An energy harvesting device (CTH) installed in an electrical distribution system (EDS) for powering ancillary electrical devices (AD) used in the distribution system. The device includes a first voltage regulator circuit (CC) configured to produce a voltage matched to a power curve of a current transformer (CT) to which the device is electrically coupled. The device also includes a second and separate voltage regulator circuit (SVR) which continuously operates to maximize the amount of electrical energy recovered from the current transformer.

A current transformer (CT) for the purpose of, for example, current measurement, that uses a power line as a first coil and a second coil for measurement purposes, is further equipped with a third coil. Circuitry connected to the third coil is adapted to measure a signal therefrom. The measured signal from the third coil is compared to a signal measured from the second coil and based on the results, internal CT parameters are determined allowing calibration of actual results to expected results thereby providing an improved accuracy. This is especially desirable when using the CT for measurement of the like of current or phase of the primary coil when measurements are adjusted using the newly determined calibration parameters.

In an embodiment, a current sensor unit includes: a rectification module, to convert an AC current to a pulsed DC current; a conversion module containing an energy storage element, to store energy based upon the pulsed DC current during a charging mode and to generate a power supply current based upon a voltage of the energy storage element; a mode switching module, bypassed by the conversion module during operation in the charging mode, and bypassing the conversion module during operation in an energy release mode; a current sensor module, to detect a pulsed DC current flowing back from the conversion module or mode switching module; a control module, to acquire electrical energy from the power supply current, determine that operation is in the charging mode or energy release mode based upon the voltage of the energy storage element, and acquire a detection value provided by the current sensor module.

A current transformer (CT) for the purpose of, for example, current measurement, that uses a power line as a first coil and a second coil for measurement purposes, is further equipped with a third coil. Circuitry connected to the third coil is adapted to inject a known reference signal to the third coil of the CT. The injected reference signal, i.e., current, generates signals in the first and second coils of the CT. The signal generated in the second coil is compared using circuitry attached thereto to the reference signal. Based on the results, and the difference between the expected results and the actual results, updated calibration parameters are determined. These provide improved accuracy when using the CT, for example for measurement of the like of current or phase of the primary coil when measurements are adjusted using the newly determined calibration parameters.

The invention relates to a medical device (12) comprising an electrical measurement circuit (16), in which are connected at least two variable-impedance sensors (22), the impedance of which varies according to a detected physical quantity, an electrical power source (18) for supplying power to the electrical measurement circuit (16), an antenna (18) for emitting an electromagnetic field according to the impedance of the electrical measurement circuit (16), each of the sensors (22) being associated with a switch (24) for interrupting the current supply of the sensor (22) in said measurement circuit (16), the medical device (12) additionally comprising a system (26) for controlling the switches (24) in order to successively control the opening or the closing of the switches (24), according to determined configurations. The medical device (12) may in particular be applied to the human body or implanted within the human body.

The invention relates to a medical device (12) comprising an electrical measurement circuit (16), in which are connected at least two variable-impedance sensors (22), the impedance of which varies according to a detected physical quantity, an electrical power source (18) for supplying power to the electrical measurement circuit (16), an antenna (18) for emitting an electromagnetic field according to the impedance of the electrical measurement circuit (16), each of the sensors (22) being associated with a switch (24) for interrupting the current supply of the sensor (22) in said measurement circuit (16), the medical device (12) additionally comprising a system (26) for controlling the switches (24) in order to successively control the opening or the closing of the switches (24), according to determined configurations. The medical device (12) may in particular be applied to the human body or implanted within the human body.

The application provides a closed loop current transformer, in which a hall element is positioned in a notch of a magnetic ring and is used for generating an induced voltage according to the magnetic field generated in the magnetic ring by current to be measured. A first compensating coil and a second compensating coil are wound on opposite sides of the magnetic ring in the same winding direction. An input end of the power amplifier circuit is connected with an output end of the hall element, and an output end is connected with the first compensating coil and the second compensating coil respectively. The other ends of the first compensating coil and the second compensating coil are respectively connected with a signal detection circuit, and an output end of the signal detection circuit is used as an output end of the closed loop current transform.

Modern X-ray generators are required to deliver a peak power between 30 kW and 120 kW. This requirement places demanding constraints on the design of the power inverters used to supply such X-ray generators, at the same time that there exist industry incentives to reduce the size of X-ray generators. An trend towards increased frequencies of switching operation in the power stage of modern X-ray generators makes it possible to use air-core inductors, rather than magnetic-core inductors. This application discusses an air-core inductor assembly having an integral current sensor. According to this application, a current sensor can be more accurately provided, which does not drift in position over time, and in a way which reduces the overall bill of materials.

The invention relates to a medical device (12) comprising an electrical measurement circuit (16), in which are connected at least two variable-impedance sensors (22), the impedance of which varies according to a detected physical quantity, an electrical power source (18) for supplying power to the electrical measurement circuit (16), an antenna (18) for emitting an electromagnetic field according to the impedance of the electrical measurement circuit (16), each of the sensors (22) being associated with a switch (24) for interrupting the current supply of the sensor (22) in said measurement circuit (16), the medical device (12) additionally comprising a system (26) for controlling the switches (24) in order to successively control the opening or the closing of the switches (24), according to determined configurations. The medical device (12) may in particular be applied to the human body or implanted within the human body.

The application relates to a power switch for breaking an electrical circuit when current and/or current time span threshold values are exceeded, including an energy converter, which on the primary side is connected to the electrical circuit, and on the secondary side provides an energy supply for at least one control unit of the power switch. A choke is connected between the secondary-side output of the energy converter and the control unit of the power switch.