An oscillator-based sensor interface circuit includes first and second input nodes arranged to receive first and second electrical signals representative of an electrical quantity, respectively; an analog filter; a first oscillator arranged to receive a first oscillator input signal and a second oscillator different from the first oscillator and arranged to receive a second oscillator input signal; a comparator arranged to compare signals coming from the first and second oscillators; a first feedback element arranged to receive a representation of the digital comparator output signal and to convert the representation into a first feedback signal to be applied to the oscillation means; a digital filter arranged to yield an output signal, being an filtered version of the digital comparator output signal; a second feedback element arranged to receive the output signal and to convert the output signal into a second feedback signal.

A real-time power monitoring method executable by an electronic device, comprising: performing an ADC calibration operation to a voltage of a first battery of the electronic device; calculating and forming a diagonal line for the first battery; determining whether the comparison result between a gain and an offset and an optimum gain and an optimum offset is located with a preset error range; if the comparison result is located with the preset error range, determining that the voltage calibration for the first battery is successful; and, if the comparison result is located outside the preset error range, determining that the voltage calibration for the first battery is unsuccessful, analyzing and fixing the first battery and for re-performing the ADC calibration to the first battery.

A real-time power monitoring method executable by an electronic device, comprising: performing an ADC calibration operation to a voltage of a first battery of the electronic device; calculating and forming a diagonal line for the first battery; determining whether the comparison result between a gain and an offset and an optimum gain and an optimum offset is located with a preset error range; if the comparison result is located with the preset error range, determining that the voltage calibration for the first battery is successful; and, if the comparison result is located outside the preset error range, determining that the voltage calibration for the first battery is unsuccessful, analyzing and fixing the first battery and for re-performing the ADC calibration to the first battery.

An intermediate relay maloperation preventing device and method based on an improved recursive wavelet algorithm is provided. The device includes a power supply module, a voltage sampling circuit, an analog-to-digital conversion module, a DSP chip, and a relay maloperation signal shielding module. The voltage sampling circuit is connected to the analog-to-digital conversion module. The analog-to-digital conversion module is connected to the DSP chip. The DSP chip is connected to and controls a relay signal control module. The voltage sampling circuit collects a voltage. An improved recursive wavelet is used to extract a voltage feature. As such, identification of a fault signal and a normal signal is achieved, and real-time fault monitoring is accomplished. The detection method may be easily implemented, exhibits good filtering performance and anti-interference capability, delivers high detection accuracy, and may accomplish real-time online monitoring of intermediate relay faults.

The invention provides a testkey detection circuit, including a plurality of oscillators and a driving circuit. Each of the oscillators has an enable terminal, a voltage terminal and an output terminal, wherein the enable terminals are connected to a common enable terminal. The driving circuit receives the output terminals of the oscillators and increases a driving level of a selected one of the output terminals as a frequency output.

Detection and protection against electric power generator rotor turn-to-turn faults, rotor multi-point-to-ground faults, and rotor permanent magnet faults is provided herein. A fractional harmonic signal is used to determine the rotor fault condition. The fractional harmonic signal may be a fractional harmonic magnitude of the circulating current of one phase. The fractional harmonic may be a fractional harmonic magnitude of a neutral voltage. A tripping subsystem may issue a trip command based upon detection of a rotor turn-to-turn fault condition.

Detection and protection against electric power generator rotor turn-to-turn faults, rotor multi-point-to-ground faults, and rotor permanent magnet faults is provided herein. A fractional harmonic signal is used to determine the rotor fault condition. The fractional harmonic signal may be a fractional harmonic magnitude of the circulating current of one phase. The fractional harmonic may be a fractional harmonic magnitude of a neutral voltage. A tripping subsystem may issue a trip command based upon detection of a rotor turn-to-turn fault condition.

A packaged current sensor integrated circuit includes a primary conductor having an input portion and an output portion configured to carry a current to be measured by a magnetic sensing element supported by a semiconductor die adjacent to the primary conductor. The primary current path contains a mechanical locking feature. The thickness of the molded body of the package is reduced to improve vibration immunity.

A packaged current sensor integrated circuit includes a primary conductor having an input portion and an output portion configured to carry a current to be measured by a magnetic sensing element supported by a semiconductor die adjacent to the primary conductor. The primary current path contains a mechanical locking feature. The thickness of the molded body of the package is reduced to improve vibration immunity.

Mutual inductance-type current sensing apparatus (1) is described which includes a mutual inductance current sensor (11) having a first transfer function. The apparatus (1) also includes a low-pass filter (12) which receives a signal from the current sensor (11). The low-pass filter (12) has a second transfer function configured to attenuate one or more harmonic components of the signal. The apparatus (1) also includes an analogue-to-digital converter (13) which receives and digitises a filtered signal output from the low-pass filter. The apparatus (1) also includes a controller (8) configured to process a digitised signal from the analogue-to-digital converter (13) using a digital processing chain configured to compensate for the frequency and phase responses of the first transfer function and the second transfer function.