Active sensors for DC-current measurement
For accurate measurements of DC failures often Royer-Oscillators are used, e.g. in charging cables for e-cars, Wallboxes (household), public charging stations or even in the electric vehicle itself. This concept drives the core into saturation which leads to a change in the conducting phase of the transistor and the core will be saturated in the opposite direction. Due to a F-hysteresis loop (thin hysteresis curve) of Nanoperm, which implies a small remanenz and coercive force, small DC currents in the range of Milliamps can be well detected. Du to good temperature stability, the Nanoperm products can be used very well under changing environmental conditions.
Nanoperm helps to realize sensors which are capable to detect DC and AC current with various frequencies, so that the requirements of IEC 62752, IEC 62955, UL2231 can be kept without using an expensive RCD type B.