A current sensor includes a conductor, and first and second magnetic sensing elements. The first magnetic sensing element is positioned such that the magnetic field component in the second direction of the magnetic field generated by the measurement target current flowing through the first conductor portion is opposite in polarity to the magnetic field component in the second direction of the magnetic field generated by the measurement target current flowing through the third conductor portion. The second magnetic sensing element is positioned such that the magnetic field component in the second direction of the magnetic field generated by the measurement target current flowing through the second conductor portion is opposite in polarity to the magnetic field component in the second direction of the magnetic field generated by the measurement target current flowing through the third conductor portion.

A nested ammeter for measuring the electrical current flowing through a device under test (DUT) can include an input configured to receive an input signal having a frequency within a frequency band and representing the electrical current flowing through the DUT. The nested ammeter can also include an output configured to generate an output voltage representing the electrical current flowing through the DUT. An active shunt can be used as the resistive feedback of the ammeter. A nested active shunt can be used as the resistive feedback element of the active shunt.

A current sensing system includes a pre-calibrated busbar, a voltage sensor, a temperature sensor and a controller. The pre-calibrated busbar has a known resistance, a known variation in resistance with respect to temperature and known dimensions. The voltage sensor detects a difference in voltage between a first location and a second location on the pre-calibrated busbar. The temperature sensor detects an ambient temperature of the pre-calibrated busbar. The controller determines a resistance of the busbar between the first location and the second location based on the known resistance, known variation in resistance, known dimensions and the ambient temperature. The controller additionally determines a current flowing through the pre-calibrated busbar based on the difference in voltage and the determined resistance. The current sensing system has numerous applications including using the determined current to control an operating condition of a solid state circuit breaker or a solid state power controller.

Certain aspects of the present disclosure are generally directed to circuitry and techniques for voltage-to-current conversion. For example, certain aspects provide a circuit for signal amplification including a first amplifier; a first transistor, a gate of the first transistor being coupled to an output of the first amplifier and a drain of the first transistor being coupled to an output node of circuit; a first resistive element coupled between a first input node of the circuit and an input of the first amplifier; a second amplifier; a second transistor, a gate of the second transistor being coupled to an output of the second amplifier and a drain of the second transistor being coupled to the output node of circuit; and a second resistive element coupled between a second input node of the circuit and an input of the second amplifier.

A power conversion device includes: a plurality of legs, each leg including a high-side switch connected between a voltage supply node and a phase node and a low-side switch connected between the phase node and a reference node; a phase current sensor for each leg and configured to sense current flowing through the high-side switch or the low-side switch of the corresponding leg; a single current sensor connected between the reference node and the low-side switches, or between the voltage supply node and the high-side switches; and a controller. During a subperiod of a switching period, the controller is configured to sample the current sensed by at least one of the phase current sensors and a current sensed by the single current sensor such that the current in one or more of the legs is sampled during the same subperiod as the current flowing through the single current sensor.

A detection apparatus is for detecting interference on signal paths in a differential voltage measuring system with a signal measuring circuit for measuring bioelectric signals with a number of useful signal paths having at least one shield. In an embodiment, the detection apparatus includes at least one analysis unit, connected to the shield and embodied to detect interference in a useful signal path of the voltage measuring system via a signal measured at the shield in the case of interference.

A measuring circuit (100) is described, for the voltage of an electric machine comprising a first operational amplifier (20) having its non-inverting input (5) connected to a non-inverting input (10) of at least one second operational amplifier (30), and its output (7) feedback connected, through a resistance (R5), to the inverting input (6), the inverting input (6) of the first operational amplifier (20) being further connected through a resistance (R6) to a first phase (C) of the input current to an electric machine, the output (7) of the first operational amplifier (20) being connected, through a resistance (R8), to the inverting input (2) of a third operational amplifier (40) which has its non-inverting input (3) connected to a reference voltage (VREF), the output (7) of the first operational amplifier (20) being further connected to a first output (VC) of the circuit, which is at a voltage value equal to the voltage of a first phase of the electric machine to be measured, said third operational amplifier (40) having its output (1) feedback connected, through a capacitance (Cl), to the inverting input (2), the output (1) of the third operational amplifier (40) being further connected through a resistance (R10) to the non-inverting input (5) of the first operational amplifier (20) and to the non-inverting input (10} of the second operational amplifier (30); a system and a process for calibrating electric machines using such circuit (100) are further described.

A voltage comparator and an operation method thereof are provided. The voltage comparator includes an amplifying circuit, a reference current source, and a transient current source. A first input terminal and a second input terminal of the amplifying circuit respectively receive a first corresponding voltage corresponding to a target voltage and a reference voltage. The reference current source is coupled to the amplifying circuit to provide a reference current. The transient current source is coupled to the amplifying circuit to selectively provide a transient current. The transient current source detects a transition of a second corresponding voltage corresponding to the target voltage to dynamically adjust the transient current. Therefore, when a rapidly increasing voltage occurs in the target voltage, the transient current source may temporarily increase the current of the amplifying circuit, thereby accelerating the response speed of the amplifying circuit.

A method for measuring a heat generation distribution in a honeycomb structure includes: applying a voltage to a pair of electrode layers of the honeycomb structure to bring the honeycomb structure to an electrically conductive state; measuring resistance values R.sub.n between two different points on the surface of an outer peripheral wall of the honeycomb structure; estimating a current value I.sub.n flowing between the two points using Kirchhoff's law based on each of the resistance values R.sub.n between the two different points, and calculating a heat value generated for each of the resistance values R.sub.n based on each of the resistance values R.sub.n and the current value I.sub.n; and estimating a heat generation distribution in the honeycomb structure based on both the positions at which each of the resistance values R.sub.n is measured, and the heat value calculated from each of the resistance values R.sub.n, in the honeycomb structure.

Provided are embodiments for circuit for detecting an open-wire condition for a differential input. Embodiments include a sensor, and a line replaceable unit (LRU) coupled to the sensor, wherein the LRU comprises a differential amplifier to provide a sensor output. Embodiments can also include a synchronous demodulator coupled to an output of the differential amplifier through an alternating current (AC) coupling network, wherein the synchronous demodulator is configured to receive the differential amplifier output and a reference signal at the synchronous demodulator signal input and reference input, and provide a synchronous demodulator output voltage to indicate an open-wire condition. Also provided are embodiments of a method for detecting an open-wire condition for a differential input.