37 results about "Power line interference" patented technology

The invention relates to power-line communication interference devices and particularly relates to a plurality of devices which perform communication interference on facilities which use power lines for communication and belongs to the technical field of power-line communication, communication interference and interference resistance and information security. A device specifically includes a power-line interface, a DC power supply, a power-line coupling filter, a power amplifier and an interference signal generator. The invention also provides a power-line communication interference device with a power-line communication signal detection and analysis function, a processing and forwarding power-line communication interference device and a power-line communication signal short circuit / bypassing power-line communication interference device. The power-line communication interference devices are connected with power lines conveniently through forms of power-line insert ports, insert grooves and sockets and the like so that interference signals which interfere power-line communication are generated; an excellent interference effect is achieved through an extra-low interference power and electricity consumption quantity is low so that the power-line communication interference devices are especially suitable for being used in low-power-consumption inference application; and the interference mechanisms are simple in structure, low in realization cost and high in self-adaptive capability.

A pulse oximeter method and apparatus which provides (1) a notch filter at a distance between a modulation frequency and a common multiple of commonly used power line frequencies (50, 60, 100 and 120) and also (2) a demodulation frequency greater than a highest pulse rate of a person and lower than any harmonic of 50, 60, 100 or 120 Hz, to filter ambient light interference, while choosing an optimum demodulation frequency that avoids interference from the notch filter or from harmonics of the line interference. Also, ambient light for any low frequency interference, such as power line interference, is measured both before and after each of the light emitter wavelengths and the average of the ambient light is then subtracted from the detected signal.

Novel circuits for providing ride-through during unpredictable power line disturbances are disclosed in connection with low-power electronic devices. Such low-power electronics devices are typically subjected to undesirable lock-ups and reboots under momentary power line disturbances such as voltage sags, voltage swells, and other momentary line power disturbances. Diagnostics and visual indication are also integrated in the circuits to allow consumers to correlate equipment lock-up and malfunction with power disturbances, and to provide service providers with various analytics and historical data on the recorded disturbances. To reduce cost, the disclosed circuits utilize a simple DC capacitor without any additional power conditioning switches or converters. In one exemplary embodiment, the disclosed circuits are embedded inside a power line cord to provide a ride-through during the brief interval of time such power line disturbances occur.

A technique for real-time removal of power line interference (PLI) in electrocardiograms (ECG) with sampling rate a relevant integer multiple of the nominal power line frequency (NPLF), comprising band-pass PLI filtering of the ECG, determining expedient weights and weighted Least-Squares parabolic approximating downsampled to the NPLF series of band-pass PLI filtered values. The disclosed technique utilizes only integer arithmetic, includes pre-adjusting for the routine ECG sampling rates, causes negligible ringing and is still accurate in the common occurrences of PLI with deviating from the nominal 60 or 50 Hz frequency and varying amplitude.

The invention belongs to the technical field of neural information, relates to a method for extracting EEG signals, and specifically provides an extraction method for EEG signals in a magnetic resonance environment, which is used to improve the efficiency and accuracy of extracting weak EEG signals while retaining wide-band EEG signals. Electrical information, so that it can be widely used in clinical and scientific research; the invention first records the EEG signals without magnetic resonance interference, and then records the EEG signals in the magnetic resonance environment, and then uses two-stage adaptive noise cancellation to remove the magnetic resonance signals in turn. Gradient noise and power frequency interference, and finally a smoothing filter is used to remove high-frequency noise to obtain high-quality EEG signals. The invention can effectively remove magnetic resonance gradient noise, power frequency interference, and high-frequency noise of instruments, extract high-quality EEG signals, and greatly improve signal extraction efficiency and precision.