Beckhoff SCT Series Documentation page 12

Product overview
Principle of the fluxgate current measurement technology
While all SCT transformers except the SCT5xxx are based on the transformer principle described above, the
technology of the all-current sensitive differential current transformers is fundamentally different.
Fig. 4: Principle fluxgate current measurement technology
The measuring principle of the SCT5xxx is based on a differential current measurement of two oppositely
excited cores in the transducer. For this purpose, both cores are brought into saturation with an excitation
winding (red) with an internally generated 32 kHz signal, whereby the first core is driven in the positive and
the second in the negative range of the y-axis. See fig.)
12 Version: 1.0 SCT5xxx