Re: Ammeter Question

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: coils-at-dslextreme-dot-com 

 > Original poster: "Aaron Aab" <striker754-at-earthlink-dot-net>
 >
 > Where can I find an AC ammeter to go inline with my hot power supply? I
 > would like to be able to measure the amps the transformers are drawing.
 >
 >
 >
Digi-Key sells panel mount analog meters up to 50 amps a/c for $71.80 part
# is 180-1079-ND.

If you are running under 1Kva, you can probably use your handheld
multimeter, just read the owners manual first, mine are only good up to 10
amps for short time periods.  If you are running high powers, you can use
an amp clamp or a current transformer.

I had this problem when I began useing more powerfull supplies.
Fortunately, I salvaged a 100:5 current transformer several years ago.  I
never new how to use it, but I found out on the list.  These are expensive
when new but you can find them as surpluss.  The critical part in my
circuit is a .2 ohm 5 watt current sense resistor.  This allows me to
place my digital meter across the secondary, and if the circuit sees 100
amps, my meter only sees 5 amps.  I have to multiply the reading by 20,
but it works beautifully.  I use a gapped E-I core ballast, thie current
monitor allows me to calibrate the ballast.

Look for used panel meters or current transformers at Murphy's in El
Cajon, CA, C and H sales in Pasadena, or Gateway electronics, in San
Diego,  I think they all have websites.

Good Luck and Safe Coiling,

Thad Howard