Capacitors Used in Power Supplies

[John Larkin]

On Sat, 7 Feb 2004 11:26:20 -0500, Keith R. Williams
<krw@attglobal.net> wrote:

In article <5q0920h6am0rs4j7uidkulm7r04ndmglme@4ax.com>,
DarkMatter@thebarattheendoftheuniverse.org says...
On Fri, 6 Feb 2004 22:45:58 -0500, Keith R. Williams
krw@attglobal.net> Gave us:

DimBUlb, do you have a *clue* what an NP electrolytic is? ...I
thought not. Yikes, you are *DENSE*.

You retarded bastard. We use them in our designs at work, and we
also configure our own NP electrolytic storage configurations in house
with two caps so configured.

Then how do you explain these words (they're yours)?

There is no "back to back" with np type caps. They are just
plain "series" configured. And yes, the voltage drops across
them split, if they are of an equal value.

NP electrolytic capacitors *are* back-to-back electrolytics.
Putting them in series doesn't make them NP.

John Larkin was exactly right. You really should try to learn
from him, rather than constantly demonstrate your incompetence.


Ever see a laser pulser bank? I thought not. Try RIFA, and
Maxwell.

Again you bring up irrelevant issues to try to wiggle out of you
ignorance.

Keith,

I think DankMatter was taking issue with my statement about putting
*film* caps back to back. He is, I think, arguing that you can't put
them back-to-back, only in series. He is, I think, also being a
tedious ass, as usual.

Actually, for film caps that have an outside-foil stripe, back-to-back
does have meaning.

John

 

[Bob Myers]

"DarkMatter" <DarkMatter@thebarattheendoftheuniverse.org> wrote in message
news:530120tkqksrrf5r59quq22o1vlk5qvmpa@4ax.com...

Yes, and not always the choice to make. I have several times noted
that an 0402 0.1 uF cap, and an 0805 or 1206 0.1uF cap behave
differently in circuit, even with the same substrate.

We have a hard start cap for an oscillator that hates being a small
form factor.

I guess the answer could be that they perform differently with the
harmonics and such present in the signal, but there is no directly
observable reason. Still the fact remains that it will not work with
the smaller form factors in that location.

What do you mean "there is no directly observable reason"?
This is a rather well-known and completely understood phenomenon;
that there are performance differences between the same capacitance
value as provided by different form factors (even with the same
dielectric material and basic construction) is no mystery, and hasn't
been for years.

Go look up "self-resonance" or "ESR" just to get a couple of clues as
to why this might be so.


Bob M.