Apparatus and associated methods relate to an in-hole current-measurement system having three or more magnetic-field sensors and a transient-disturbance selection module configured to form an output signal from a selected subset of sensor signals while decoupling the output signals from a non-selected subset of sensor signals during a predetermined time window when a disturbance signal is expected at the non-selected set of sensor signals. In an illustrative example, a disturbance producing operation may be performed on alternating subsets of sensors while the undisturbed subset of sensors measures an electrical current in the electrical conductor. For example, each selected subset of sensors may be aligned on an axis configured to be mounted perpendicular to current flow within a hole in the electrical conductor. Some embodiments may advantageously provide continuous electrical current measurement while being uninterrupted by the predetermined transient disturbances.

Arrangements are disclosed for measuring small electrical currents with high sensitivity, for example in the context of sensing molecular entities, for example via interactions between the molecular entities and a membrane protein inserted in an amphiphilic membrane. In one arrangement there is provided a current sensing circuit (52) configured to integrate the current output by a sensor element (56) during each of a plurality of sensing frames (62). In each sensing frame (62) first and second analogue samples of the integral are taken during first and second time windows (71,72). A readout circuit (54) processes the first and second analogue samples to output a digital output signal representing the current output by the sensor element (56). The processing comprises analogue to digital conversion processing and output processing. The output processing is performed exclusively during periods outside of the first and second time windows.

The overcurrent protection device includes: a current detection unit configured to detect, as a sense voltage, a sense current flowing through a current sense terminal of a voltage-controlled semiconductor device; an overcurrent detection unit configured to compare the sense voltage detected by the current detection unit with an overcurrent threshold value to output an overcurrent detection signal; a mode determination unit configured to determine whether a superposition mode in which a transient sense voltage is superimposed on the sense voltage or a normal mode in which the transient sense voltage is not superimposed on the sense voltage; and a timing adjustment unit configured to adjust a detection start timing of the overcurrent detection signal based on a result of determination by the mode determination unit.

The present disclosure describes an apparatus, system, and method for cancelling noise (e.g., power supply noise). For example, the apparatus can include a load circuit, a sense resistor, and a current compensation circuit. The load circuit is configured to draw a first current (e.g., a load current). The sense resistor is configured to provide a voltage based on the first current. The current compensation circuit is configured to generate a second current (e.g., a compensation current) based on the voltage. A sum of the first current and the second current can be substantially constant.

A voltage detection circuit includes two detection capacitors, which are paired and configured differentially, first to third detection switches, a drive part, a minimum selector and a maximum selector. The first detection switch is formed of a pMOS transistor, which opens and closes a path between one of the detection capacitors and an input node. The second detection switch is formed of an nMOS transistor, which opens and closes a path between the other of the detection capacitors and an input node. The third detection switch is formed of a series circuit of a pMOS transistor and an nMOS transistor, which open and close a path between two detection capacitors. The driving part turns on and off complementarily between the first and second switches and the third detection switch. The minimum selector applies a lower one of voltages of the input nodes as a substrate potential of the nMOS transistor. The maximum selector applies a higher one of the voltages of the input nodes as a substrate potential of the pMOS transistor.

An apparatus and method for detecting transient voltage at an electrical component of a circuit board is provided. The apparatus including a circuit including a comparator and a latch, wherein a first input of the comparator is electrically coupled to the electrical component, and the comparator receives a threshold voltage at a second input, where the comparator outputs either a high signal or a low signal in response to both the first input and the second input, and an output of the comparator is electrically coupled to an input of the latch such that the latch outputs a high signal in response to receiving a high signal from the comparator, and an indicator electrically coupled to an output of the latch, and where the apparatus is mounted non-permanently to the circuit board to provide a non-permanent electrical coupling between the comparator and the electrical component.

A voltage sensor housing includes a top portion including a conductive top portion composed of conductive material and non-conductive top portions composed of non-conductive material, a bottom portion composed of non-conductive material, side portions composed of non-conductive material, wherein the top portion the bottom portion and the side portions define an interior area structured to hold a voltage sensor, and conductive side portions composed of conductive material and being disposed adjacent to the side portions. The conductive top portion is electrically floating and the conductive side portions are electrically grounded.

A current detection circuit includes: a resistor in a current path; first and second signal transmission units that transmit signals of first and second terminal sides of the resistor; a first difference operation unit that executes a difference operation on the signals transmitted by the first and second signal transmission units; a noise-capturing transmission unit starting point; third and fourth signal transmission units connected with the noise-capturing transmission unit starting point; a second difference operation unit that executes a difference operation on the signals transmitted by the third and fourth signal transmission units; and a summing operation unit that executes a summing operation on the first and second difference signals, wherein the first signal transmission unit and the fourth signal transmission unit are disposed close to each other and the second signal transmission unit and the third signal transmission unit are disposed close to each other.

An improved measurement system may include a source measure unit (SMU) capable of performing accurate low-level current measurements. Based on an SMU design that provides a controlled DC voltage source with precision current limiting and a controlled 0V (zero Volt) DC at the measurement terminal, an AC design may be implemented to establish the same (or very similar) conditions over a specified frequency range. Instead of controlling each digital-to-analog converter (DAC) at respective source terminals of the SMU as a respective DC output, each DAC may be controlled as a respective function generator with programmable frequency and continuously variable phase and amplitude. Off-the-shelf pipelined analog-to-digital converters (ADCs) may be used to monitor voltage, current and the voltage at the measurement terminal, and a Fourier transform may be used to obtain both the amplitude and relative phase measurements to be provided to respective control loops.

A control device for an AC rotary machine includes an AC rotary machine having m sets of n-phase windings, a current detector, a power converter, and a control unit that calculates voltage commands on the basis of respective differences between a current command for the AC rotary machine and current detection values obtained by the current detector, and outputs ON/OFF signals to high potential side switching elements and low potential side switching elements of the power converter by comparing applied voltages calculated on the basis of the voltage commands with a carrier wave signal, wherein the current detector, when detecting currents flowing through the n-phase windings on the basis of currents flowing through current detection resistance elements that are inserted in series into the low potential side switching elements, obtains current detection values at two or more fixed timings over a single period of the carrier wave signal.