24 results about "Unipolar pulse" patented technology

The invention relates to the technical field of meteorological observation, in particular to a parameter measurement method and device based on a dual-band mode, equipment and a storage medium. Generating a dual-band excitation signal according to the aligned sine wave signal; analyzing the echo signal according to a preset gain coefficient, a time difference method and a preset attitude compensation formula to obtain a reconstructed quasi-unipolar pulse, an actual wind speed, a horizontal wind direction angle, a pitch angle, a three-dimensional wind speed vector, a roll angle and a real wind direction; acquiring real-time air pressure, and correcting a preset standard state sound velocity according to a preset sound velocity correction formula and the real-time air pressure to obtain a corrected sound velocity; according to the scheme, a dual-band signal attached to a medium is generated, after efficient transmission analysis, high-resolution pulses and multi-dimensional wind field parameters are obtained by means of gain, a time difference method, attitude compensation and the like, the sound velocity is corrected in combination with air pressure, comprehensive, accurate and rapid updating of data are considered, and the measurement reliability is improved.

Systems and methods for unipolar Pulse-Field Ablation (PFA) are disclosed for reducing spasm and / or other adverse nerves stimulation effects during delivery of PFA pulses. The system includes or is connected to one or more motion sensors to be placed at one or more regions of a patient's body for monitoring spasm thereat. The system includes a signal switch capable of selectively connecting a PFA energy generator to selected one or more of return electrode patches for delivery of PFA pulses and / or pacing signals through the selected electrode patches; and a processor that monitors motion sensed by the motion sensor(s) during delivery of the PFA pulses or pacing signals to identify nerve stimulation effects, such as spasm, to facilitate, based on the monitoring, selection of certain electrode patches by which the PFA pulses may be delivered without, or with reduced spasm or other adverse effects of excessive nerves stimulation.

The present invention discloses a high-bandwidth single-phase full-bridge inverter control method, system and inverter based on inverse model control, the method comprising: collecting the output voltage and output inductor current on the load; using a single-phase phase-locked loop structure to generate a phase triangle wave consistent with the output voltage phase; using the output signal of the reference current command through the inverse model controller as the first control signal; using a current loop P controller superimposed with a second-order low-pass filter as a current loop total gain controller to adjust the reference current command and the first error signal of the output current, and using a unipolar modulation method to modulate the total control signal to generate a PWM pulse for controlling the output voltage of the single-phase inverter. The present invention constructs a single-phase inverter control strategy based on the inverse model idea combined with a P controller and a unipolar pulse modulation method, thereby realizing zero-static-error tracking under a high-bandwidth inverse model control mode, and can realize zero-static-error tracking of broadband input signals, with the characteristics of easy implementation and high following accuracy.

The invention discloses a method for improving corrosion resistance of a pure aluminum surface in a NaCl solution, and relates to the technical field of high-current pulsed ion beams, an experiment is carried out on a TEMP-6 type HIPIB device, and a polymer anode unipolar pulse mode external magnetic insulation ion diode is adopted to generate 70% C and 30% H ion beams for an irradiation experiment; the ion beam parameters are as follows: the acceleration voltage is 300kV, the pulse width is 70-80ns, the beam density is 100A / cm < 2 >, the irradiation frequency is five times, and the background vacuum degree of a vacuum chamber during irradiation is 10 <-3 > Pa.

Systems and methods for unipolar Pulse-Field Ablation (PFA) are disclosed for reducing spasm and / or other adverse nerves stimulation effects during delivery of PFA pulses. The system includes or is connected to one or more motion sensors to be placed at one or more regions of a patient's body for monitoring spasm thereat. The system includes a signal switch capable of selectively connecting a PFA energy generator to selected one or more of return electrode patches for delivery of PFA pulses and / or pacing signals through the selected electrode patches; and a processor that monitors motion sensed by the motion sensor(s) during delivery of the PFA pulses or pacing signals to identify nerve stimulation effects, such as spasm, to facilitate, based on the monitoring, selection of certain electrode patches by which the PFA pulses may be delivered without, or with reduced spasm or other adverse effects of excessive nerves stimulation.

The present application belongs to the field of particle radiation measurement technology and related electronics, and particularly relates to a pulse direct sampling system and method for particle radiation measurement. The system comprises a charge conversion module, a signal conditioning output module and an AD acquisition module. The charge conversion module acquires the particle radiation charge signal output from the front end, converts it into a unipolar pulse signal and outputs it to the signal conditioning output module. The signal conditioning output module comprises a slow shaping submodule and a fast shaping submodule. The slow shaping submodule filters, shapes and amplifies the unipolar pulse signal and outputs it to the AD acquisition module. The fast shaping submodule filters, shapes and amplifies the unipolar pulse signal and outputs it as a trigger signal to the AD acquisition module. After receiving the trigger signal, the AD acquisition module directly samples the signal output by the slow shaping submodule according to the time difference between the signals output by the slow shaping submodule and the fast shaping submodule after waiting for a corresponding time.

Aspects of this disclosure relate to driving a capacitive micromachined ultrasonic transducer (CMUT) with a pulse train of unipolar pulses. The CMUT may be electrically excited with a pulse train of unipolar pulses such that the CMUT operates in a continuous wave mode. In some embodiments, the CMUT may have a contoured electrode.

Systems and methods for unipolar pulsed field ablation (PFA) are disclosed for reducing spasticity and / or other adverse neurostimulation effects during delivery of PFA pulses. The system includes or is connected to one or more motion sensors to be placed at one or more regions of a patient's body for monitoring spasticity at that region. The system includes a signal switch capable of selectively connecting the PFA energy generator to a selected one or more of the return electrode patches for delivering PFA pulses and / or pacing signals through the selected electrode patch; and a processor that monitors motion sensed by the motion sensor during delivery of the PFA pulse or pacing signal to identify a neurostimulation effect, such as spasm, to facilitate selection of a particular electrode patch by which the PFA pulse may be delivered based on the monitoring, and no or reduced spasm or other adverse effects of excessive nerve stimulation can be generated.

The application discloses a variable frequency motor rotating speed and direction measuring system and a measuring method. The measuring system comprises a driving power supply, a first sampling branch and a second sampling branch, the input ends of the first sampling branch and the second sampling branch are connected with a first phase power line and a second phase power line respectively, the first sampling branch and the second sampling branch comprise a current-voltage conversion unit, an amplification filtering unit and a square wave rectification unit connected in sequence respectively, the square wave rectification unit rectifies and outputs a unipolar pulse wave signal, a single-chip microcomputer collects a first pulse wave signal output by the first sampling branch and a second pulse wave signal output by the second sampling branch in a digital filtering mode by using an ADC mode, and obtains a first digital sequence and a second digital sequence, and the single-chip microcomputer obtains the rotating speed and direction of the variable frequency motor according to the first digital sequence and the second digital sequence. The application can directly use the electric signal of the driving power supply to measure the rotating speed and direction of the motor, and the environment is simple to construct and has good consistency.

The invention relates to the technical field of food preservation, in particular to a fresh food processing method based on electrostatic preservation, which comprises the following steps: detecting the stacking height of fresh food through a pressure sensor array, and driving a telescopic auxiliary electrode on the side wall of a preservation bin to extend by an adaptive length to be matched with the shape of a stack body; positive and negative alternate bipolar pulse electric fields are applied to the top net-shaped main electrode and the telescopic auxiliary electrode, so that rapid sterilization and uniform charge distribution are realized; and after the preset high-frequency processing, a unipolar pulse electric field is switched, and the pulse frequency is dynamically adjusted based on the fresh food conductivity detected in real time so as to adapt to the electromagnetic property difference of different fresh foods. According to the method, through dynamic optimization of electrode space layout and coordinated regulation and control of pulse parameters, the microbial activity and the cell metabolism rate are effectively inhibited, meanwhile, the electric field distribution uniformity is ensured, the problems of response lag, high energy consumption and poor adaptability in the traditional technology are solved, the fresh keeping period is remarkably prolonged, and the treatment energy consumption is reduced.

The invention discloses a pulse generation method for pulse ablation, which relates to the technical field of medical equipment, and comprises the following steps: when a unipolar pulse is generated, closing MOS (Metal Oxide Semiconductor) tubes Q1, Q3 and Q4, conducting an MOS tube Q2, and pre-charging a bootstrap capacitor C1 through a driving chip P1; after pre-charging is completed, triggering signals are input to corresponding pins of the driving chips P1 and P2, and unipolar pulses are generated at the two ends of the load RL; when a bipolar pulse is generated, the MOS tubes Q1 and Q3 are closed, the MOS tubes Q2 and Q4 are conducted, and the bootstrap capacitors C1 and C2 are pre-charged through the driving chips P1 and P2 respectively; after pre-charging is completed, trigger signals are input to corresponding pins of the driving chips P1 and P2, and positive polarity pulses are generated at the two ends of the load RL. According to the invention, a bootstrap gate drive circuit and a pre-charging management strategy are combined, and miniaturized, low-power-consumption and high-precision unipolar / bipolar pulse output is realized.

The invention discloses an antenna switch based on a radio frequency transmission line and an avalanche diode and a control method of the antenna switch. An antenna comprises a signal source, the avalanche diode, a receiver and the radio frequency transmission line. The control method comprises the following steps: transmitting a unipolar pulse signal through a signal source to perform reverse breakdown conduction on a first avalanche diode, a second avalanche diode and a third avalanche diode, and transmitting the signal to an output end and a second radio frequency transmission line through a first radio frequency transmission line; the second radio frequency transmission line reflects the unipolar pulse signal, delays a preset time and transmits the unipolar pulse signal to the output end of the first radio frequency transmission line, and the output end forms a bipolar pulse waveform which is radiated outwards through the antenna. According to the invention, automatic switching of the antenna switch between transmitting and receiving can be realized without a peripheral control circuit. The antenna switch based on the radio frequency transmission line and the avalanche diode and the control method thereof can be widely applied to the technical field of transceiving antenna switch control.

The invention discloses a subnanosecond pulse source device with continuously adjustable width, and the device comprises a driving module which is used for carrying out the continuous time delay adjustment of one path of sine excitation signal distributed by a power divider through changing the voltage of a voltage-controlled phase shifter, and carrying out the continuous time delay adjustment of the other path of sine excitation signal distributed by the power divider through combining with the other path of sine excitation signal distributed by the power divider. A double-channel square wave signal with continuous and adjustable relative time delay is generated to drive a Gaussian pulse generator module; the Gaussian pulse generator module is used for generating two paths of subnanosecond negative pulse signals under the triggering of the two-channel square wave signals with continuously adjustable relative time delay, and the time interval continuously changes along with the time delay adjustment of the voltage-controlled phase shifter; the pulse synthesis and polarity selection module is used for performing polarity conversion on one sub-nanosecond negative pulse signal to obtain a positive pulse signal; performing power synthesis on the positive pulse signal and the other sub-nanosecond negative pulse signal to obtain a bipolar pulse; and a subnanosecond-level unipolar pulse signal with continuously adjustable width is obtained through detection.

The application relates to a method for operating an inverter that has an H4 bridge circuit having a first half-bridge and a second half-bridge for converting an input-side direct voltage into an output-side alternating voltage and is configured for supplying electrical power of a direct voltage source with a variable potential relative to a ground potential, for example, of a photovoltaic generator with a leakage capacitance with respect to ground, to an alternating voltage grid. The method includes unipolar pulse-width-modulated clocking for each of the two half-bridges for the half-wave generation of substantially sinusoidal half-bridge voltages, and modifying the clocking of the half-bridges in a transition region around a zero crossing of the output-side alternating voltage to damp a leakage current (IA) that flows through the leakage capacitor to ground. The application also relates to an inverter and to a computer program product.

The invention relates to the technical field of electric power engineering, discloses a cable fault identification method based on bipolar pulse square wave excitation, and solves the problems that in the prior art, when a cable fault point is identified, sine waves are used for excitation, the frequency is single, and detail changes are difficult to capture. The bipolar pulse square wave is used as the excitation signal, compared with sine wave and square wave signals, the bipolar pulse square wave has rich harmonic component characteristics, the high-frequency impedance characteristic of the shielding cable in the broadband range can be effectively obtained, and compared with unipolar pulse square waves, the bipolar pulse square wave has the advantage of being wider in harmonic distribution range. After the excitation signal is injected into the shielded cable, the response signal of the shielded cable is collected to obtain the real impedance spectrum, and the real impedance spectrum and the standard impedance spectrum generated based on the transmission line model are compared and analyzed to identify and position the fault point, so that the cable fault point can be identified in a wider frequency range; and detail change capture of the cable under excitation is realized.

The embodiment of the invention discloses a single-phase inverter active filtering method and device based on current slope control, and the method comprises the steps: firstly, converting the voltage of a DC power supply through an L-type grid-connected single-phase bridge type inverter through a single-pole pulse width modulation technology, and generating a pulse width modulation wave output voltage; in the process of generating the pulse width modulation wave, a current slope change rule is generated by performing relation analysis on slope change factors influencing the output current. Afterwards, according to a current slope change rule, an active filtering single-phase inverter is utilized to compensate the voltage change at the two ends of the inductor, and control over the current slope in the direct current conversion process is guaranteed. According to the embodiment of the invention, the design of the filter inductor is optimized at the cost of increasing an additional bridge circuit, and the filter inductance value is reduced by 5-10 times. After the size of the filter is greatly reduced, it can be guaranteed that the harmonic suppression effect is not affected.

This disclosure presents an active filtering method and apparatus for a single-phase inverter based on current slope control. The method includes: first, using unipolar pulse width modulation (PWM) technology, converting the DC power supply voltage through an L-type grid-connected single-phase bridge inverter to generate a PWM output voltage. During PWM generation, the relationship between factors affecting the slope change of the output current is analyzed to generate a current slope change law. Then, based on the current slope change law, an active filtering single-phase inverter is used to compensate for voltage changes across the inductor, ensuring control of the current slope during DC-DC conversion. This disclosure optimizes the filter inductor design at the cost of adding an additional bridge circuit, reducing the filter inductance value by 5 to 10 times. This achieves a significant reduction in filter size while maintaining unaffected harmonic suppression.

The pulse power supply device (100) includes pulse power supplies (P1 to Pn) that respectively output unipolar pulse voltages and transformers (Tr1 to Trn). The transformers (Tr1 to Trn) each have a primary winding (La1 to Lan), a secondary winding (T1 to Tn), and a tertiary winding (T1s to Tns). One pulse power supply is connected to one primary winding one by one. The secondary windings (T1 to Tn) are connected in series in sequence, and a load (8) is connected to both ends of the secondary windings (T1 to Tn). The tertiary windings (T1s to Tns) are connected in series in sequence, and a magnetic reset circuit (4) is connected to both ends of the tertiary windings (T1s to Tns). The magnetic reset circuit (4) includes a magnetic reset power supply (E1) and an impedance change circuit (U1) for restricting the induced current that can flow due to the voltage induced in the tertiary windings (T1s to Tns). The impedance change circuit (U1) is configured to be able to change the impedance.

The application discloses an active resonant magnetic reset method of a unipolar pulse transformer, and belongs to the technical field of pulse power. The unipolar pulse transformer is used for driving each minimum working unit of a unipolar pulse power supply. The method comprises the following steps: measuring equivalent leakage inductance, equivalent excitation inductance and equivalent turn ratio of the unipolar pulse transformer; establishing an approximate magnetic hysteresis loop of a magnetic core of the unipolar pulse transformer and evaluating coercive force; installing controllable RC damping circuits in parallel at each primary side port of the unipolar pulse transformer and connecting power diodes in series on secondary side windings; calculating optimal conduction time of a reset MOSFET switch; and controlling the conduction time of the reset MOSFET switch rapidly after a main MOSFET switch is turned off, so that magnetic reset of the unipolar pulse transformer is realized. The method solves the problems of safety hazards, energy efficiency loss and system complexity of a traditional scheme by introducing a small amount of low-cost additional circuits and a cooperative control strategy.

To provide systems and methods for unipolar Pulse-Field Ablation (PFA).SOLUTION: Systems and methods for unipolar Pulse-Field Ablation (PFA) are disclosed for reducing spasm and / or other adverse effects of nerve stimulation during delivery of PFA pulses. The system includes or is connected to one or more motion sensors to be placed at one or more regions of a patient's body for monitoring spasm thereat. The system includes a signal switch capable of selectively connecting a PFA energy generator to selected one or more of return electrode patches for delivery of PFA pulses and / or pacing signals through the selected electrode patches; and a processor that monitors motion sensed by the motion sensors during delivery of the PFA pulses or pacing signals to identify nerve stimulation effects, such as spasm, to facilitate, based on the monitoring, selection of certain electrode patches by which the PFA pulses may be delivered with no or reduced spasm or other adverse effects of excessive nerve stimulation.SELECTED DRAWING: Figure 1

The invention discloses an ultrahigh-frequency ultrasonic transducer capable of generating quasi-unipolar pulses, and belongs to the technical field of ultrasonic transducers. The transducer comprises a backing layer, a high-frequency piezoelectric layer and a combined layer which are sequentially arranged from bottom to top. The combined layer comprises an acoustic decoupling layer, a first high-frequency matching layer, a second high-frequency matching layer, an ultrahigh-frequency piezoelectric layer, an ultrahigh-frequency polymer matching layer and an ultrahigh-frequency metal matching layer. A penetrating cavity is arranged between the first high-frequency matching layer and the second high-frequency matching layer, and an acoustic decoupling layer, an ultrahigh-frequency piezoelectric layer, an ultrahigh-frequency polymer matching layer and an ultrahigh-frequency metal matching layer are sequentially arranged in the penetrating cavity in a stacked mode. During working, the high-frequency piezoelectric layer and the ultrahigh-frequency piezoelectric layer can be driven to generate forward waves of high-frequency ultrasonic waves and ultrahigh-frequency ultrasonic waves respectively by reasonably adjusting electric excitation parameters, and the forward waves of the high-frequency ultrasonic waves and the ultrahigh-frequency ultrasonic waves are superposed, so that quasi-unipolar pulses with sharp main lobes and low side lobe levels are synthesized. The problem of pulse trailing of the ultrahigh frequency transducer is effectively solved, the axial resolution is remarkably improved, and meanwhile high detection sensitivity is kept.

The invention discloses a frequency / waveform adjustable bipolar Gaussian pulse source and a working method thereof, and belongs to the field of electronic circuits. According to the pulse source, a bipolar pulse is obtained in a mode that a positive unipolar pulse and a negative unipolar pulse are subjected to delay synthesis. The main structure is divided into the following parts: a positive unipolar pulse circuit, a negative unipolar pulse circuit, a delay trigger circuit, a direct current input circuit, an isolation circuit and a filter shaping circuit. The unipolar pulse source adopts a multi-stage Marx circuit, a triode is used as a switch, and energy storage capacitors are connected in parallel for charging when the unipolar pulse source is closed; during triggering, the triodes are subjected to avalanche breakdown, the energy storage capacitors are connected in series for discharging, and the output amplitude is multiplied. Specific delay trigger signals are generated through the delay circuit to control the two unipolar sources to output in sequence, output pulses of the two unipolar sources are integrated through the isolation circuit, and final output is obtained through processing of the filter circuit. The frequency spectrum and the waveform of the output pulse can be flexibly adjusted by adjusting the capacitance, the circuit series and the filter circuit element parameters in the Marx circuit.

Method of accelerated extinguishing of residual current of a phase that opens when changing an electric position during the driving of a BLDC motor (10), under high load conditions, comprising:using the unipolar pulse width modulation pattern ON_PWM to drive the BLDC motor (10);determining if there is residual current by means of monitoring the voltage of the phases that opens using a voltage observer (40);while there is residual current, applying a switching pattern, on the switches (S1-S6) of the BLDC motor (10), which superimposes the pulse width modulation pattern used and maximizes the voltage in the open phase for the accelerated extinguishing of said residual current,said switching pattern comprising:opening the switch of the phase maintained driven when changing the electrical position; andclosing the switch related to the phase that was driven when changing the electric position.

Aspects of this disclosure relate to driving a capacitive micromachined ultrasonic transducer (CMUT) with a pulse train of unipolar pulses. The CMUT may be electrically excited with a pulse train of unipolar pulses such that the CMUT operates in a continuous wave mode. In some embodiments, the CMUT may have a contoured electrode.