46results about How to "Precise frequency control" patented technology

The invention relates to a current-adjustable and PWM flicker control constant-current driving circuit, which comprises a power supply and protection circuit (1), an LED or LD module (2), an MCU control circuit (7), a constant-current driving and current sampling circuit (3), a reference voltage setting circuit (4), a current setting and flicker control circuit (5) and a feedback and compensationcircuit (6). The constant-current driving and current sampling circuit is used for realizing adjustment of current output. The reference voltage setting circuit is used for setting reference voltageof the output current. The current setting and flicker control circuit is used for setting a pulse or a constant current value and setting frequency and pulse width. The feedback and compensation circuit realizes current feedback and dynamic compensation of the system, achieves the purpose of stabilizing current output, and has the effects of improving the rising speed of output current and widening the width of the output current. According to the invention, the constant current or pulse current of the LED or LD module can be adjusted, PWM adjustment and flicker control of the pulse current can be carried out, and the requirement of constant current driving in an LED light source and an LD laser system in a machine vision system can be met.

The invention discloses a control circuit, a switching power supply and a control method. The control circuit is used for controlling a switching converter and comprises a status acquisition circuit and a control signal generation circuit. The status acquisition circuit is used for generating an error amplifying signal according to a feedback voltage and a reference voltage, carrying out slope compensation on the error amplifying signal through a slope compensation signal with a preset frequency, and comparing the error amplifying signal which has undergone slope compensation with a voltage ripple to output a status signal, wherein the voltage ripple changes synchronously with the current of an energy storage element of the switching converter. The control signal generation circuit is used for outputting a switching control signal according to the status signal to control the switching converter, wherein the switching control signal has the preset frequency. By carrying out fixed-frequency control with the voltage ripple changing synchronously with the current of the energy storage element of the switching converter as the parameter, the control accuracy of the switching converter is improved, and frequency control is more accurate.

The invention discloses tangential final-motion frictional wear test equipment. The equipment is characterized in that a lateral hydraulic piston connected with a data acquisition and control system is connected with a hinged shaft at the middle upper part of a vertical connecting rod; the upper end of the connecting rod is connected with one side of an upper test piece chuck through a cross bar; the other side of the upper test piece chuck is connected with a tangential displacement sensor fixed on the side wall of an experiment medium cavity; the upper test piece chuck is used for clamping a spherical test piece; a lower test piece chuck for clamping a plane test piece is arranged right below the upper test piece chuck; the lower test piece chuck is fixed at the bottom of the experiment medium cavity; the bottom of the experiment medium cavity is arrange on two longitudinal supporting rods; and a deformation sensor is arranged between the top of the longitudinal supporting rods and the bottom of the experiment medium cavity. The tangential final-motion frictional wear test equipment can effectively simulate the tangential final-motion friction and has the advantages of simple structure and high test precision, is convenient to maintain, can carry out a final-motion frictional test under the medium conditions, such as controllable high temperature, lubrication and liquid, and can provide more accurate and reliable test bases for designing, manufacturing and maintaining relevant parts.

The invention discloses a control method for frequency regulation of an electric power isolated network system. The control method is characterized by comprising the following steps of step 1, setting the permanent rotating-speed difference coefficient bp, PID parameters, frequency modulation dead zone 0.05Hz, and a frequency range from minus and plus 0.05Hz to minus and plus <theta>Hz for retrieving a frequency modulation module according to power grid requirements, wherein <theta> is a positive number greater than 0.05; step 2, detecting the current unit frequency by a speed regulator; step 3, obtaining a difference value <delta>f between the current unit frequency and a rated frequency 50Hz; and step 4, performing regulation according to the numerical value range of the frequency difference <delta>f. By adoption of the method, the problems of high frequency control error, low precision and instability of the electric power system, particularly the isolated network system can be solved; therefore, accurate and stable control of the power grid frequency is realized; the electric energy quality of the power system is ensured; power grid accident extension is prevented; and rapid recovery of the power grid in faults can be realized.

The invention relates to a double-fluid injector, which comprises a valve body, an injection mechanism and a travel adjusting mechanism, wherein the valve body consists of an upper valve body and a lower valve body which are fixedly connected to the upper end and the lower end of a middle valve body respectively; the travel adjusting mechanism is arranged in a cavity formed between the middle valve body and the upper valve body and is a micrometer head travel adjusting mechanism; and the injection mechanism is arranged in a cavity formed among the middle valve body, the lower valve body and the travel adjusting mechanism and is a double-fluid injection mechanism. The flow forms of double fluids in a mixing cavity are controlled by adjusting the flows and pressures of input gas and liquid,so that liquid is sprayed from a nozzle on the lower valve body in dot, line and mist forms. The double-fluid injector has a simple structure, long service life, high gas and liquid controllability, high injection accuracy and high working frequency, and can be applied to multi-fluid injection processes in preparation of semiconductor membranes, preparation of composite materials, electronic encapsulating, (MENS) systems, ink jet, spraying, lubrication, powder metallurgy, food processing, biomedicine, welding, rapid prototyping manufacturing, combustion, engines, chemical industry and the like.

The present invention provides one kind of intelligent sand mixing controlling method. The key point of the present invention includes establishing the mathematic model of the relation among sand temperature, facing sand/back sand amount, demolding time, and the amount of fast curing agent and slow curing agent; calculating the amount of curing agent and calculating the rotation speed of conveying pump. The present invention adopts mathematic model and curve fitting technology in fitting the nonlinear relation of pump flow rate, has the active effects of accurate material compounding, saving material and raised product quality.

The invention relates to an RLC measuring instrument. The CPLD technology is adopted for replacing a digital circuit to generate sine detection signals, chip resources on a CPLD development board are rich, PLLs are contained in the CPLD development board, and the frequency can be multiplied and divided conveniently. The RLC measuring instrument comprises a storage unit, a ROM table macroblock can be directly called, an SOPC can be used as a kernel, high-frequency test signals can be obtained conveniently, and the waveform quality of the sine detection signals can be improved. The invention further relates to a measuring method based on the RLC measuring instrument. The direct digital frequency synthesis technique is adopted, the frequency and the phase of the output sine detection signals can be accurately controlled, and meanwhile, the measuring instrument has the advantages that frequency switching time is short, the frequency resolution is high, the phase is changed continuously, phase noise and drifting are low, and integration and adjustment are easy.

The invention relates to a laser cavity ring-down gas spectral measurement system based on femtosecond optical frequency combing and belongs to the field of cavity ring-down gas spectral measurement. The system is composed of a cavity ring-down spectral measurement system, a measuring laser frequency stabilization system and a cavity length stabilization system. A femtosecond pulse laser serves as a frequency standard, measuring laser frequency and cavity length can be traceable to the time frequency standard, and accordingly high-precision cavity ring-down spectral measurement is achieved.

The invention discloses a microwave power source, a microwave plasma system, an ignition method and a self-tuning method. The microwave power source comprises: a microwave signal generator used for generating a microwave signal; a signal adjusting unit used for adjusting the amplitude and phase of the microwave signal and loading pulse signals with different frequencies and duty ratios; a semiconductor amplification unit; a signal transmission and load detection unit used for sending the microwave signal amplified by the semiconductor amplification unit to a load and detecting the sent microwave signal and a microwave reflection signal generated by the load to obtain a detection sampling signal; and a control unit used for receiving and analyzing the detection sampling signal so as to control the signal emission frequency of the microwave signal generator and/or control the adjusting mode of the signal adjusting unit according to the analysis result. According to the invention, automatic ignition frequency searching, an automatic ignition process and a self-tuning process are achieved, and the problems that existing traditional microwave plasma equipment is difficult to ignite automatically and work stably are solved.

The invention discloses a file equalization method for an IDFS. The method is realized by a file index classification module, a file transfer module, a file index search module, a file performance monitoring and task distribution module, and a configuration list of HLS live broadcast on-demand video optimization. The file index classification module is used for classifying and sorting the stored contents. The file transfer module realizes balanced file transfer without stopping the service. The file index searching module realizes the update of the file index on the premise that the file indexcan be cached, and at the same time, the file index searching module does not cause the fault that the file cannot be found. The file performance monitoring and task distribution module realizes storage equalization under the condition that the influence on the performance of the existing network system is reduced as little as possible. The configuration list of the HLS live on-demand video optimization realizes accurate control of the equalization frequency and the equalization speed. The method of the invention can realize the equalization of each storage capacity to the maximum extent andrealize the equalization transfer of files.

The invention discloses a wire take-up control method for a drawbench. The method is executed by a control device. The control device is used for generating a control instruction corresponding to a take-up motor and generating a control instruction for a stretching motor and/or a wire arrangement motor. The method comprises the following steps that a tension signal fed back by a tension detectiondevice is acquired, and an auxiliary frequency is calculated according to the tension signal; a frequency of the stretching motor is acquired, and a main frequency is calculated on the basis of the frequency of the stretching motor; the main frequency and the auxiliary frequency are summed to obtain a target frequency of the take-up motor; and a control instruction corresponding to the target frequency of the take-up motor is generated so as to control the frequency of the take-up motor of the drawbench. According to the wire take-up control method, through the process, the frequency can be accurately configured for the take-up motor in the drawbench according to the tension signal fed back by the tension device. The invention further provides a wire take-up control device for the drawbench and a storage medium.

The invention relates to an acoustic propagation system, which comprises a planar resonance circuit that comprises a planar resonance body and a permanent magnet, the planar resonance body comprises a metal layer and a flexible film substrate layer, and the metal layer is laminated on the flexible film substrate layer; wherein the planar resonance body comprises a plurality of planar resonance units which are distributed in an array. According to the invention, the integrated planar resonant body is designed, so that the problems that the structure occupied size is large and the sound vibration frequency is limited in a fixed range due to an independent structure in the prior art are solved. The planar resonance body comprises a plurality of planar resonance units, which are distributed in an array, so that accurate frequency control can be realized, and the sound quality is obviously improved.

The invention discloses an assembled frequency modulation transformer. The assembled frequency modulation transformer comprises a body; the upper part of the body is provided with a frequency modulation switch; the upper part of the body is provided with a plurality of transformation wiring ports; two sides of the bottom part of the body are respectively provided with a first fixing point and a second fixing point; the frequency modulation switch is provided with a fine-adjusting switch and a coarse-adjusting switch; the upper part of the frequency modulation switch is provided with an indicator lamp; and the transformation wiring ports set the voltage regulating values with various ranges. Because the frequency modulation switch of the assembled frequency modulation transformer is provided with the fine-adjusting switch and the coarse-adjusting switch and the upper part is provided with the indicator lamp, the frequency can be accurately regulated and controlled, and the frequency value is conveniently observed. Because the transformation wiring ports set the voltage regulating values with various ranges, the assembled frequency modulation transformer can be suitable for the requirements of different types of the instruments for the voltage.

An intrabody bioreactor for the tissue-engineered organ transplantation is composed of an external powder pump system and an internal catheter system. It can be used to pump the cell culturing liquid containing the self blood serum of organ receptor, seed cells and growth factors into the transplanted organ and promote its vascularization.

The automatic glue spraying and stamping device comprises a glue feeding body, a valve body and a firing pin, the valve body comprises a shell, a sealing piece and a limiting part, the limiting part comprises an upper limiting piece and a lower limiting piece, and the firing pin is controlled by electromagnetic signal induction. The invention belongs to the technical field of dispensing connection modes in high-speed stamping and application, and particularly provides a dispensing device which can accurately control the size, the flow, the position and the dispensing frequency in the dispensing process, can achieve gluing in the stamping process, can achieve high-frequency dispensing efficiency and long-time service life, can adjust the height, and is convenient to use. And the automatic glue spraying and stamping device is convenient to popularize and use.

A blanking sampling device for stamping comprises a sampling mechanism and a sampling frequency control mechanism, wherein the sampling mechanism comprises an upper die, a pressing rod, a rear pressing block, a sliding block, a sliding rail and a material receiving hopper; the upper end of the pressing rod is fixedly connected with the lower end face of the upper die, the upper end of the rear pressing block is fixedly connected with the lower end of the pressing rod, the rear pressing block is used in cooperation with the sliding block, and the sliding block is in sliding connection with the sliding rail; the sliding rail is fixed through a sliding rail seat, the material receiving hopper is fixedly connected with the sliding block through a connecting rod, and the rear pressing block can extrude the sliding block in the process that the rear pressing block is pressed downwards along with the upper die and enables the sliding block to drive the material receiving hopper to move from a material receiving station to a discharging station; and the sampling frequency control mechanism is configured to control the material receiving frequency of the material receiving hopper by controlling the position of the sliding block. Automatic sampling of the stamping blanking device for the chain parts is achieved, in the sampling process, the sampling frequency and the sampling number are accurately controlled according to a preset program, errors caused by manual sampling are avoided, and quality control over the chain parts is facilitated.

The invention relates to the field of molecular sieve preparation, and discloses a forming method and application of a molecular sieve adsorbent. The method comprises the following steps: (1) adding a mixture of a molecular sieve and clay into a ball pot filled with seed balls in batches; (2) adding water into the rolling-ball pot, so that the water content W1 of the small balls in the rolling-ball pot is maintained at 30-60wt%; (3) when the small balls grow to the particle size R of 0.15-2 mm, stopping feeding, controlling water adding, so that the water content W2 of the small balls in the rolling ball pot is maintained at 30-60 wt%, and continuously rolling for 0.5-3 hours; and (4) drying and roasting the pellets to obtain the formed molecular sieve pellets. The method for preparing the adsorbent provided by the invention is convenient to operate, improves the product percent of pass and the production efficiency, and is suitable for preparing various molecular sieve adsorbents formed by rolling balls.