Editing Current transformer (section)

==Special types==
Specially constructed ''[[wideband]] current transformers'' are also used (usually with an [[oscilloscope]]) to measure [[waveform]]s of [[high frequency]] or pulsed currents within [[pulsed power]] systems. Unlike CTs used for power circuitry, wideband CTs are rated in output volts per ampere of primary current.

If the burden resistance is much less than inductive impedance of the secondary winding at the measurement frequency then the current in the secondary tracks the primary current and the transformer provides a current output that is proportional to the measured current. On the other hand, if that condition is not true, then the transformer is inductive and gives a differential output. The [[Rogowski coil]] uses this effect and requires an external [[integrator]] in order to provide a voltage output that is proportional to the measured current.