34 results about "Negative wave" patented technology

Disclosed herein is an abnormal current detection circuit for circuit breaker, comprising a full-wave amplifier, a positive wave-period comparator for comparing a positive wave-period amplification voltage signal with a positive wave-period reference voltage signal to output a pulse signal, a negative wave-period comparator for comparing a negative wave-period amplification voltage signal with a negative wave-period reference voltage signal to output a pulse signal, a combining circuit for combining pulse signals outputted from the positive wave-period comparator and the negative wave-period comparator to output a full-wave combining signal, a reference voltage generator for generating a reference voltage signal, and a comparative driving circuit section for comparing the combining signal with the reference voltage signal to output a signal for controlling a circuit breaker to be driven to a circuit breaking position when the combining signal is greater or equal to the reference voltage signal.

The invention provides a magnetic bias suppression system and method of a phase-shifted full bridge converter for photovoltaic power generation, and belongs to the technical field of power electronics. The input end of a primary side current detection circuit is electrically connected with a primary side of a high-frequency transformer, and the output end of the primary side current detection circuit is connected to an analog input interface of a CPU (central processing unit); the input end of each isolation drive circuit is respectively connected with corresponding output ends of the CPU; the CPU receives analog signals transmitted by a current conditioning circuit and converts the analog signals into digital signals through an A / D (analog-to-digital) converter; a computing unit of the CPU computes a duty ratio offset controlling a primary side current direct-current component through PI (proportion integral) regulation so that the primary side current direct-current component is zero; 0.5 is added as a duty ratio offset of the primary side direct-current component by a PWM (pulse width modulation) controller in the CPU to output a logic drive signal to the isolation drive circuits; and the isolation drive circuits control on and off of corresponding MOS (metal oxide semiconductor) pipes. According to the magnetic bias suppression system and method of the phase-shifted full bridge converter for the photovoltaic power generation, disclosed by the invention, positive wave and negative wave of the primary side output current are symmetric and the magnetic bias of the high-frequency transformer is effectively restrained.

The invention relates to a method for controlling a large-scale water delivery open channel gate based on the superposition wave absorbing principle. The method for controlling the large-scale water delivery open channel gate based on the superposition wave absorbing principle comprises the steps of calculating translation time of waves of translation, calculating the superposition time of positive waves of translation and negative waves of translation, determining the flow parameter of a water distributing opening, calculating the moment of adjustment of the opening degree of a regulator, calculating the adjustment value of the storage quantity of a channel, calculating the adjustment value of the flow of the regulator, calculating the actual opening degree of the regulator, executing the opening degree of the regulator, determining the back-adjusting time of the regulator, calculating the back-adjusting value of the flow of the regulator, calculating the back-adjusting plan of the opening degree of the regulator, and executing back-adjusting of the opening degree of the regulator. By the adoption of the method for controlling the large-scale water delivery open channel gate based on the superposition wave absorbing principle, the time and the water flow of water supply of the channel are matched with the time and the water flow of water use of the water distributing opening respectively, the water-level fluctuation at the position adjacent to the water distributing opening is obviously reduced, and therefore the possibility of the channel lining damage accident is reduced; in addition, the operation and management cost for monitoring, management and the like is reduced.

An alternating current drive method of a light-emitting diode and working voltage thereof. The alternating current drive method of a light-emitting diode includes: an alternating current obtaining step, obtaining alternating current sine wave signal with positive and negative waves; an electric power modulation step, modulating the alternating current sine wave signal obtained by the alternating current obtaining step based on impedance values of at least two mutually paralleled first and second light-emitting diode groups with opposite conducting directions, modulating the positive half cycle waveform of the alternating current sine wave signal into a positive half cycle drive signal conforming to the operating region of the first light-emitting diode group, and modulating the negative half cycle waveform of the alternating current sine wave signal into a negative half cycle drive signal conforming to the operating region of the first light-emitting diode group; and an electric power drive step, driving the first light emitting diode group by the positive half cycle drive signal of the above electric power modulation step, and driving the second light emitting diode group by the negative half cycle drive signal, wherein, the first and second group of light-emitting diodes are driven in sequence by the positive and negative half cycle drive signals.

The invention provides a defect detecting method for a weak joint of a diffusion welding joint interface, aiming at solving the problem that the defect on the weak joint cannot be judged by the traditional ultrasonic wave detecting method. The defect detecting method comprises the steps of analyzing information concealed in Fourier transform spectrum phase of a weak joint defect signal in a frequency domain, and reflecting positive and negative wave Fourier transform spectrum phases as reference by utilizing an unwelded lower surface of an upper-layer sample; by judging the differences and similarities between the positive and negative wave Fourier transform spectrum phases reflected by a joint interface of a diffusion welding sample and the positive and negative wave Fourier transform spectrum phases reflected by the unwelded lower surface of the upper-layer sample, extracting defect phase jump information of the weak joint, establishing a phase jump function, and judging the defect of the weak joint according to the criterion. According to the defect detecting method for the weak joint of the diffusion welding joint interface, the defect of the weak joint can be correctly judged, and the problem that an ultrasonic wave detection method is difficult to judge the defect only according to a time domain signal is solved.

The invention relates to a vertical high-speed impact testing machine capable of generating negative waves; guide pillars are oppositely arranged on a base of the testing machine, an impact table and a test bed are in clearance connection with the guide pillars, and interlocking structures are arranged on the impact table and the test bed; a lifting hydraulic cylinder is further arranged on the base, the upper end of the lifting hydraulic cylinder is connected with a release device, and the release device can be inserted into or separated from the test bed; a brake device is further arranged on the base, and the upper end of the brake device is connected with the impact table. According to the invention, a higher acceleration response peak value can be obtained, and the impact effect far exceeds that of a traditional impact testing machine; clearer impact negative waves with different pulse widths can be obtained; the generated impact vibration cannot be transmitted to a ground building; no hydraulic oil path is arranged on the test bench and the impact bench, and reliability and durability of the testing machine hydraulic system are improved.

The invention provides a single-ended traveling wave fault location method using positive and negative wave head time sequence intervals, which belongs to the technical field of power system relay protection. The method comprise the following steps of when lightning occurs on a power transmission line, and lightning points are not accordant with flashover points, detecting and recording current travelling wave data at a measuring end; judging the distribution situations of the lightning points and fault points on the power transmission line according to related characteristics of travelling wave, and resolving the modulus maximum of the current travelling wave data by using wavelet transform to obtain the travelling wave heads on a time axis; and calibrating the polarity and arrival moments of the travelling wave heads arriving at the measuring end, resolving multiple groups of fault distances through corresponding formulae by using a corresponding relation between a period (namely, the time sequence interval between adjacent wave heads) of wave heads of the same properties and a fault position, and averaging the multiple groups of fault distances to obtain a fault location result. The method has the advantages of reducing investment on location equipment, small location errors and the like.

The invention provides a defect detecting method for a weak joint of a diffusion welding joint interface, aiming at solving the problem that the defect on the weak joint cannot be judged by the traditional ultrasonic wave detecting method. The defect detecting method comprises the steps of analyzing information concealed in Fourier transform spectrum phase of a weak joint defect signal in a frequency domain, and reflecting positive and negative wave Fourier transform spectrum phases as reference by utilizing an unwelded lower surface of an upper-layer sample; by judging the differences and similarities between the positive and negative wave Fourier transform spectrum phases reflected by a joint interface of a diffusion welding sample and the positive and negative wave Fourier transform spectrum phases reflected by the unwelded lower surface of the upper-layer sample, extracting defect phase jump information of the weak joint, establishing a phase jump function, and judging the defect of the weak joint according to the criterion. According to the defect detecting method for the weak joint of the diffusion welding joint interface, the defect of the weak joint can be correctly judged, and the problem that an ultrasonic wave detection method is difficult to judge the defect only according to a time domain signal is solved.

The invention discloses an assessment method of auxiliary CRS-R scale auditory shock based on a brain-computer interface. The assessment method comprises following steps of: 1) selecting simulation, arranging and designing an experimental paradigm; 2), collecting signals; 3) performing data processing; 4) counting inspecting evaluation standards. The assessment method of auxiliary CRS-R scale auditory shock based on the brain-computer interface has following beneficial effects: based on an auditory extraneous experimental paradigm, mismatch negative waves MMN and P300, peculiar to human race, are induced; in combination with an auditory shock assessment method of a coma recovery scale CRS-R, scores of CRS-R auditory shock items are accessed by adoption of the brain-computer interface and a peak detection algorithm; and therefore, the method can not only be effectively used for assessment diagnoses of the coma recovery scale, tracking of recovery effect and selections of a prognosis treatment scheme but also provide scientific and objective detection data to the conventional scale diagnoses in order to ensure authenticity and effectiveness of detection results..

The invention discloses a control circuit provided with positive and negative wave independent dead zone control elements, and relates to a high-frequency switching power supply circuit. The control circuit is mainly composed of a NOT gate circuit, resistors, capacitors and diodes, wherein the NOT gate circuit comprises an oscillation gate, an inverting gate, delay gates and output gates, an output end of the oscillation gate is connected to a first isolation resistor, an input end of the inverting gate, a second discharge resistor and a second dead zone control resistor, the first isolation resistor is connected to an input end of a first output gate, and an output end of the first output gate is connected to a negative half-cycle signal output end through a first output resistor; an output end of the inverting gate is connected to a first discharge resistor, a first dead zone control resistor and a second isolation resistor, the second isolation resistor is connected to an input end of a second output gate, and an output end of the second output gate is connected to a positive half-cycle signal output end through a second output resistor. According to the invention, dead zone control element of the positive half cycle and the dead zone control element of the negative half cycle are mutually independent, a trailing phenomenon of positive half-cycle signals and negative half-cycle signal in inversion is eliminated, and the efficiency of a switching power supply is enabled to be higher.

The invention discloses a signal processing device used for diagnosing a piece of gas insulated equipment, which can flexibly deal with various changes of processing conditions when predetermined signal processing rules can not be fully used for dealing with the requirements of information processing. The signal processing device used for diagnosing the gas insulated equipment is provided with a sensor component 2 that decomposes partial electromagnetic wave signals which are transmitted in the detected gas insulated equipment and detected by a discharging sensor 1 into a plurality of characteristic quantities corresponding to various physical quantities expressed by signal waveforms and collects the characteristic quantities. The characteristic quantities collected by the sensor assembly2 are a first positive wave crest value A, a first negative wave crest value B, the half-value width Delta T of the first wave crest value, the envelope waveform y of a high-frequency signal, a decaytime constant T of the high-frequency signal, pulse interval information Delta T of partial discharged signals and pulse density N.

The invention relates to a discharge circuit of an electrosparking power supply. The discharge circuit comprises a working power supply, a charge power supply and a discharge circuit branch consisting of an electrode and a connection terminal of a workpiece, and also comprises a deionization circuit branch, a negative wave absorption circuit branch and an exploding capacitor circuit branch, wherein an electrode end of the discharge circuit branch is connected with a positive output end of the working power supply, the connection terminal of the workpiece is connected with a negative output end of the working power supply, and the exploding capacitor circuit branch consists of a capacitive unit and a capacitor discharge switch that are connected in series, the capacitor discharge switch and a capacitor charge switch are both a power field effect transistor or an insulated-gate bipolar transistor, and an electronic switch is a power field effect transistor or an insulated-gate bipolar transistor. The discharge circuit can immensely shorten the setup time of an electric field, and improve processing time, simultaneously the quality of processed surface and also the deionization capacity.

Disposed herein is an abnormal current detection circuit for circuit breaker, comprising a full-wave amplifier 202, a positive wave-period comparator 203 for comparing a positive wave-period amplification voltage signal with a positive wave-period reference voltage signal to output a pulse signal, a negative wave-period comparator 204 for comparing a negative wave-period amplification voltage signal with a negative wave-period reference voltage signal to output a pulse signal, a combining circuit 206 for combining pulse signals outputted from the positive wave-period comparator and the negative wave-period comparator to output a full-wave combining signal, a reference voltage generator 209 for generating a reference voltage signal, and a comparative driving circuit section 208 for comparing the combining signal with the reference voltage signal to output a signal for controlling a circuit breaker to be driven to a circuit breaking position when the combining signal is greater or equal to the reference voltage signal.

The invention discloses an electrocardiosignal (ECG) data analysis method suitable for a mobile platform. The electrocardiosignal (ECG) data analysis method includes subjecting collected electrocardiosignal data to original ECG electrocardiosignal median filtering; detecting and positioning an R wave through a self-adaption dual-threshold algorithm; detecting two forward waves before and after the R wave, wherein the two forward waves are a P wave and a T wave; detecting two negative waves on two sides of the R wave, wherein the two negative waves are a Q wave and an S wave; using starting point and terminal point positions of the R wave, the P wave, the T wave, the Q wave, and the S wave to calculate ECG feature values of wave point intervals for arrhythmia diagnosis. According to the ECG data analysis method suitable for the mobile platform, the accuracy for detection of arrhythmia can reach over 92%; since an algorithm structure is concise, processing efficiency is high, only 12s is required for processing one-minute ECG data on a Cortex A8 / Android mobile platform, and the method is suitable for developing a mobile platform based portable admeasuring apparatus.

The invention discloses an oil pipeline leakage detection and positioning method based on comprehensive signals. The method oil pipeline leakage detection and positioning method based on comprehensive signals can solve the problems that a single pressure signal is limited by pipeline tail end devices and can hardly detect the pressure inflection point and under the conditions of small leakage and slow leakage, inflection point features of the pressure signal are not prominent in a negative wave pressure method. According to the technical scheme, pressure signals and flow signals in the leakage transient process are combined into new comprehensive signals and variation of the comprehensive signals is monitored. Whether leakage exists or not is judged according to existence of abnormities and leakage position calculation is carried out by recognizing the comprehensive signals. Compared with the negative wave method, limitation by devices at the two ends of the pipeline does not exist and the oil pipeline leakage detection and positioning method is especially suitable for working conditions that oil tanks are arranged at the tail ends of the pipeline and the like. As the comprehensive signals are adopted, the inflection point features of the leakage signal can be effectively highlighted and the oil pipeline leakage detection and positioning method is also suitable for detection and positioning of small leakage and slow leakage.