A current detection circuit includes normally-on-type and a first normally-off-type switching elements with main current paths that are connected in series, and a second normally-off-type switching element that has a source and a gate that are connected to a source and a gate of the first normally-off-type switching element and a drain that is connected to a constant current source, and executes a division process by using drain voltages of the two normally-off-type switching elements.

The application provides a current detecting circuit, including a current transformer having a primary winding for receiving a current to be detected and a secondary winding for generating a sampling current; a demagnetizing circuit for demagnetizing the current transformer; a chip selection circuit electrically connected to the demagnetizing circuit, and operably switched between a first mode and a second mode; a sampling circuit electrically connected to the chip selection circuit to sample the sampling current, and outputting a sampling signal to a controller; and a clamping circuit electrically connected between the sampling circuit and the controller, and configured for providing a reference potential. The application further provides a converter including the current detecting circuit.

Current measurement devices for printed circuit board mounting are disclosed herein. The current measurement devices include a hollow and flexible core to improve response to a primary signal and decrease weight. The current measurement device includes a housing with guides to maintain alignment of the core. An electromagnetic shield may be placed between the circumference of the core and the housing. The housing may include apertures to facilitate washing. The current measurement device may include a primary conductor external to the housing.

A current sense resistor and a method of manufacturing a current sensing resistor with temperature coefficient of resistance (TCR) compensation are disclosed. The resistor has a resistive strip disposed between two conductive strips. A pair of main terminals and a pair of voltage sense terminals are formed in the conductive strips. A pair of rough TCR calibration slots is located between the main terminals and the voltage sense terminals, each of the rough TCR calibration slots have a depth selected to obtain a negative starting TCR value observed at the voltage sense terminals. A fine TCR calibration slot is formed between the pair of voltage sense terminals.

A sensor apparatus comprises an electrically conductive chip carrier comprising a busbar, a first connection and a second connection, and a differential magnetic field sensor chip which is arranged on the chip carrier and has two sensor elements. The form of the busbar is such that a measurement current path running from the first connection to the second connection through the busbar comprises a main current path and a bypass current path, wherein the main current path and the bypass current path run parallel to one another, and a bypass current flowing through the bypass current path is less than a main current flowing through the main current path. The magnetic field sensor chip is configured to capture a magnetic field induced by the bypass current.

The disclosure relates to a life prediction system for a fan of a lamp. The system comprises a fan signal detecting module to detect at least one working parameter of the fan; and a micro control unit to receive the working current signal, the environment temperature signal and the working rotation speed signal of the fan. The detecting module comprises a current detecting unit to detect a working current of the fan and output a working current signal; a temperature detecting unit to detect a working environment temperature of the fan and output an environment temperature signal; and a rotation speed detecting unit to detect and output a working rotation speed signal of the fan. The micro control unit calculates a predicted residual life of the fan based on the received working current signal, the environment temperature signal, the working rotation speed signal, through the life model of the fan.

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.

A system and method for monitoring a device includes a temperature sensor, a processing unit, and an output unit. The temperature sensor acquires a temperature measurement during a heat-up phase of a component and provides a temperature measurement to the processing unit, which selects a simulated transient temperature distribution of the simulated component of the simulated device from a plurality of simulated transient temperature distributions of the simulated component of the simulated device. The selection comprises a comparison of the at least one temperature measurement with the plurality of simulated transient temperature distributions at an equivalent time point in the simulated heat-up to a time point at which the temperature measurement was acquired. When a hot spot is developing an output unit outputs an indication of a fault associated with the component.

A magnetic core for a current sensor is provided. The magnetic core comprises a first and a second core part, each of which is formed from a stack made up of a plurality of sheet metal layers. The second core part has a first end piece structured such that some of the sheet metal layers are longer and protrude beyond the remaining, shorter sheet metal layers. The first core part has a second end piece which is structured inversely to the first end piece of the second core part. The first core part and the second core part are joined together at a connection point such that the longer sheet metal layers of the first end piece and the second end piece overlap at the connection point, wherein the overlap takes place at a number of interfaces that is at least two less than the number of sheet metal layers.

A measurement circuit comprises an input terminal to receive a current signal, a first circuit branch coupled to the first terminal and including one or more circuit elements to receive a portion of the current signal, a second circuit branch coupled to the first terminal and including one or more additional circuit elements to receive another portion of the current signal, a nonlinear circuit element coupling the first circuit branch to the second circuit branch, and a quantization circuit configured to produce an input current measurement of current in the first and second circuit branches, and to include current in the second circuit branch in the input current measurement according to a magnitude of the input current signal.