An arc fault detection system senses current flow in a power source branch and in one or more load branches in an electrical system. Over a frequency range divided into a predetermined number of frequency bins, a controller records and tallies the branch having largest magnitude of power spectral density for each frequency bin. The branch having highest total tally is determined to be the branch in which the arc fault occurred and can then safely be isolated from the electrical system.

An environmental frequency sensing device, includes logic that performs signal strength (SS) level separation on a received band of frequencies to produce SS level separated frequencies. The logic performs frequency grouping on the SS level separated frequencies for each signal strength level to produce magnitude information for each grouping. The logic generates peak data by detecting peaks of the produced magnitude information. The logic generates an edge event indicating a signal edge based on arrival or departure of a given peak and compares, on a frequency basis, generated edges to stored fingerprint data of a signal of interest. Based on the comparison, the logic provides detected signal data indicating current use of a range of frequencies in an environment.

An environmental frequency sensing device, includes logic that performs signal strength (SS) level separation on a received band of frequencies to produce SS level separated frequencies. The logic performs frequency grouping on the SS level separated frequencies for each signal strength level to produce magnitude information for each grouping. The logic generates peak data by detecting peaks of the produced magnitude information. The logic generates an edge event indicating a signal edge based on arrival or departure of a given peak and compares, on a frequency basis, generated edges to stored fingerprint data of a signal of interest. Based on the comparison, the logic provides detected signal data indicating current use of a range of frequencies in an environment.

A method for processing an initial signal includes a useful signal and added noise, which comprises a step of frequency selective analysis providing starting from initial signal a plurality of wideband analysis signals corresponding to one of the analysed frequencies, and comprising the following actions: zero or more complex frequency translations, one or more undersampling operations, computation of the instantaneous Amplitude, of the instantaneous Phase, and of the instantaneous Frequency of the wideband analysis signals. This information then allow to detect modulations of signals included in high levels of noise and to detect with a good probability the presence of a signal in a high level of noise.

Disclosed herein are a method for analyzing heavy metal removal efficiency using phase difference analysis and an apparatus using the method. The method for analyzing heavy metal removal efficiency using phase difference analysis includes applying a magnetic field to a magnetite onto which a heavy metal is adsorbed, based on a first solenoid coil and a second solenoid coil that have an identical winding direction, applying a high-frequency signal to the magnetite, based on a third solenoid coil having a winding direction that differs from that of the first solenoid coil and the second solenoid coil, detecting a high-frequency signal transformed by the magnetite, and calculating a phase difference between a previously detected default high-frequency signal and the transformed high-frequency signal, and analyzing an efficiency of heavy metal removal by the magnetite by measuring a concentration of the heavy metal based on the phase difference.

A method for generating an electrochemical impedance spectrum for a battery includes: collecting, in a discharge state of a battery, battery discharge information of the battery periodically according to a preset collection interval, where the battery discharge information includes collection time, and current information and voltage information associated with the collection time; performing Fourier transform according to the collection interval and battery discharge information, to obtain multiple frequency-based first battery signals; determining a second battery signal from the multiple first battery signals, where the second battery signal includes a voltage signal greater than or equal to a preset voltage threshold; and determining an electrochemical impedance at a corresponding frequency according to the second battery signal, and constructing an electrochemical impedance spectrum according to all the electrochemical impedance.

A method for generating an electrochemical impedance spectrum for a battery includes: collecting, in a discharge state of a battery, battery discharge information of the battery periodically according to a preset collection interval, where the battery discharge information includes collection time, and current information and voltage information associated with the collection time; performing Fourier transform according to the collection interval and battery discharge information, to obtain multiple frequency-based first battery signals; determining a second battery signal from the multiple first battery signals, where the second battery signal includes a voltage signal greater than or equal to a preset voltage threshold; and determining an electrochemical impedance at a corresponding frequency according to the second battery signal, and constructing an electrochemical impedance spectrum according to all the electrochemical impedance.

Measurement apparatus and method for digital data acquisition. A first operation mode is provided for real-time processing of digital data having a reduced sample rate or resolution. Furthermore, a second operation mode is provided for processing the measurement signal off-line with a higher accuracy. In particular, the high accuracy data may be temporarily stored and analyzed upon the operation mode is changed from the real-time mode to the off-line mode.

Measurement apparatus and method for digital data acquisition. A first operation mode is provided for real-time processing of digital data having a reduced sample rate or resolution. Furthermore, a second operation mode is provided for processing the measurement signal off-line with a higher accuracy. In particular, the high accuracy data may be temporarily stored and analyzed upon the operation mode is changed from the real-time mode to the off-line mode.

A composite analog-to-digital converter (ADC) has a low resolution ADC configured to receive and digitize analog data, the low resolution ADC having a low resolution and a high operating speed, one or more high resolution ADCs configured to receive and digitize the analog data, the one or more high resolution ADCs having a resolution higher than the low resolution ADC, and an operating speed lower than the high operating speed of the low resolution ADC, a sample clock generator to provide a sample clock signal to the low resolution ADC and to a clock divider, a mixer to receive the analog data and connected to the one or more high resolution ADCs, a local oscillator connected to the mixer to allow the one or more high resolution ADCs to be tuned to sample a portion of a spectrum of the first ADC. A test and measurement instrument contains a composite ADC. A method of operating a composite analog-to-digital converter (ADC), includes receiving an analog signal at a low resolution ADC that operates at a high speed, receiving the analog signal at one or more high resolution ADCs that operate at a resolution higher than the low resolution ADC and at a lower speed than the operating speed of the low resolution ADC, tuning the high resolution ADC to phase align and time align a signal path for the one or more high resolution ADCs to the signal path for the low resolution ADC, producing a spectrum from the low resolution ADC, and producing a portion of the spectrum from the one or more high resolution ADCs.