 24, 2007 at 18:00:50:
DA is an inherent property of the dielectric AND construction.As i understand it, if you took the capacitor and unrolled it, what you would end up with is are two long strips, separated by the dielectric, with the electrodes connected either at one end, or the middle.
So, the problem with DA really has to do with the fact that some of the material is physically and electrically closer to the electrodes than the rest. You can eliminate DA by making all of the dielectric be equally spaced from the conductor. This is unfortunately, impossible.
So, one way to come closer to this is to parallel multiple caps. For instance, a 4uF cap may have a 4" wide strip (I'm making this up). With the maximum distance from the electrode being 2".
By using 2uF caps instead, you get the same capacitance as before, but the film strips are only 2" wide for each capacitor, in effect getting closer to this ideal.
But you know, this is all highly theoretical. I wish I had the time to construct Pease's test harness, I would love to try this with some inexpensive Solen's and see if there is any merit to what I'm saying or not.
Regards,
Erik
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Follow Ups
- Re: Bypass caps, a little more information...You sure about that?... - erik_squires@hotmail.com 12:24:47 03/25/07 (4)
- Re: Bypass caps, a little more information...You sure about that?... - Steve O 18:36:24 03/25/07 (1)
- Re: Bypass caps, a little more information...You sure about that?... - erik_squires@hotmail.com 18:46:34 03/25/07 (0)
- Re: Bypass caps, a little more information...You sure about that?... - Jim McShane 13:25:33 03/25/07 (1)
- Re: Bypass caps, a little more information...You sure about that?... - erik_squires@hotmail.com 14:29:28 03/25/07 (0)