46results about How to "Suppression of high frequency interference" patented technology

The invention relates to a method and a system for randomly switching alternating current. The system comprises a voltage detecting circuit, a current detecting circuit, a first switching circuit, a second switching circuit, a control circuit, a pulse width modulator (PWM) and an APFC circuit, wherein the first switching circuit is used for switching on or off a main power supply; the second switching circuit is used for switching on or off a reserve power supply; the control circuit is used for controlling the first switching circuit and the second switching circuit to switch on or off and transmitting a pulse signal to the PWM; the PWM is used for modulating an output dutyfactor according to the pulse signal transmitted by the control circuit; the APFC circuit is used for receiving the output dutyfactor of the PMW so as to control the output current, and thereby the linear rectification of the output current is realized to ensure the synchronization of the output voltage and the current phase of the APFC circuit. The state of the power supply can be automatically recognized by adopting the random switching so as to adapt to power supplies in different environments, and the switching time is greatly reduced and fixed. The current linear rectification can be randomly switched as alternating current to solve the peak interference brought by the random switching, and the power compensation is carried out to realize the minimum loss of circuit power.

The invention discloses a differential piezoelectric digital geophone. The differential piezoelectric digital geophone comprises a geophone core which comprises a cylindrical shielding case, a base, piezoelectric elements, mass blocks, a signal conditioning unit, a signal preprocessing unit, feed-through capacitors and outgoing cables. The base is arranged in the center of the shielding case and in rigid connection with the shielding case; the two groups of piezoelectric elements are symmetrically attached to two sides of the base, and the two mass blocks are symmetrically attached to the outer sides of one group of piezoelectric elements; the two groups of piezoelectric elements are connected with an input end of the signal conditioning unit through outgaining electrodes at two ends of the piezoelectric elements, an output end of the signal conditioning unit is connected with an input end of the signal processing unit, and an output end of the signal processing unit is connected with the outgaining cables through the feed-through capacitors. By means of the geophone core in the symmetrical structure, differential signal output and direct digital processing of signals, the differential piezoelectric digital geophone has the advantages of high flexibility, high antijamming capability, wide dynamic range, portability, durability and the like.

The invention discloses a radio frequency amplitude keying demodulation circuit with large input dynamic range, which comprises an amplitude detection circuit, a Gaussian filter circuit, a peak detection circuit and two branches of difference amplitude keying demodulation circuits of a comparison circuit. The amplitude detection circuit is formed by a fixed gain amplifier with S poles in series connection and an amplitude detection and conversion circuit. Each branch of the amplitude keying demodulation circuits includes that input signals are amplified to i fuzzy amplitude keying signals through the amplitude detection circuit, the i fuzzy amplitude keying signals are added and converted into high-low voltage amplitude signals, high frequency components are filtered through the Gaussian filter circuit, the filtered signals pass through the peak detection circuit to obtain high-low average amplitude signals, and the average amplitude signals and the signals filtered by the Gaussian filter circuit are compared through the comparison circuit to obtain demodulation signals output by the radio frequency amplitude keying demodulation circuit. The radio frequency amplitude keying demodulation circuit with the large input dynamic range can be flexibly used for demodulating amplitude detection signals with modulation degree ranging from 0.5 to 0.9, thereby being capable of being applied to the front end of a radio frequency receiver with input signals reaching up to 60dB dynamic range.

The invention relates to a multi-sensor data fused aviation coil inertial navigation device, wherein the upper end of a suspending rope is tied on the bottom of a single rotor unmanned helicopter, the lower end of the suspending rope is tied on a cross-shaped support in an equal angle, the cross-shaped support supports a Z-component receiving coil, and three altitude sensors are equidistantly fixed on the Z-component receiving coil and are connected with a posture data recording system through signal transmission lines; each posture sensor consists of an MEMS three-axis gyroscope, an MEMS three-axis accelerometer and an MEMS three-axis magnetoresistive sensor. According to the multi-sensor data fused aviation coil inertial navigation device, the measurement on an air posture deflection angle of an aviation coil is realized; the multi-sensor data fused aviation coil inertial navigation device has the characteristics of small size, quick response and low cost; in addition, after performing the data fusion processing, the influence on swinging posture of the aviation coil in the environment can be effectively reduced, and the corrected inversion magnetic field data can meet the precision requirement of a system at a strongly swinging environment.

The invention discloses a partial discharge signal processing method considering pulse extraction and signal denoising and a partial discharge positioning method for a power cable. The partial discharge signal processing method adopts a data processing order of ''first extraction, then denoising'', comprises the following steps of: decomposing a singular value, and comparing the optimal singular threshold with the largest singular value to realize a fast and precise positioning of a partial discharge pulse; extracting the partial discharge pulse; and denoising the extracted partial discharge pulse signal by refactoring the singular value. The partial discharge signal processing method considering pulse extraction and signal denoising and the partial discharge positioning method for the power cable can effectively suppress the white noise of the white regeneration of the partial discharge signal under lower SNR conditions based on the decomposition-reconstruction method of the singularvalue, and can suppress high-frequency interference by the denoising combining with a layer of discrete wavelet. Based on the partial discharge signal processing method described above, the partial discharge pulse is extracted, and the precise positioning of the partial discharge source (the partial discharge point) of the power cable can be realized.

The invention relates to a detection method for an output signal of a part of an automobile and a circuit thereof, in particular to a detection method for an output signal of a vehicle wheel speed sensor and a circuit thereof. A sensor signal is divided into a public end and a signal end, wherein the public end sets the public comparison end voltage to be 1/2 of mains voltage by a resistance partial voltage way; the signal end is connected with an adjustable resistor over the ground, and the adjustable resistor is used for load output; sensors of different types are adapted by changing the adjustable resistor; and a sine wave or square wave output by the wheel speed sensor is shaped into a standard square wave through comparing the 1/2 of mains voltage with the signal of the wheel speed sensor by a comparator. The invention is applied to an anti-skid brake system (ABS)/traffic control station (TCS)/electronic stability program (ESP) system of the automobile, can detect not only the signal of a magnetoelectric wheel speed sensor, but also the signal of a Hall type sensor.

The invention provides a highly flexible non-twisting control cable, and belongs to the technical field of cables. The cable comprises a left and right bi-directionally twisted cable core; a foamed polyethylene buffer layer is externally extruded and covered on the cable core, a tin-plated copper band shielding layer wraps the foamed polyethylene buffer layer, and an external protection layer is externally extruded and covered on the tin-plated copper band shielding layer; the cable core comprises four groups of wire cores, filling materials and a PP lapping band, wherein the PP lapping band wraps the four groups of wire cores and the filling materials; and the cable core also comprises a conductor and a crosslinking polyethylene insulation layer externally extruded and covered on the conductor. The cable has the advantages of high electric performance, shielding performance, mechanical properties such as tensile property and twisting resistance, thermal resistance and ageing resistance, environmental resistance, chemical corrosion resistance and fire resistance, convenient use, no limitation of laying drop heights and the like; and the cable can be laid in fixed places, such as rooms, tunnels, cable trenches and tubes, where the shielding requirements are high, and the cable can be widely used and has better social and economic benefits.

The invention discloses a high-voltage electric energy metering cabinet and a method based on real-time monitoring. A primary device voltage transformer and a current transformer are arranged at a high-voltage switch load side, and power of an electric energy meter and power of an acquisition terminal are provided by a secondary side of the voltage transformer; two voltage transformers are arranged at a high-voltage switch power side; the voltage transformers are connected with a voltage detection circuit; the current transformer is connected with a current detection circuit; a circuit where the high-voltage switch is is connected with a temperature detection circuit; the voltage detection circuit, the current detection circuit and the temperature detection circuit are all connected with a controller; and the controller uploads acquired data to an information acquisition main station. Through monitoring current, voltage and temperature when the high-voltage electric energy metering cabinet works in real time, real-time monitoring on the working state of the intelligent electric meter is realized; and when the intelligent electric meter fails, warning is timely carried out, and corresponding handling and adjustment are carried out.

The invention relates to a wide-range alternating current signal zero-cross detection method and device and belongs to the technical field of electronics. The wide-range alternating current signal zero-cross detection device comprises a rectification unit, a conversion unit, an amplification unit, a comparison unit and an output unit. For current type detection and voltage type detection, different conversion units and amplification units are designed. The conversion unit designed by the invention is used for achieving wide-range voltage zero-cross detection. According to the invention, no step-down circuit or voltage stabilization amplitude limiting circuit is adopted, direct processing of high voltage signals is conducted, influences of background noise or voltage thresholds on detection precision are reduced, zero-cross detection of large signals and small signals can be achieved at the same time, the precision is high, and wide practical value is achieved.

The invention discloses a speech recognition circuit and a translation system, wherein the speech recognition circuit includes a circuit board, and further includes a microphone array, a speech recognition module, a microprocessor module, an audio channel, which are arranged on the circuit board and connected in sequence. The amplifier module and the speaker also include a voltage divider module connected to the voice recognition module. There are several control input terminals on the voice recognition module. The voltage division branch is composed of several resistors connected in series, and each control input terminal is connected to each voltage division branch respectively. A voice recognition circuit of the present invention has low cost, and can realize voice recognition range and noise reduction effect dynamic balance.

The invention relates to a filter circuit of an ion source driving power supply and a filter parameter detection method and device thereof, and the filter circuit of the ion source driving power supply is an LC filter circuit, is connected in series between the ion source driving power supply and an ion source load, and comprises inductors connected in series and filter capacitors connected in parallel; the filter circuit is used for suppressing high-frequency oscillation of the real-time current waveform output by the ion source driving power supply and filtering out a high-frequency oscillation interference signal in the real-time current waveform. According to the technical scheme provided by the invention, the LC filter circuit of the high-frequency filter element, the series inductorand the parallel filter capacitor are adopted, so when the ion source driving power supply outputs power, the filter circuit can ensure that the ion source driving power supply outputs smooth direct-current voltage, high-frequency interference caused by instability in ion source load is filtered out, and the power supply is prevented from being damaged.

The invention discloses a ship power grid parameter real-time monitoring system and method. The ship power grid parameter real-time monitoring system includes a signal conditioning unit, a data acquisition unit, a data processing unit, a communication interface circuit, an external expansion memory, and a frequency detection module, wherein the signal conditioning unit comprises a resistor dividernetwork, a current transformer, and a low-pass filter; and the low-pass filter is arranged between the resistor divider network and the data acquisition unit or between the current transformer and the data acquisition unit. The ship power grid parameter real-time monitoring system effectively converts the energy of a bicycle brake into electrical energy. The ship power grid parameter real-time monitoring system introduces the low-pass filter LPF before sampling, thus filtering the spectral components higher than the sampling frequency in the continuous signal so as to reduce the possibility of spectrum aliasing, ensuring that the basic spectrum of the sampling signal maximally approaches to the spectrum of the original continuous signal, effectively filtering high frequency interference and avoiding sampling effects caused by harmonic pollution.

The invention relates to the technical field of amplifying circuits. The invention provides a weak pulse signal amplification circuit and a tiny dust detector. The circuit comprises an input capacitor, an impact sensor, a charge-sensitive pre-amplification sub-circuit and a charge-sensitive post-amplification sub-circuit. The input capacitor and the impact sensor are electrically connected with the input end of the charge-sensitive pre-amplification sub-circuit; the charge-sensitive post-amplification sub-circuit and the charge-sensitive pre-amplification sub-circuit are cascaded to form a charge-sensitive amplification sub-circuit; the amplification factor of the charge-sensitive amplification sub-circuit is multiplied; the signal amplification capability of the charge-sensitive amplification sub-circuit is improved; when the impact sensor is in an idle state, the input capacitor is utilized to test the adaptation of the charge-sensitive amplification sub-circuit and the impact sensor, and when the impact sensor is in a detection state, the input capacitor prevents the performance of outputting a weak charge pulse signal to the charge-sensitive amplification sub-circuit so as to prevent the input capacitor from generating signal interference on the impact sensor.

The present invention proposes a heart rate meter, including a signal acquisition circuit, a filter circuit, an operational amplifier circuit, a processing module U4, and a display module U3; the signal acquisition circuit includes an infrared emitting tube D1, an infrared receiving tube Q1, and a resistor R1; the filter circuit includes a resistor R2 , R3, capacitors C1, C2, and C3; the operational amplifier circuit includes operational amplifier U1, operational amplifier U2, resistors R4, R5, R6, R7, capacitors C4, C5, and C6; the processing module U4 is a PIC16F84 microcontroller; the display module U3 is an LCD1602 Display modules. Compared with the prior art, the advantages and positive effects of the present invention are: the circuit structure is simple, the response is fast, the cost is low, the operation is stable, the heart rate of the subject can be measured quickly and conveniently at low cost, and it is easy to carry; The integrated anti-interference structure can filter out most of the high-frequency interference and ensure the reliability of the measurement results.

The invention provides a filtering connector assembly and an automobile. The filtering connector assembly comprises a shell, at least two conductive center shafts and feed-through capacitors, the shell is made of conductive materials, a containing cavity is formed in the shell, at least part of each conductive center shaft is arranged in the containing cavity, the conductive center shafts are fixedly connected with the shell and insulated from the shell, two ends of each conductive center shaft are exposed by two opposite openings, a first connecting structure is arranged at a first end, exposed by one opening, of each conductive center shaft, a second connecting structure is arranged at a second end, exposed by the other opening, of each conductive center shaft, and one feed-through capacitor penetrates the corresponding conductive center shaft. When the filtering connector assembly is used in a high-voltage circuit, a high-frequency filtering circuit can be formed by the aid of the equivalent inductance of a long cable at high frequency, and high-frequency interference of a high-voltage cable harness is obviously inhibited.