30 results about "Self excited oscillation" patented technology

The application provides a salt-preventing ocean high-pressure water pump port ring structure based on coupled oscillation, and belongs to the technical field of ocean water pump equipment, and comprises a pump body port ring and an impeller port ring, and an annular gap is formed between the two; a nozzle-shaped first groove is arranged on the inner circumferential surface of the pump body port ring, and a second groove with an inclined wall surface and a backflow channel is arranged on the outer circumferential surface of the impeller port ring; the first groove and the second groove are connected to form a fluid oscillation channel. Through the matching design of the circumferential interval of the groove and the rotating speed of the impeller, the groove connection-separation frequency reaches the ultrasonic frequency band, and double coupling of fluid self-excitation oscillation and ultrasonic vibration is realized. The application effectively prevents salt deposition under the premise of not changing the existing lubrication mode, and significantly improves the water film lubrication performance and the service life of the equipment.

This invention relates to a ball-operated plugging device for downhole pulsating hydraulic fracturing, comprising a main body assembly. A conical valve seat is disposed in the middle of the main body assembly, and an umbrella-shaped valve is slidably connected within the conical valve seat. The umbrella-shaped valve includes a valve head boss and a valve stem. A self-excited oscillation chamber is also provided at the bottom of the conical valve seat. A spring support seat is disposed below the self-excited oscillation chamber, with a central circular hole at the geometric center of the spring support seat. A spring is placed on the spring support seat, and the top of the spring contacts the valve head boss of the umbrella-shaped valve. A through-hole flow channel is provided in the middle of the umbrella-shaped valve, with its upper and lower ends communicating with cavity A and cavity B, respectively. The valve stem of the umbrella-shaped valve passes through the spring, and its bottom is inserted into the central circular hole of the spring support seat. A spherical groove is provided at the top of the umbrella-shaped valve for placing a soluble plugging ball. This invention can adjust the pressure variation of the pulsating fluid at the bottom of the well during construction.

This invention relates to the field of flow battery technology and discloses a method and system for regulating self-excited oscillation in flow batteries. By integrating a flow oscillation generator into the electrolyte circulation loop of the flow battery, the periodic vortex ring oscillation and acoustic-fluid positive feedback phenomenon generated by the flow within the resonant cavity of this device are utilized to achieve pulsating regulation of electrolyte flow rate and pressure. This fundamentally improves the convective mass transfer efficiency at the electrode / electrolyte / diaphragm interface within the flow battery stack, thereby alleviating concentration polarization at the battery reaction interface caused by factors such as uneven flow rate, thickened diffusion boundary layer, and restricted ion migration. Furthermore, this device eliminates the need for long-term, additional electrical drive and complex control components, exhibiting a simple structure and stable operation.

The utility model relates to a kind of load impedance measurement circuit, system and equipment, including waveform control circuit, load impedance acquisition circuit, signal amplification circuit, analog signal conversion PWM circuit, filter circuit and MCU connected in turn;Waveform control circuit includes self-oscillation circuit and rectangular wave output circuit, rectangular wave output circuit receives the rectangular wave that self-oscillation circuit exports and reference voltage comparison generates complementary rectangular wave output to load impedance acquisition circuit, load impedance acquisition circuit gathers load impedance and exports direct current signal to signal amplification circuit, analog signal conversion PWM circuit gathers amplified signal conversion as digital signal to filter circuit and carries out filter processing, and MCU receives the signal after filter processing of filter circuit.The utility model uses self-oscillation and complementary rectangular wave output circuit to form sampling circuit combination, the signal gathered is more accurate, and it is easy to be read and further processed by lower circuit, and finally the impedance measurement value of equipment is more accurate.

A self-excitation microwave sensor suitable for non-destructive testing of metal mesh film, belonging to microwave sensor technology, comprising a resonant sensing structure, a microwave amplifier, a phase shift element, a band-pass filter, a radio frequency detector, a digital-to-analog converter and a microprocessor; wherein the resonant sensing structure, the microwave amplifier, the phase shift element and the band-pass filter form a self-excitation oscillation loop, the resonant sensing structure has a band-pass characteristic, is located in the feedback branch of the loop, the resonant frequency thereof is consistent with the center frequency of the band-pass filter, and the loop gain and the phase shift satisfy the self-excitation oscillation condition at the frequency; by reasonably setting the gain of the microwave amplifier and collecting the self-excitation oscillation signal power in real time, the sensor can realize detection of sub-millimeter width crack damage and identification of high square resistance samples, has high detection sensitivity, compact structure, small volume and low cost, does not need other external microwave analysis instruments, and can be applied to on-site non-destructive testing of metal mesh film.

This invention discloses a casting apparatus and casting process for lead-free brass water meter housings, relating to the field of brass casting technology. It includes a main body, a fixing unit, a pretreatment unit, a pneumatic unit, and a control unit. The fixing unit clamps the water meter housing; the control unit monitors the casting temperature in real time via a temperature sensor. When the water meter housing is in the hot brittle range above 300°C, the air supply unit only outputs airflow for gentle cooling to prevent deformation and cracking of the casting. When the temperature drops to 200°C from 300°C, the air supply unit outputs high-pressure airflow to drive a vibrating unit, using high-frequency self-excited oscillation to break down and peel off the internal molding sand. When the temperature drops below 200°C, the air supply unit outputs pulsed airflow to drive a striking unit, reciprocatingly striking the outer wall of the water meter housing to remove residual molding sand. Finally, the extraction unit uses negative pressure to extract and separate the molding sand. This invention solves the problem of easy damage or difficult sand removal of lead-free brass water meter housings at different cooling stages, achieving efficient and non-destructive sand removal.

This invention relates to a self-oscillating closed-loop voltage regulator circuit, comprising a self-oscillating circuit, a primary power supply undervoltage indicator circuit, a secondary power supply undervoltage indicator circuit, a key valid indicator circuit, a power amplifier circuit, and a boost control circuit. The self-oscillating circuit outputs a fixed-frequency reference square wave signal. Undervoltage, overvoltage, and key valid indicator signals are passed through an AND gate to output a variable-frequency square wave signal. This variable-frequency square wave signal is then passed through a complementary pull-up circuit to increase the driving capability. The complementary output variable-frequency square wave controls the boost circuit. When the battery is low or the secondary power supply is undervoltage, the output frequency of the self-oscillating circuit controls the switching of the boost circuit to achieve rapid voltage boost. When the battery and secondary power supply voltages are normal, the boost control circuit is shut down. This effectively ensures stable operation under normal control conditions and is particularly suitable for the automotive electronics industry.

This invention belongs to the technical field of engineering vibration control and discloses a real-time suppression method for low-frequency oscillations based on a fully closed-loop servo drive system. The invention utilizes dual encoder feedback on the motor and load sides to extract the position deviation signal, which is then input to a PD compensator with a first-order low-pass filter. The output of this compensator is superimposed on the torque command side to suppress low-frequency self-excited oscillations caused by nonlinear factors. Based on this, the fully closed-loop system is equivalent to a second-order model, and its natural frequencies are identified. ω Based on the damping ratio and the tolerable oscillation level, the input shaper pulse sequence is designed to convolve and shape the original position command, suppressing low-frequency residual oscillations. Simultaneously, the differential and second-order differential signals of the command are shaped and used in conjunction with the feedforward gain to generate the speed and acceleration feedforward amount, compensating for the time delay introduced by the shaper. This invention achieves real-time suppression of low-frequency oscillations under all operating conditions through the synergistic effect of feedforward shaping and feedback compensation, making it easy to deploy and apply in industrial servo drives.

This invention discloses an adaptive constant temperature control method and system for circulating water pumps based on ambient temperature, relating to the field of adaptive constant temperature control. The method involves acquiring the spatial structural parameters of an air conditioning cooler, constructing a three-dimensional thermal and humid air motion model coupling exhaust and intake airflows, generating a potential energy field for the risk of exhaust hot and humid air mass recirculation based on the three-dimensional thermal and humid air motion model, and combining real-time ambient temperature, forecast temperature, and meteorological boundary conditions to perform recirculation self-excited oscillation detection. A corrected equivalent ambient temperature is output to eliminate recirculation self-interference deviation. Using the corrected equivalent ambient temperature as a feedforward variable, a target operating current setpoint for the water pump is generated through a compensation function that compensates for the inverse relationship between the pump operating current and ambient temperature. After smoothing and filtering, the setpoint is output to the variable frequency drive of the circulating water pump. The variable frequency drive adjusts the output frequency according to the current setpoint to ensure that the pump operating current tracks the setpoint, maintaining a constant cooling water supply temperature.

This invention provides a method for dynamically adjusting the current distribution of feeders in a distribution cabinet, relating to the field of distribution cabinet technology. By real-time acquisition and fusion of contact temperature, feeder current, and cabinet humidity data, the method identifies target feeders with current deviations and detects the starting moment when the current distribution changes from unidirectional deviation to reciprocating alternating oscillations. Combining fluctuation amplitude clustering and critical humidity cross-comparison, the method determines the feeder group that needs immediate adjustment and simultaneously executes bus tie switch switching, adjustable shunt branch capacity configuration, and heating and dehumidification module activation. This solves the problem of unpredictable and uncontrollable self-excited oscillating current fluctuations caused by dynamic changes in contact resistance due to contact oxidation, effectively suppressing repeated current transfers between feeders and improving the stability of current distribution and power supply safety and reliability in the distribution cabinet.

The present application relates to cold air cooling technology field, disclose a kind of flexible micropore cold air cooling system and its heat dissipation structure, including cold source access end, flexible air duct body, low-frequency large flow electromagnetic air valve and sensing and control unit.Cold source access end introduces cold air, low-frequency large flow electromagnetic air valve is connected with the flexible air duct body of cold source access end.Sensing and control unit collects air temperature, relative humidity and target object surface temperature data, calculates dewing prevention safety boundary temperature, generates low-frequency pulse width modulation signal control air valve opening and closing.Cold air enters flexible air duct body when air valve is opened, and the self-excited oscillation pressure-sensitive micropore distributed on surface is subjected to high-frequency deformation under the action of alternating air pressure.The present application utilizes aerodynamic vortex to destroy the thermal boundary layer attached to the surface of target object to improve heat exchange efficiency, and dynamically adjusts cold input according to temperature change, maintains the dynamic balance of cooling and dewing prevention state, to avoid condensation.

This invention relates to a core microwave amplifier chip application verification system and method for aerospace applications, belonging to the field of electronic technology. The application verification method and system of this invention combine the inherent characteristics of the device with the requirements of aerospace applications, constructing a complete set of methods and systems for microwave amplifier application verification, which can meet the needs of microwave amplifier aerospace application verification. This invention develops targeted tests for the inherent characteristics, process features, and common failure modes of microwave amplifiers. For example, it designs stability evaluation for amplifier self-excited oscillation, hydrogen resistance evaluation for hydrogen effects, anti-mismatch capability evaluation for power reflection caused by output mismatch, and lifetime assessment for the impact of various operating conditions on lifetime, ensuring the efficiency and relevance of the verification.

This invention relates to a motor with a liquid-cooled housing. The inner wall of the cooling channel within the motor housing is equipped with a self-excited oscillation unit for actively disturbing and disrupting the high thermal resistance inner boundary layer. The self-excited oscillation unit consists of a contraction nozzle, an expansion interaction chamber, a feedback loop, and a sweeping outlet. During operation, the contraction nozzle converts the coolant into a high-speed central jet that enters the expansion interaction chamber. Utilizing the wall adhesion effect, the jet tends to flow along one side wall, forming a high-pressure zone downstream of the chamber. This high-pressure fluid is transmitted to the nozzle outlet flank via the lateral feedback loop, disrupting the original wall adhesion balance through a lateral pressure pulse, forcing the jet to flip to the other side, thereby generating continuous self-excited oscillation. Finally, the fluid is ejected through the fan-shaped sweeping outlet, physically sweeping the channel wall with a high-frequency oscillating dynamic stream, greatly improving the motor's heat exchange efficiency and temperature field uniformity.

The application discloses a small frequency difference MEMS gyroscope detection phase shift suppression system, which is composed of a MEMS gyroscope, a driving loop, an angular velocity demodulation module and a parametric suppression loop. The application focuses on applying a parametric suppression signal to the detection resonator, electrostatically correcting the amplitude-phase frequency response, suppressing the detection phase shift under the small frequency difference mode, and improving the impact resistance. The detection resonator is embedded in the parametric suppression loop to generate stable amplitude self-excitation oscillation. A band-pass phase shifter is used to generate a parametric suppression signal twice the detection frequency from the detection amplitude multiplier. After the phase is shifted by 90 degrees to meet the parametric suppression phase condition, the parametric suppression signal acts on the parametric suppression electrode. Without losing the mechanical sensitivity of the MEMS gyroscope, the detection phase shift and the resonance peak amplitude at the detection natural frequency are suppressed, and the impact resistance is improved.

The utility model belongs to pipeline cleaning technical field especially, it relates to a kind of self-excitation oscillation nozzle for pipeline cleaning, including high-pressure pipeline and the cleaning device connected with it, mechanical rotating handle is equipped on winch, the cleaning device includes the jet nozzle of being located in the center and the booster pump export pipeline connection, still include the central righting mechanism of fixed jet nozzle, the device is by using self transport medium, the jet technology of combining self-vibration pulse and cavitation effect is used to solve the technical bottleneck of not being cleaned thoroughly in the use of existing nozzle.

The present application relates to a kind of oxygen-removing device low-temperature reheat steam source pressure regulating system, including entity equipment and control hub in the technical field of thermal power plant cogeneration and boiler bypass heat supply stable pressure regulation and control, entity equipment includes feedforward perception matrix, acoustic muffling flash device, residual waveform sensing node, pneumatic damping valve array and porous jet pipe network.System acquires parameters through feedforward perception matrix, utilizes evolution prediction module to output the space coordinates and pressure wave frequency band of unvaporized water droplet induced flash expansion.Stable pressure intervention module adjusts the physical volume of acoustic muffling flash device according to prediction result and activates microwave phase change excitation field, eliminates pressure pulsation and promotes water droplet instantaneous phase change.At the same time, calculate the antiphase compensation waveform to drive pneumatic damping valve array to implement fluid interference cancellation, smooth steam passes through porous jet pipe network self-excitation oscillation jet injection, eliminate vacuum negative pressure area, prevent oxygen-removing device internal transient water hammer.

The application discloses a self-oscillation comparator and method for successive approximation analog-to-digital converter, and belongs to the field of analog and mixed signal integrated circuit design. The application comprises a differential input stage, a self-oscillation core, an isolation and clock control unit, an oscillation detection module, a counting decision module and an output interface module. The application converts the input differential voltage into the difference of the number of times of flipping of two oscillation nodes within a fixed time window, and counts the difference by the oscillation detection module and the counting decision module to output the comparison result. The application realizes the orderly switching of the sampling, isolation, comparison and reset stages by the multiphase clock control, effectively reduces the random noise and input kickback interference, improves the decision robustness of the comparator under the condition of low power voltage and small input difference, and can be widely applied in low-power medium-speed SAR ADC, sensor interface and mixed signal system chip.

This invention provides a hydraulically driven self-excited oscillating nozzle. As a novel device that optimizes water spraying performance by relying on the self-excited oscillation effect of fluid, this nozzle aims to solve the problems of limited spray range and uneven coverage caused by high jet concentration in traditional nozzles. Its core structure integrates a self-excited vibration resonant cavity and an oscillating flow channel. During operation, the pressure pulsation formed by water flowing through the special flow channel couples with the resonant cavity, causing the ejected jet to undergo radial diffusion and pulsation breakup under the action of self-excited oscillation, significantly enhancing the jet's spreading ability. Compared to traditional nozzles, this type of nozzle not only retains the advantages of small atomized particle size, low energy consumption, compact structure, and no need for an external power supply, but also achieves a significant expansion of the spraying range. It provides key equipment support for efficient, water-saving, large-area water spraying technology and has significant practical implications for improving water spraying efficiency and reducing water consumption.

This application discloses an indoor air conditioning unit and an air conditioner. The indoor air conditioning unit has a movable damper on its casing, which is used to open or close a first air outlet of the casing. When the damper opens the first air outlet, the damper and the first side wall of the casing are spaced apart to form a vortex cavity. A movable first partition is provided inside the vortex cavity, which divides the vortex cavity into a vortex duct and a return duct. Part of the airflow entering the vortex cavity circulates between the vortex duct and the return duct, mixing with the airflow at the fan outlet to generate self-excited oscillation and achieve diffused airflow. When the damper and the first partition are moved, part of the airflow entering the vortex duct forms a vortex airflow between the first partition and the damper, thereby changing the air outlet angle of the indoor air conditioning unit. Since the damper is used to open or close the first air outlet and is also reused as the cavity wall of the vortex cavity, the number of components in the indoor air conditioning unit can be reduced, thereby reducing manufacturing processes and the overall size of the indoor air conditioning unit.

The application provides a constant current module and application thereof. The constant current module comprises a high electron mobility field effect transistor based on a III-V compound and a source feedback resistor; the source feedback resistor comprises a built-in source resistor of the transistor or the built-in source resistor of the transistor and an external source resistor connected to the source. In the application, the source feedback resistor is arranged in the constant current module, so that the gain of the constant current module is reduced, the stability is improved, the high-frequency performance is improved, the ringing phenomenon is avoided, the transient response is not too slow, the pole frequency is more controllable, the probability of self-oscillation is reduced, the power density is controlled, the working temperature is reduced, the service life is prolonged, the knee voltage is obviously reduced, the influence caused by the production process error of the transistor is reduced or eliminated, and the yield is improved.

The present application relates to the technical field of vibration system, especially to a CD drive planar tension self-excited oscillation control system and a control method thereof; by connecting the photothermal elastic element and the passive elastic element to tension the vibration mass point, and combining with the light source irradiation to form the light irradiation area, a planar tension self-excited oscillation control system with simple structure and without external periodic excitation is constructed, the vibration mass point can be driven to continuously and stably self-excited oscillate under constant light, the system realizes self-sufficient energy and cable-free operation, has the ability to resist electromagnetic interference, and is suitable for microgravity and weightless environment; the control method of the present application constructs the CD strain equation and the vibration mass point motion equation based on the measured deformation curve of the photothermal elastic element, solves the target control parameter set through dimensionless processing, realizes the accurate design and pre-control of the system oscillation amplitude, frequency and motion trajectory, and each parameter can be independently or cooperatively adjusted, which significantly improves the controllability and applicability of the system.

This application discloses an indoor air conditioning unit and an air conditioner. The indoor air conditioning unit has a movable damper on its casing, which is used to open or close the first air outlet of the casing. The damper is located inside the casing, and the damper and the first side wall of the casing are spaced apart to form a vortex cavity. A movable baffle is provided inside the vortex cavity, which divides the vortex cavity into a vortex air duct and a return air duct. Part of the airflow entering the vortex cavity generates self-excited oscillation under the action of the baffle, achieving a gentle breeze. The other part of the airflow can circulate between the vortex air duct and the return air duct, thereby forming a vortex airflow, which changes the air outlet angle of the indoor air conditioning unit. Since the damper is used to open or close the first air outlet and also serves as the cavity wall of the vortex cavity, the number of components in the indoor air conditioning unit can be reduced, thereby reducing manufacturing processes and the overall size of the indoor air conditioning unit.

The application relates to an automatic high-frequency plastic heat sealing device, and belongs to the technical field of plastic heat sealing devices.The automatic high-frequency plastic heat sealing device comprises a bottom plate, an electronic tube self-excitation oscillator is fixed to the right side of a support frame, an electric push rod is fixed to the upper surface of the support frame through a mounting frame, the outer side of an output shaft of the electric push rod slides through the support frame and extends to the inside, and the heat sealing mechanism comprises a fixed plate, two first telescopic rods, two spring telescopic rods, a lower pressing plate, an upper electrode plate and a sliding assembly, the fixed plate is fixed to the outer side of the output shaft of the electric push rod. The automatic high-frequency plastic heat sealing device is provided with a full-automatic control system, the labor efficiency is remarkably improved, the electronic time-limit switch accurately controls the melting and cooling time, the product quality is improved, the low-loss coaxial oscillator enhances the output, the melting time is shortened, the overcurrent protection and spark protection devices improve the safety of the equipment, the push-pull type workbench is convenient to operate, and the production efficiency is improved.

The application provides a mining inner-outer double disturbance self-excited oscillation jet flow nozzle and operation method, which comprises a shell with a self-excited oscillation chamber, a mixing inlet communicated with the self-excited oscillation chamber is arranged on one side of the shell, a jetting outlet communicated with the self-excited oscillation chamber is arranged on the other side of the shell, a double-port pipe is connected to the mixing inlet, the double-port pipe comprises a vertical air inlet pipe and a horizontal liquid inlet pipe, the vertical air inlet pipe and the horizontal liquid inlet pipe are vertically communicated with a vertical mixing pipe, an X-shaped rotating flow core is arranged in the vertical air inlet pipe, the inlet of the horizontal liquid inlet pipe is arranged along the tangent direction of the flow channel of the vertical air inlet pipe, the self-excited oscillation chamber is a conical cavity, the small-diameter end of the conical cavity is communicated with the mixing inlet, the large-diameter end of the conical cavity is concave along the axis to form an inner recess, and the inner recess is communicated with the jetting outlet. High-frequency oscillation is generated in the self-excited oscillation chamber, which forms the "inner-outer double disturbance" atomization form together, induces more vortex energy, strengthens the cavitation effect of the nozzle, and effectively improves the atomization effect.

The application discloses a geothermal well sound-water synergic anti-blocking device and method. The device comprises a center flow pipe, a piston type tuning sliding sleeve, two main oscillation cavities, a shared secondary convergence coupling cavity, a reduced-diameter impact nozzle, a tuning mechanical vibration body, an outer wall thin-wall radiation window and a lateral high-pressure water nozzle. The high-pressure geothermal fluid forms near-frequency pulse jet flow through two main oscillation cavities and two groups of differential throttling throat pipes, and a composite pressure pulse containing a low-frequency beat frequency envelope is formed in the shared cavity. The composite pressure pulse impacts the tuning mechanical vibration body through the reduced-diameter impact nozzle, forming radial sound-water coupling vibration waves; the lateral high-pressure water nozzle sprays pulse water flow, which continuously disturbs, loosens and flushes the scale layer, particle deposition and blockages of the near-well fracture mouth and the near-well section of the main fracture of the hot dry rock geothermal well, and is beneficial to maintaining the long-term stability of the fracture conductivity.

The application discloses a power supply circuit and a semiconductor process equipment, a self-excitation oscillation circuit is used for generating a first voltage, each group of voltage doubling rectification circuits comprises two voltage doubling rectification sub-circuits, the output ends of the two voltage doubling rectification sub-circuits are connected with one of two power supply output ends respectively, the polarities of the voltages output by the two voltage doubling rectification sub-circuits connected with the same power supply output end are opposite, each selection circuit is connected with a group of voltage doubling rectification circuits, the selection circuit is used for transmitting the first voltage to the corresponding group of voltage doubling rectification circuits when being selected, and a switching control circuit is used for outputting selection signals to the two groups of selection circuits respectively, so that only one group of selection circuits is selected at the same time. Because the voltage received by the selection circuit is the first voltage which is lower, the selection circuit does not need to adopt a high-voltage relay which is high in pressure, and can adopt a MOS tube which is low in pressure, small in size and low in cost, so that the size and cost of the power supply circuit can be reduced.

This invention relates to a method for detecting the mass of ferromagnetic particles based on a magnetic rod sensor. The magnetic rod sensor has a detection end and a control end with a magnetic rod and an LC resonant circuit. The method includes: when the magnetic rod attracts ferromagnetic particles in oil onto an induction coil, the control end controls the LC resonant circuit to generate a self-excited oscillation signal related to the change in inductance of the winding; the control end analyzes the self-excited oscillation signal to obtain the resonant frequency of the LC resonant circuit, and then calculates the mass of the ferromagnetic particles attracted by the magnetic rod based on the resonant frequency; the control end sends out the calculated ferromagnetic mass as an analog signal or a digital signal. This invention improves detection sensitivity by using a magnetic rod formed by multiple magnets connected in series to form a larger attraction area and attraction magnitude, and by using several coils connected in series with opposite directions to form a winding. The method implemented based on the above-mentioned equipment can promptly understand the wear status of the monitored system or equipment.