Converter for Measurement of non-sinusoidal current peak value

A linear-response toroid with core wound of rapidly quenched soft magnetic metallic ribbon and fitted with two windings is used to enable correct measurement of mean peak value of non-sinusoidal and not noise-free alternating current. The time derivative of the current fed through the primary winding is obtained on the secondary of the sensor (or peak value converter, PVC). Evaluating the average value of this signal recovers the peak value of the primary current. A good quality average responding voltmeter is then used instead of peak-capture circuits which are often more susceptible to interferences and errors due to the superimposed noise. Certain advantages of using such sensor-converter as smoothing, amplification etc. as well as some drawbacks as possible distortion or peak intensification of the signal are discussed in some detail. Cores with characteristics linearized by different methods (e.g. field or stress anneal) are compared as to their PVC performance.