An Experimental Method of Determining the Relationship between Current and Time in an Inductive Circuit
E.H. Frost-Smith · Journal of Scientific Instruments · 1949
The time-constant of a linear circuit is estimated, by applying to the circuit square voltage waves of zero minimum value, and measuring the mean current on a moving-coil instrument. Knowing the frequency of the voltage waves, and the current, the time-constant may be deduced. If a peak-reading instrument is employed the current after any time can be measured, and in this way the current-time relation for non-linear circuits may be ascertained. The method is suitable to measuring times of response down to about ½ msec.