In article ,
Gunner wrote:
On Sun, 29 Aug 2004 07:34:37 -0400, Steve Smith
wrote:



Tim Williams wrote:

"Gunner" wrote in message
...


Ive got around a dozen 7mf 1500 volt capacitors. What are they good
for?

[ ... ]

7 "MFD" (MicroFaraD), "mF" (miliFarad) or µF (micro-Farad)?

[ ... ]

If they can be picked up by hand, I suspect they aren't 0.007 Farad
1500V caps (i.e. milliFarad). Probably 7 micro farad.

[ ... ]

They are silver cans, rectangular in shape with rounded sides, about
8" tall, by 1.25 or so thick and 4" wide.

They say 7 MF 1500 volt. Internal resistor

*Way* too small for 7 mF -- almost certainly 7 uF.

Can you find anything which might be a date code on them? the
"7 MF" designation sounds really old.

I wonder about the internal resistor. It could either be a
parallel resistor to safely discharge it when the power source goes
away, or a series resistor to limit the current available from discharge.

If the former, it could be used for serious strobe lights --
especially if you parallel up a bactch of them.

If the latter (series resistor) I guess that it could be used
for high-voltage filtering (though it would not be as good as one
without the series resistor for fast changing loads).

However -- it the caps are stored without a wire connecting the
terminals (which is common on high-voltage caps) then I think that we
can assume that it is a parallel internal resistor for safely
discharging the caps.

So -- think electronic flash units -- including those to
optically pump a Nd-YAG laser.

Enjoy,
DoN.

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