Original poster: Ed Phillips <evp-at-pacbell-dot-net> " I meant what i wrote: Shunts can be used on AC, as an alternative to current transformers. Yes, shunts are commonly used ON DC, they work fine on AC, also... best dwp" Of course, as long as they are calibrated for the frequency on which they're to be used or if that frequency is low enough that winding reactance doesn't count. Ed