There are included: generation means for generating predetermined information represented by a bit string; and control means for controlling a phase difference between current and voltage of AC power at predetermined time intervals so that each bit value included in the bit string is represented.

There are included: generation means for generating predetermined information represented by a bit string; and control means for controlling a phase difference between current and voltage of AC power at predetermined time intervals so that each bit value included in the bit string is represented.

In a meter for performing a measurement of an electrical parameter, an output from a sensor is sampled to produce at least one sample, and an iterative method is performed comprising: producing further samples; holding in memory a stored array of samples comprising the at least one sample and each of the further samples from each iteration; determining a measure of statistical variability of a mean for the respective iteration from a measure of statistical variability and from the number of samples used to generate the measure of statistical variability; comparing the measure of statistical variability of the mean with a pre-determined threshold; and generating an electrical signal indicating a state of the measurement if the measure of statistical variability of the mean of the samples taken during the measurement is less than or equal to the pre-determined threshold.

A method and device for increasing an accuracy of a phase measurement, wherein the method includes: receiving a measurement signal; performing a frequency-domain transformation to the measurement signal to obtain a frequency-domain measurement sequence; determining phases that correspond to frequency-domain measurement signals, and determining a phase difference between the frequency-domain measurement signals that correspond to two neighboring specified frequency points; according to the phases, the phase difference and a window function, performing a sliding-window-type phase fitting to the frequency-domain measurement sequence, to obtain phase-fitting data that correspond to sliding windows; and according to the phase-fitting data of the sliding windows, determining phase-calibration data that correspond to the sliding windows, and, by using the phase-calibration data of the sliding windows, forming phase-calibration data within a specified frequency band. The method reduces an error of fitting, and increases an accuracy of a phase calibration.

An induction heating device includes a working coil, an inverter including a first switching element and a second switching element that are configured to perform a switching operation and to apply a resonance current to the working coil, a snubber capacitor including a first snubber capacitor connected to the first switching element, and a second snubber capacitor connected to the second switching element, a phase detector configured to detect a phase difference between the resonance current applied to the working coil and a switching voltage applied to the second switching element, and a controller configured to receive, from the phase detector, phase information including the phase difference, provide the inverter with a switching signal to thereby control the switching operation, and adjust an operating frequency of the switching signal based on the phase information to thereby control an output of the working coil.

A method for the correction of synchronization errors Δt in the measurement of the impedance of an electrical or electrochemical component, more particularly a lithium ion cell is provided. In general, synchronization errors in an impedance measurement can arise between the excitation and response signals, which can misrepresent the phase of the impedance value obtained. According to the method, the synchronization error can be determined by measuring the impedance at two different frequencies and solving an optimization problem in respect of the deviation of the phases from an equivalent circuit diagram, which comprises at least one resistance and an inductance. The phase of the impedance value obtained can be corrected in this way.

System and methods for high accuracy, non-intrusive current sensing are provided. A system may include two magnetic field sensors configured for differential sensing. The system may further include frontend circuitry configured to remove direct current (DC) offset of the magnetic field sensors, upconvert the outputs of the magnetic field sensors, and filter out at least one frequency component from the up-converted signals. The system may receive output signals from the front-end circuitry corresponding to each sensor. The system may further calculate a differential signal based on the output signals. The system may apply optimal detection based on the differential signal and a reference signal to calculate a measurement of current flow. The system may determine a phase angle measurement between the differential signal and the reference signal to calculate a direction of the current flow in the conductor and output various measurement information related to the detected current.

System and methods for high accuracy, non-intrusive current sensing are provided. A system may include two magnetic field sensors configured for differential sensing. The system may further include frontend circuitry configured to remove direct current (DC) offset of the magnetic field sensors, upconvert the outputs of the magnetic field sensors, and filter out at least one frequency component from the up-converted signals. The system may receive output signals from the front-end circuitry corresponding to each sensor. The system may further calculate a differential signal based on the output signals. The system may apply optimal detection based on the differential signal and a reference signal to calculate a measurement of current flow. The system may determine a phase angle measurement between the differential signal and the reference signal to calculate a direction of the current flow in the conductor and output various measurement information related to the detected current.

The present invention relates to a hair removal device, such as an electric shaver or epilator, comprising a hair cutting unit, a motor for driving the hair cutting unit, a measurement unit for measuring motor current and/or induced voltage and a cutting activity determinator for determining cutting activity from the half cycles of the signal of said measurement unit, wherein a wear determination unit is provided for determining wear of the hair cutting unit from the cutting activity signal of said cutting activity determinator.

The present invention relates to a hair removal device, such as an electric shaver or epilator, comprising a hair cutting unit, a motor for driving the hair cutting unit, a measurement unit for measuring motor current and/or induced voltage and a cutting activity determinator for determining cutting activity from the half cycles of the signal of said measurement unit, wherein a wear determination unit is provided for determining wear of the hair cutting unit from the cutting activity signal of said cutting activity determinator.