Current sensing circuit and current measuring system for measuring a current in an electrical line

A method for measuring a current in an electric line connecting an electrical supply to a load, the method comprising:

• supplying a reference current to a reference winding, wherein the reference winding is wound around a magnetic core;
• detecting a change in condition of the magnetic core, based on the supplied reference current and generating a detection signal in response to determination of the change;
• and
• measuring the current in the electrical line in response to the detection signal, wherein the detection signal is indicative of the change in the condition of the magnetic core.

An electric vehicle supply equipment (EVSE) comprising:

• a current sensing circuit for measuring a current in an electrical line connecting an electrical supply to a load, the current sensing circuit comprising:
• a magnetic circuit having a magnetic core, a reference winding wound around the magnetic core, and a conductor passing through center of the magnetic core, the conductor being connected to the electrical line;
• a detection circuit connected to the reference winding of the magnetic circuit, wherein the detection circuit is configured to detect a change in condition of the magnetic core and generate a detection signal in response to determination of the change;
• and
• a controller coupled to the detection circuit for receiving the detection signal, where the controller is configured to measure the current in the electrical line in response to receiving the detection signal from the detection circuit.