Re: Ammeter Question

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

Original poster: "Harold Weiss" <hweiss-at-new.rr-dot-com> 

Hi Thad,

I bought Yokogawa Horizon Line 2 1/2" panel meters from Electronic
Industries.  They ran between $26-36 for 0-30A self contained, magnetically
shielded ones.  Make sure you get the part number correct as you can't
return them if wrong.  I can even get 0-50A on special order.  The catalog
is at:

http://www.yokogawa-usa-dot-com/files/33/PANEL%20METER%CATALOG.pdf

David E Weiss

 > 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
 >
 >
 >