The present invention relates to a field-sensor device comprising a reference field sensor providing a reference sensor signal in response to a field, a calibrated field sensor providing a calibrated sensor signal in response to the field, a reference circuit connected to the reference field sensor and adapted to receive a reference signal, and an adjustable circuit connected to the calibrated field sensor and adapted to receive a calibrated signal. When the adjustable circuit is adjusted with the calibrated signal, said calibrated signal being different from the reference signal, the calibrated field sensor provides a calibrated sensor signal substantially equal to the reference sensor signal. The field sensor device is arranged to be exposed, when in a calibration mode, to a uniform calibration field and, when in operational mode, to an operational field being a field gradient.

A magnetic field sensor for sensing external magnetic fields on multiple axes comprises a coil structure and a gain equalization circuit. The coil structure generates reference fields on magnetic field sensing elements in each axis. The gain equalization circuit measures and compares reference fields to generate gain-equalized output signals responsive to the external magnetic fields.

A method for determining electric voltage u(t) and/or electric current i(t) of an RF signal in the time domain in a calibration plane, wherein by at least one directional coupler having two outputs and one signal input a first component of a first RF signal that runs from the signal input in the direction of the calibration plane, and a second component of a second RF signal that runs from the calibration plane in the direction of the signal input is decoupled. For a two-port error of the directional coupler, the error terms e.sub.00, e.sub.01, e.sub.10 and e.sub.11, are determined as a function of a frequency f and the signal values v.sub.1(t) and v.sub.2(t) are transformed into the frequency domain as wave quantities V.sub.1(f) and V.sub.2(f), and absolute wave quantities a.sub.1 and b.sub.1 in the frequency domain in the calibration plane are calculated from the wave quantities V.sub.1(f) and V.sub.2(f) by the error terms e.sub.00, e.sub.01, e.sub.10 and e.sub.11.

A touch detection device includes: an electrostatic capacitance detection device of each touch sensor; and a touch detection device to each touch sensor. The touch determination device obtains a maximum electrostatic capacitance, a minimum electrostatic capacitance and an intermediate electrostatic capacitance, and determines that the touch operation with respect to the touch sensor having the maximum change amount is performed when both of a first condition that a difference between the maximum electrostatic capacitance and the intermediate electrostatic capacitance exceed a second determination value and a second condition that a difference between the intermediate electrostatic capacitance and the minimum electrostatic capacitance is smaller than a third determination value are satisfied, and determines that a change of the electrostatic capacitance is caused by a noise when at least one of the first condition and the second condition is not satisfied.

A touch detection device includes: an electrostatic capacitance detection device of each touch sensor; and a touch detection device to each touch sensor. The touch determination device obtains a maximum electrostatic capacitance, a minimum electrostatic capacitance and an intermediate electrostatic capacitance, and determines that the touch operation with respect to the touch sensor having the maximum change amount is performed when both of a first condition that a difference between the maximum electrostatic capacitance and the intermediate electrostatic capacitance exceed a second determination value and a second condition that a difference between the intermediate electrostatic capacitance and the minimum electrostatic capacitance is smaller than a third determination value are satisfied, and determines that a change of the electrostatic capacitance is caused by a noise when at least one of the first condition and the second condition is not satisfied.

Systems and methods are disclosed that may be employed to calibrate current sense circuitry of CPU core voltage (Vcore) DC/DC voltage regulation circuitry by coupling an individual Vcore phase of a VR as a current source to a VSA phase of the same VR so that the Vcore phase acts as a current sink for the coupled Vcore phase during calibration of the current sense circuitry of the individual Vcore phase.

The occurrence of torque in the motor due to an unintentional flow of the q-axis current in the motor during discharging of the smoothing capacitor is reduced. A motor control device according to the present invention controls a system including an inverter including a smoothing capacitor connected to a power source via a relay, a motor connected to the inverter, and a current sensor configured to detect a current flowing through the motor, the motor control device including: an electric discharge control unit configured to discharge, in the motor via the inverter, an electric charge accumulated in the smoothing capacitor; and a current sensor calibration unit configured to calibrate the current sensor in a state where no current in the motor flows during a time period from when the relay is cut off to when discharge control by the electric discharge control unit is started, wherein the electric discharge control unit performs discharge by controlling the current in the motor based on a value of the current sensor calibrated by the current sensor calibration unit.

Methods and apparatus are disclosed to determine a power state of a device. An example method includes determining respective counts for a plurality of measurements during a calibration period, the measurements indicative of an amount of power drawn by the device, determining a first threshold and a second threshold based on at least one of the counts, the first threshold determined using most frequently logged measurement values, the most frequently logged measurement values based on counts performed after expiration of the calibration period, comparing a measurement to the first threshold and to the second threshold, and outputting a positive indication when the measurement is within an acceptable difference range, the acceptable difference range based on the amount of power drawn by the device.

Passive monitoring the integrity of current sensing devices and associated circuitry in GFCI and AFCI protective devices is provided. A protection circuit interrupter employs a capacitively coupled noise signal obtained by an arrangement of one or both of line side arms relative to a Rogowski coil. The noise signal is monitored while the line and load sides of a protective circuit interrupter are disconnected, and the connection of the line and load sides disabled if the noise signal fails to correlate sufficiently to a reference noise cycle. When the line and load sides are connected, the RMS value of the observed current signal is monitored such that the line and load sides are disconnected if the observed current signal fails to meet an RMS threshold. The observed current signal is compensated by subtracting the reference noise cycle prior to monitoring for the fault condition applicable to the protective device.

Passive monitoring the integrity of current sensing devices and associated circuitry in GFCI and AFCI protective devices is provided. A protection circuit interrupter employs a capacitively coupled noise signal obtained by an arrangement of one or both of line side arms relative to a Rogowski coil. The noise signal is monitored while the line and load sides of a protective circuit interrupter are disconnected, and the connection of the line and load sides disabled if the noise signal fails to correlate sufficiently to a reference noise cycle. When the line and load sides are connected, the RMS value of the observed current signal is monitored such that the line and load sides are disconnected if the observed current signal fails to meet an RMS threshold. The observed current signal is compensated by subtracting the reference noise cycle prior to monitoring for the fault condition applicable to the protective device.