Abstract: A current sensor arrangement comprises plural sensor elements arranged around a centre point, each of the sensor elements having a plane of zero sensitivity to uniform magnetic fields. A first one (202) of the sensor elements has a first angular separation (X1) relative to the centre point from a second, adjacent sensor element (204) and a second angular separation (X2) relative to the centre point from a third, adjacent sensor element (206). The first angular separation is less than the second angular separation. An intercept (I13) of the planes of the first and third sensor elements is located outside a triangle formed by the centre point and the first and third sensor elements and an intercept (I12) of the planes of the first and second sensor elements is located inside a triangle formed by the centre point and the first and second sensor elements.
Abstract: An electrical current sensor and utility electricity meter, the current sensor comprising a &pgr; resistor shunt configuration, wherein the resistors comprise layered conductors at substantially equal temperatures to provide a zero temperature coefficient sensor. A fiscal electricity meter is described together with a four-layered current sensor fabricated using PCB techniques.
Abstract: A fiscal electricity meter is described for measuring the energy supplied to a load. The load current flows through the primary winding of a transformer and induces an EMF indicative of the current flowing in the secondary winding. The secondary winding comprises a sense coil, arranged to couple more strongly to the primary, and a cancellation coil which have equal and opposite turns area products so as to provide a null response to extraneous magnetic fields. The coils are arranged so that their magnetic axis are co-located and aligned together so that they also provide a null response to extraneous magnetic fields having a field gradient.
Type:
Grant
Filed:
November 6, 2000
Date of Patent:
July 2, 2002
Assignee:
Sentec Ltd.
Inventors:
Andrew Nicholas Dames, Edward Crellier Colby