CPC H05B 47/25 (2020.01) [G01R 19/16571 (2013.01); G01R 22/065 (2013.01); H02H 1/0007 (2013.01)] | 14 Claims |
1. A circuit for energy metering and surge current detection, comprising:
a current transformer having a primary winding and a secondary winding (L2, L3);
a first current sensing arrangement connected to the secondary winding, for energy metering; and
a second current sensing arrangement connected to the secondary winding, for surge current detection, wherein the second current sensing arrangement comprises a high pass filter, wherein the secondary winding comprises first and second winding portions in series, wherein a virtual earth is defined at the junction between the first and second winding portions, and the ends of the first and second winding portions opposite the junction each connect to a transformer output through a respective forward diode, and wherein the first and second current sensing arrangement are each connected to the transformer output and to the virtual earth.
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