The lead time at frequency F is given by Rb = burden resistor ; Lb = burden inductor ; Ls = inductance of CT secondary ; w = 2 * pi * F ; q1 = w * Lb / Rb ; q2 = w * Ls / Rb ; lead = arctan( q1 + 1/q2)/w seconds ; when Ls >> Lb -- Paul Nicholson -- _______________________________________________ Tesla mailing list Tesla@xxxxxxxxxxxxxx http://www.pupman.com/mailman/listinfo/tesla