Abstract: An arrangement for use in a utility meter comprises a transformer, a voltage source, a sensor, and a processor. The transformer includes a primary winding, a first secondary winding, and a second secondary winding. The voltage source is operably connected to generate a voltage signal and to provide the voltage signal to the first secondary winding. The generated voltage signal has a corresponding current formed at least in part by an impedance defined in part by a permeability of the transformer. The sensor is operably connected to generate a permeability signal indicative of the corresponding current. The processor is operably connected to the sensor and is configured to generate a hot socket detection signal responsive to the permeability signal indicating that the permeability of the transformer has fallen below a threshold value.

Abstract: A sensor includes a core, first and second windings, an integrating amplifier circuit and a DC balancing circuit. The first and second windings are wrapped around the core. The integrating amplifier circuit has a first input coupled to the first winding, and an output operably coupled to the second winding. The DC balancing circuit is operably coupled between the output of the integrating amplifier circuit and the first input of the integrating amplifier circuit.

Abstract: A current measurement circuit includes an integrator, first and second transformers, and a current measurement unit. The first transformer includes a first winding about a magnetic core. The magnetic core has an opening through which a current to be measured passes. The first winding is configured to generate a first current based on a first flux in the magnetic core. The second transformer includes second and third windings. The second winding is coupled to receive the first current from the first winding. The second winding has a terminal coupled to the third winding. The third winding is coupled to a first input of the integrator circuit. The output of the integrator circuit is operably coupled to provide an error current to the second transformer. The current measurement unit measures the current through the second winding of the second transformer.

Abstract: An arrangement for use in a utility meter includes a sensor and a processing circuit supported by a base of the meter, and a magnetic element carried by the cover of the meter, in which the cover is removably mounted to the base. The sensor includes at least two magnetizable elements, such as inductors, that are magnetized at opposite polarities when the meter is closed and operable. The magnetizable elements are positioned in very close proximity so that as cover is removed the magnetic element passes the elements to cause the magnetizable elements to assume the same polarity. The processing circuit continuously polls the magnetizable elements to evaluate their respective polarities and is configured to issue a tamper indication when the detected polarities are the same.

Abstract: A current measurement circuit includes an integrator, first and second transformers, and a current measurement unit. The first transformer includes a first winding about a magnetic core. The magnetic core has an opening through which a current to be measured passes. The first winding is configured to generate a first current based on a first flux in the magnetic core. The second transformer includes second and third windings. The second winding is coupled to receive the first current from the first winding. The second winding has a terminal coupled to the third winding. The third winding is coupled to a first input of the integrator circuit. The output of the integrator circuit is operably coupled to provide an error current to the second transformer. The current measurement unit measures the current through the second winding of the second transformer.

Abstract: An arrangement for use in a utility meter includes a sensor and a processing circuit supported by a base of the meter, and a magnetic element carried by the cover of the meter, in which the cover is removably mounted to the base. The sensor includes at least two magnetizable elements, such as inductors, that are magnetized at opposite polarities when the meter is closed and operable. The magnetizable elements are positioned in very close proximity so that as cover is removed the magnetic element passes the elements to cause the magnetizable elements to assume the same polarity. The processing circuit continuously polls the magnetizable elements to evaluate their respective polarities and is configured to issue a tamper indication when the detected polarities are the same.

Abstract: A sensor includes a non-magnetic core having a first winding wrapped thereon. The first winding has a center tap dividing the first winding into a first winding portion and a second winding portion. The center tap is coupled to a reference voltage. The first winding portion and the second winding portion are configured to sense first AC signals, and have a balanced susceptibility to second AC signals. The differential integrating circuit is configured to provide common mode rejection of the second AC signals. The differential integrator circuit is operably coupled to the first winding portion and the second winding portion.

Abstract: A sensor includes a core, first and second windings, an integrating amplifier circuit and a DC balancing circuit. The first and second windings are wrapped around the core. The integrating amplifier circuit has a first input coupled to the first winding, and an output operably coupled to the second winding. The DC balancing circuit is operably coupled between the output of the integrating amplifier circuit and the first input of the integrating amplifier circuit.