On Thu, 30 Mar 2006 19:19:12 GMT, Ignoramus27088
wrote:

Got myself some capacitors for $10 apiece.

http://cgi.ebay.com/ws/eBayISAPI.dll...tem=7603382621

The specs are 22 kV, 1 uF, discharge capacitor. See

http://igor.chudov.com/tmp/cap.jpg

The seller was wrong in describing them as 22 VOLT capacitors. They
are 22 KILO volt capacitors. (the seller is Fermilab).

They are similar to this one:

http://cgi.ebay.com/ws/eBayISAPI.dll...tem=7598631638

but have twice more capacitance.

Anyway, here is my question. I have a 9 kV DC power supply. (a
Franceformer). How can I safely test these caps before selling
them. At 22 kV, they can store about as much energy as a .22 bullet,
according to my calculations.

It would be less at 9 kV, but still, obviously, very deadly.

So. What is a safe way to charge them, verify that they hold the
charge, and then DIScharge them at 9 kV.

i

Are you sure your Franceformer produces DC? Most of them are AC, as
for neon signs and oil ignitors.

Don Foreman wrote:
On Thu, 30 Mar 2006 19:19:12 GMT, Ignoramus27088
wrote:


Got myself some capacitors for $10 apiece.

http://cgi.ebay.com/ws/eBayISAPI.dll...tem=7603382621

The specs are 22 kV, 1 uF, discharge capacitor. See

http://igor.chudov.com/tmp/cap.jpg

The seller was wrong in describing them as 22 VOLT capacitors. They
are 22 KILO volt capacitors. (the seller is Fermilab).

They are similar to this one:

http://cgi.ebay.com/ws/eBayISAPI.dll...tem=7598631638

but have twice more capacitance.

Anyway, here is my question. I have a 9 kV DC power supply. (a
Franceformer). How can I safely test these caps before selling
them. At 22 kV, they can store about as much energy as a .22 bullet,
according to my calculations.

It would be less at 9 kV, but still, obviously, very deadly.

So. What is a safe way to charge them, verify that they hold the
charge, and then DIScharge them at 9 kV.

i


Are you sure your Franceformer produces DC? Most of them are AC, as
for neon signs and oil ignitors.

I took Iggy at his word since he said it was DC and he seems knowlegable
about what he wants to do.

So tell us Iggy, is it truly a 9 kv DC supply?

If it isn't, maybe we can use our metalworking and mechanical skills to
help him design a syncronous motor driven mechanical rectifier switch to
get the DC he needs, G

Jeff

--
Jeffry Wisnia

(W1BSV + Brass Rat '57 EE)

"Truth exists; only falsehood has to be invented."

On Fri, 31 Mar 2006 02:35:57 GMT, Ignoramus27088 wrote:
On Thu, 30 Mar 2006 21:11:08 -0500, Jeff Wisnia wrote:
So tell us Iggy, is it truly a 9 kv DC supply?

I think that Don is right, the franceformer does not say DC or AC, so
I think that it is most likely AC.

That'd seriously limit it's usefulness in charging a cap, unless you've
got some of them thar fancy AC capacitors.