Current transformer with self-adjusting cores

#The apparatus described herein generally relate to a current transformer for attaching to and measuring electrical current through one or more electrical mains.

#Reducing electricity or power usage provides the benefits, among others, of saving money by lowering payments to electric companies and also protecting the environment by reducing the amount of resources needed to generate the electricity. Electricity users, such as consumers, businesses, and other entities, may thus desire to reduce their electrical usage to achieve these benefits. Users may be able to more effectively reduce their electricity usage if they have information about electricity usage.

#Power monitors for individual devices are available for measuring the power usage of a single device. For example, a device can be plugged into a power monitor, and the monitor can in turn be plugged into a wall outlet. These power monitors can provide information about power usage for the one device they are attached to, but it may not be practical to monitor all or even many devices in a house or building with these power monitors, because it would require a large number of devices that can be expensive and also require significant manual effort to install.

#FIG. 1 illustrates an exemplary and non-limiting embodiment of a current transformer in a closed position.

#FIG. 2 illustrates an exemplary and non-limiting embodiment of a current transformer in an open position with covers removed.

#FIG. 3A illustrates an exemplary and non-limiting embodiment of an exploded view of a current transformer.

#A power monitor may be installed in a building to obtain information about power usage within the building. For example, a power monitor may be installed in a conventional electrical panel, may be part of a smart electrical panel, or may be part of a smart electrical meter. A power monitor may determine information about power consumption by using sensors that measure an electrical property of the power mains (e.g., alternating current (AC) power line) that provide power to the building or an electrical property of power generated by solar panels. For example, where a building has two power mains, a power monitor may have a sensor (e.g., a current sensing device) for each of the two mains. In some embodiments, the sensors of a power monitor may include a current transformer, such as any of the current transformers described herein. A power monitor may have any of the characteristics of power monitors as described in U.S. Pat. Nos. 9,443,195; 9,699,529; or U.S. Pat. No. 10,586,177, each of which are incorporated herein by reference in their entireties.

#With reference to FIG. 1, there is illustrated an exemplary and non-limiting embodiment of a current transformer 100. Current transformer 100 includes in part a clamp formed of a semi-elliptical first housing 102 and a semi-elliptical second housing 104. First housing 102 is formed of first handle portion 108 and first distal portion 110. Likewise, second housing 104 is formed of second handle portion 112 and second distal portion 114. First distal portion 110 extends and terminates at first housing terminus 118 while second distal portion 114 extends and terminates at second housing terminus 122, such as including a mating portion 120 to reduce misalignment.

#First housing 102 and second housing 104 rotate axially about fulcrum point 106. Fulcrum point 106 defines, generally, the division between the second handle portion 112 and second distal portion 114 of second housing 104. Fulcrum point 106 similarly defines, generally, the division between the first handle portion 108 and first distal portion 110 of first housing 102. As described more fully below, an internal spring situated around the fulcrum point 106 provides rotational force to each of the first housing 102 and second housing 104 so as to render the current transformer 100 in a closed state with a first housing terminus 118 in contact with a second housing terminus 122.