Original poster: "by way of Terry Fritz <twftesla-at-uswest-dot-net>" <sdate-at-gte-dot-net> Kent, You need one more detail... the output voltage. It may be an isolation xformer... 1 to 1 ratio... use a small AC voltage on the input/primary and measure the output voltage to find the ratio.... that will lead you to all the answers. steve - seattle