17 results about "Negative peak" patented technology

A method comprising: generating, by a peak detector, a comparison signal by comparing a coil current of a relay against a dynamic threshold, the comparison signal having a first value when the coil current is above the dynamic threshold, the comparison signal having a second value when the coil current is below the dynamic threshold, wherein the peak detector is configured to: cause the dynamic threshold to track the coil current until a positive peak in the coil current is reached that has a value PP, and set the dynamic threshold to a rebound value R in response to detecting that a negative peak in the coil current is reached, the rebound value R being based on the value PP; detecting whether the relay is in a faulty state based on the comparison signal; and generating an indication of a fault when the relay is in a faulty state.

The invention relates to a resonant hybrid flyback converter (1). The converter comprises an input capacitor (102) and an output capacitor (111); a high-side, HS, switch (104, Q 1 ) and a low-side, LS, switch (105, Q 2 ); a transformer, comprising a primary winding (106, L r ; 108, L m ) and a secondary winding (109); and a rectifying circuit (110, D). The input capacitor (102), the HS switch (104, Q 1 ) and the LS switch (105, Q 2 ) form a first circuit loop, the LS switch (105, Q 2 ), the primary winding (106, L r ; 108, L m ) and the resonant capacitor (107, C r ) form a second circuit loop; and the rectifying circuit (110, D), the secondary winding (109) and the output capacitor (111) form a third circuit loop. The converter (1) further comprises a first sensing circuit, configured to sense a primary current (304, I HB ) through the primary winding (106, L r ; 108, L m ) and the resonant capacitor (107, C r ); a second sensing circuit, configured to sense a secondary current (307, I SEC ) through the rectifying circuit (110, D) and the secondary winding (109); and a control circuit (103). The control circuit (103) is configured to determine a positive peak value (305, I MAGpos ) for the primary current (304, I HB ) in accordance with a closed-loop control of an average of the secondary current (307, I SEC ) and a setpoint value (I SECref ) for said average; determine a negative peak value (306, I MAGneg ) for the primary current (304, I HB ) in accordance with a current-limited and voltage-limited commutation of the switches (104, Q 1 ; 105, Q 2 ); derive a blanking signal (308) that temporally covers a non-zero secondary current (307, I SEC ) period; and drive the switches (104, Q 1 ; 105, Q 2 ) in turns in accordance with a dead time (t dead ) for the commutation of the switches (104, Q 1 ; 105, Q 2 ), and a hysteretic control of the primary current (304, I HB ) between the positive peak value (305, I MAGpos ) and the negative peak value (306, I MAGneg ). The hysteretic control is inhibited by the blanking signal (308). The use of the blanking signal enables a hysteretic control of resonant hybrid flyback converters irrespective of the particular load condition.

The present disclosure relates to a heating device and a detection method thereof. The heating device comprises: a resonance circuit comprising an inverter circuit and a resonance tank; the inverter circuit provides a resonance tank current and a resonance tank voltage; the resonance tank comprises a heating coil, a resonance tank capacitance, a resonance tank equivalent inductance and a resonance tank equivalent resistance; a detection unit detects a capacitance voltage of the resonance tank capacitance to obtain a reference voltage value, a first zero-crossing time point, a second zero-crossing time point, a time variation, a resonance period and a negative peak voltage value of the capacitance voltage; and a control unit; wherein the detection unit calculates an inductance value of the resonance tank equivalent inductance according to the capacitance voltage of the resonance tank capacitance, the resonance period and a first calculation formula; and calculates a resistance value of the resonance tank equivalent resistance according to the resonance tank equivalent inductance, the time variation, the resonance period, the reference voltage value and the negative peak voltage value and a second calculation formula.

The application discloses a centering method of a spiral scanning measurement system, comprising a rotating platform, an x-direction driving platform and a y-direction driving platform for driving the rotating platform, and a probe, wherein the centering is performed according to the following steps: S01, placing a scale sheet in the center of the rotating platform; S02, moving the probe to the center of the rotating platform, so that the scale sheet is in the measurement range of the probe, and the z-axis height value h of the scale sheet is set as 0; S03, starting the rotating platform, and recording the total number N of positive and negative peak values of the signal sent by the probe when the rotating platform rotates one round; and S04, under the condition that the rotating platform continues to rotate, adjusting the x-direction driving platform and the y-direction driving platform to make N tend to 0, and completing the centering of the driving rotating platform. The scale sheet is taken as a measured object, the eccentricity error r is reflected through the scale sheet, and the centering is realized by gradually eliminating the zero-crossing number N.

A horn apparatus for a vehicle is provided. The horn apparatus is configured to produce an audible warning sound having a fundamental frequency. The horn apparatus comprises a signal unit configured to provide a signal; and a loudspeaker configured to produce an audible warning sound based on the signal provided by the signal unit. A signal, as provided by the signal unit, is also provided. The signal is defined by a waveform that alternates between a positive peak and a negative peak of the waveform multiple times within a period corresponding to the fundamental frequency of the warning sound. A time between each alternation of the waveform varies across the period. A method of providing a signal for use by the horn apparatuses to produce an audible warning sound is also provided. The method comprises providing a waveform that defines the signal and providing the signal defined by the waveform. Computer-readable media and computer program products are provided that comprise logic and / or instructions that, when executed by a computer / processor, cause the computer / processor to carry out the methods described herein.

A method of performing a circuit opening and closing operation in a power system including three phases, a three-phase transformer, and a circuit breaker system, the method including a) opening all three phases simultaneously such that a reference current of a reference phase is interrupted first at a first current zero crossing after the opening; and b) closing all three phases simultaneously at a phase to ground voltage of the phase lagging the reference phase by 120°, in a time range of ±90° from a negative peak of said phase to ground voltage if the current zero crossing is a positive current zero crossing, or in a time range of ±90° from a positive peak of said phase to ground voltage if the current zero crossing is a negative current zero crossing.

The application provides a processing circuit of a float flowmeter converter, a collection and amplification module collects and amplifies a signal voltage to obtain an amplified voltage; a bias collection module receives the amplified voltage, collects the amplified voltage to obtain a positive peak value of the amplified voltage and a negative peak value of the amplified voltage, performs proportional subtraction operation on the positive peak value and the negative peak value to obtain a bias value of the amplified voltage; an amplitude collection module receives the amplified voltage and the bias value, performs subtraction operation on the amplified voltage and the bias value to obtain a corrected amplified voltage, the corrected amplified voltage is the amplified voltage without bias, collects the corrected amplified voltage to obtain an amplitude of the corrected amplified voltage. The application processes the signal voltage related to the magnetic displacement of the float flowmeter, collects the bias value and the amplitude of the signal voltage, eliminates the bias value of the signal voltage, and obtains the accurate signal voltage amplitude and bias value, thereby improving the accuracy and precision of subsequent flow calculation.

The application discloses a turn ratio optimization method of integrated three-phase Boost-LLC topology, comprising the following steps: obtaining a positive peak value and a negative peak value of a Boost chopper inductance current; obtaining an effective value of the chopper inductance current according to the positive peak value and the negative peak value; obtaining resonance current peak values of a Boost primary side and a secondary side; obtaining resonance current effective values of the primary side and the secondary side according to the resonance current peak values; calculating inductance values under different turn ratios when an output voltage is fixed; and obtaining a turn ratio with minimum loss according to the effective value of the chopper inductance current, the resonance current effective values and the inductance values under different turn ratios. The application solves the problem that the turn ratio in the integrated three-phase Boost-LLC topology is difficult to be scientifically and efficiently designed.

The application discloses a kind of neural network-based direct current transmission line fault location method, device and medium.Therein, method includes: detect whether the fault of direct current line occurs, and in the case where the fault of direct current line is detected, store the single-ended voltage sampling value in the predetermined time period before and after direct current line fault;Distinguish whether the negative pole fault of direct current line occurs, in the case where the fault of direct current line is negative pole fault, single-ended voltage sampling value is multiplied-1;Single-ended voltage sampling value is smoothed, and voltage smooth sampling value is determined;According to voltage smooth sampling value, extract the first negative peak time, the first negative peak and delay time during direct current line fault;The first negative peak time, the first negative peak and delay time are input into the regression neural network model constructed in advance, and the predicted fault position of direct current transmission line is output.

This application discloses a circuit and its control method for enhancing the input impedance of a chopper amplifier. The circuit includes an OTA operational amplifier module, a chopper module, an input capacitor, a feedback capacitor, a peak detector, a valley detector, a subtractor, a comparator integrator, and a variable capacitor. The method includes: acquiring a differential input signal and performing chopping and amplification processing to obtain an output signal; performing peak detection processing to obtain positive and negative peak voltages; performing subtraction calculations to obtain the peak-to-peak value of the OTA signal; performing integration and ripple filtering processing to obtain a DC voltage signal with amplitude information; converting it into a DC current signal with amplitude information, and performing current compensation on the differential input signal through a positive feedback loop. The embodiments of this application can accurately compensate for on-chip parasitic capacitances, thereby avoiding current draw from the signal source and enhancing the input impedance of the chopper capacitor-coupled instrumentation amplifier. This application can be widely applied in the field of analog integrated circuit design technology.

Provided is an electromagnetic wave absorber which is capable of satisfactorily absorbing electromagnetic waves having a high frequency of at least a millimeter band, and which is also capable of satisfactorily absorbing electromagnetic waves having a desired frequency even when the ambient temperature changes. An electromagnetic wave absorber in which a magnetoplumbite-type hexagonal ferrite (1a) that performs magnetic resonance in a millimeter-band frequency band is contained in a binder (1b), said electromagnetic wave absorber being characterized in that: a part of metal sites of the magnetoplumbite-type hexagonal ferrite are substituted by La; in a graph representing the relationship between the frequency of the incident electromagnetic wave and the value of the imaginary part of the complex number relative permeability of the electromagnetic wave absorber, when the temperature of the electromagnetic wave absorber changes from 25 DEG C to 105 DEG C, the value of the frequency that becomes a positive peak shows a positive rate of change, and the value of the frequency that becomes a negative peak shows a positive rate of change. The ratio of the amount of change in the frequency of a positive peak when changed from 25 DEG C to 105 DEG C to the value of the frequency of a positive peak at 25 DEG C is 1.5% or less.

The application discloses a laser Doppler impact test signal demodulation method, and belongs to the field of impact test signal processing.The application realizes the method as follows: the laser Doppler signal is subjected to CEEMD processing to obtain each IMF component and residual; the data outside the predetermined range of the IMF component is set to zero, and the CEEMD processing result is obtained by adding the processed IMF component and the residual; the determination threshold is obtained according to the peak value of the CEEMD processing result, and the cross-threshold zero point is obtained according to the determination threshold and the peak value point is calculated; the Doppler signal is corrected according to the peak value point, the position average value of the zero point is calculated, and the positions of the rising section zero point, the falling section zero point, the positive peak value point and the negative peak value point are obtained; the instantaneous frequency of the laser Doppler signal and the corresponding time are calculated according to the positions of the four kinds of points, the laser Doppler signal demodulation speed signal is calculated according to the parameters of the laser speed tester and the cooperative grating, the efficient and accurate demodulation processing of the laser Doppler impact test signal is realized, and the measurement precision of the impact test is improved.

Method of generating a biphasic triangular pulse using a device having a voltage bank with an adjustable voltage level; use of such pulse to induce a current flow in an individual's brain. A voltage control device of the device includes one or more switches (e.g., IGBTs) and / or one or more inductors. Energy from the voltage bank is discharged into a magnetic coil of the device, with the voltage bank at a first voltage level. When the energy in the coil reaches a predetermined positive peak, the polarity of the voltage is reversed (i.e., the voltage level is set to a second voltage, which may be a negative equivalent of the first voltage level). When the voltage reaches a negative peak, the voltage level is returned to the first (positive) voltage level. The changing polarity results in a biphasic pulse, which may be unidirectional or bidirectional.

The invention discloses a freeze-drying stage conversion judgment method and system based on weightlessness acceleration peak detection, and belongs to the technical field of freeze-drying process control. According to the method, the average weight loss rate of freeze-dried materials is calculated by monitoring weight loss data of the freeze-dried materials in real time, and the weight loss acceleration is further solved; and by tracking the signal of the weightlessness acceleration in real time, identifying the unique and obvious negative peak value appearing in the whole freeze-drying process, and judging the peak value point as an inflection point of conversion from the sublimation drying stage to the desorption drying stage. According to the method, a fixed judgment threshold value related to the materials does not need to be preset, full-automatic, self-adaptive and high-precision stage conversion judgment is achieved, the universality and the intelligent level of the method are remarkably improved, and meanwhile the system cost and the debugging complexity are reduced.

The application discloses a third harmonic injection method and device suitable for converter circulating current control, and the method comprises the following steps: obtaining the amplitude and phase of a converter power frequency modulation wave and the amplitude and phase angle of a second harmonic modulation voltage introduced by the converter circulating current control; determining the amplitude and phase of the third harmonic injection voltage when the maximum and minimum of the positive and negative peak values of the converter alternating current modulation wave are determined according to the relationship between the amplitude and phase angle of the second harmonic modulation voltage introduced by the converter circulating current control and the amplitude and phase of the converter power frequency modulation wave. The application can improve the consistency of the positive and negative peak values of the converter modulation wave, thereby further improving the rated voltage of the valve side of the converter transformer, reducing the converter valve and related current, and reducing the system loss.

The invention discloses a control method and a control circuit of a switching power supply and the switching power supply, the switching power supply comprises a first switching tube and a second switching tube, the first switching tube is used as a main switching tube of the switching power supply, the second switching tube and the first switching tube are alternately conducted, and the second switching tube is used as a main switching tube of the switching power supply. Controlling the turn-off of the first switching tube according to the first jitter signal so as to enable an inductive current peak value to jitter along with time; the second switching tube is controlled to be turned off according to a second jitter signal, so that an inductive current negative peak value jitters along with time at least in a part of time period, when the inductive current negative peak value jitters along with time, the jitter direction of the inductive current negative peak value is opposite to the jitter direction of the inductive current peak value, and the jitter direction of the inductive current negative peak value is opposite to the jitter direction of the inductive current peak value. Therefore, the output power fluctuation is reduced. The EMI characteristics can be optimized, and output voltage ripples can be reduced.