6 Dec
2005
6 Dec
'05
4:47 p.m.
On 12/6/2005 at 7:03 PM Scott Stevens wrote:
I would recommend using a high quality Constant
Current/Constant
Voltage bench supply. These have a 'current' and a 'voltage' knob
on them and two meters (someetimes one switchable meter). The
procedure I use is to set the voltage to the level that you want
the capacitor to reach while disconnected. Then turn the current
limiting way down and connect the capacitor. Monitor the current
while turning it up slowly and leave it at some comfortable low
level so the cap can form up. This process limits the current
while the cap forms up. You can watch the voltage meter, which
should climb up to what you had it set at, if the cap is any good.
Wouldn't this amount to the same thing as putting a hefty resistor in
series with a variac-controlled power supply with a voltmeter on the supply
side? Start low--the resistor limits the current--crank the variac up bit
by bit until the desired voltage is reached. A fuse isn't a bad idea
either, in case the dielectric just plain fails.
It's worked for me. And my power supply isn't anything more than a
transformer connected to the variac followed by a full-wave bridge
rectifier--no filtering needed.
Cheers,
Chuck