On May 25, 20:19, William R. Buckley wrote:
Steve Leach said:
If you could humor my electronic ignorance, what
exactly
is a tantalum cap and how does it differ from a normal
capacitor? I was never before aware that there could be
more to a capacitor than plates (or foil) and an
electrolyte. How can a capacitor have a polarity?
Not an electrolyte, an insulator. It is the inability to
conduct electrons which gives the capacitor its ability to
collect electrons.
[...] Now, by being ionic, these electrolytes
are well suited to the conduction of electron flow. This
is most definately not the kind of behavior which you wish
to obtain from a capacitor.
Not from a capacitor as a whole, but if you look inside the "black
box"... The discussion was about electrolytic capacitors. Of course
they have an insulator (the oxide on the aluminium foil anode) but they
also have an electrolyte (which is the cathode), and indeed wouldn't
(don't) work without it. It's the ability of the electrodes to conduct
electrons that give the capacitor its ability to store them.
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Pete Peter Turnbull
Network Manager
University of York