Bob Eager wrote:
On Thu, 28 Sep 2006 16:21:10 UTC, "Pet @ www.gymratz.co.uk ;¬)"

wrote:

The Natural Philosopher wrote:

More that the coiled up-ness of the big capacitor puts substantial
inductance in series with it.
DC Volts + Inductance ?

Not really an issue is it.

Also electrolytic capacitors have a
measurable internal resistance.
Yes, to a DC voltage a Capacitor has infinite resistance because it is
open circuit!

His point, I think, is that an electrolytic capacitor does not have
infinite resistance. (actually, no capacitor has infinite
resistance....)

The issue is RF suppression in the original comment about paralleling
capacitors. To preserve a low impedance across a broad range of
frequencies it is usual to have up to three capacitors - a large
electolytic, which is reaosanbly low impedance in the audio and
kilohertz sort of arena then something like a mylar layered capacitor,
which will do well up to a Mhz or tow and then something like a ceramic
disc, which can absorb frequencies in the 10-100MHz range, or higher.

Beyond that you are into black magic...every mm of wire will do SOMETHING.