18 Jul
2001
18 Jul
'01
7:38 p.m.
On Thu, 19 Jul 2001, Tony Duell wrote:
Perhaps so named in deference to Leyden's original jar capacitor?
- don
+AD4- J +AD0- tolerance (which I can't remember, 10+ACU-?)
Don't eliminate +ACI-Joule+ACI- from consideration.
Seems like it would be one useful measure of
a Cap. (Uhhhh, Tony?)
Not really. While capacitors do store energy (measured in joules), the
energy stores is 0.5*C*V^2. So to know the energy stored in a capacitor,
you have to know the voltage. I have never seen a capacitor rated in
joules (meaning the amount of energy that can be stored at the maximum
working voltage of the capacitor) although it might makes sense for
things like photoflash capacitors.
One other unit we can discount is the 'jar'. This is actually a unit of
capacitance, IIRC, 1 jar = 1/900 uF. It was used by the (British) Royal
Navy (amongst others) until the mid 1930's IIRC. I have a few books which
give capacitor values in jars. I think, though that on any piece of computer hardware
it's safe to
assume the capacitors will be marked in some fraction of the farad and
the resistors marked in some multiple of the ohm.
-tony