387 results about "Self excited oscillation" patented technology

The invention discloses a double-closed-loop control circuit of a micromechanical gyroscope and belongs to the field of guide or control devices based on a Coriolis effect. The circuit is used for closed-loop control of driving and detection modes of the micromechanical gyroscope. A simplified self-oscillation closed-loop control circuit based on automatic gain control (AGC) is employed for the driving mode of the circuit, and the frequency stability and amplitude stability of the micromechanical gyroscope in the driving mode can be effectively improved; and a six-order continuous band-pass Sigma Delta M closed-loop control circuit for the detection mode has six-order noise reshaping capacity, and the signal to noise ratio (SNR), linearity and zero-bias stability of a system detection signal can be improved. The double-closed-loop control circuit of the micromechanical gyroscope is easy to control and simple, the accuracy of a system is improved, the SNR of the system is high, and the system is self-adaptively adjusted and high in stability.

A semiconductor integrated circuit is provided with an external interface circuit, which includes a clock generation circuit for generating a synchronous clock signal to establish synchronization between data input and output through input and output of a data string sectioned at fixed intervals. The clock generation circuit includes a self-excited oscillator circuit serving as an oscillation source for the synchronous clock signal, and a control circuit for trimming the oscillation frequency of the self-excited oscillator circuit. The control circuit detects the sections made at the fixed intervals to the data string, measures the section interval based on an oscillation output of the self-excited oscillator circuit, and controls the oscillation frequency of the self-excited oscillator circuit to match the measurement value to a target value. With such a structure, any required frequency can be oscillated in a self-excited manner using a data string sectioned at fixed intervals using SOF packets or others instead of an oscillator.

An EUV light source of the present invention is capable of using a saturable absorber stably and continuously in a high heat load state. A saturable absorber (SA) device is disposed on a laser beam line to absorb feeble light, such as self-excited oscillation light, parasitic oscillation light or return light. SA gas from an SA gas cylinder and buffer gas from a buffer gas cylinder are mixed to be a mixed gas. The mixed gas is supplied to an SA gas cell via a supply pipeline, and absorbs the feeble light included in the laser beam. The mixed gas is exhausted via an exhaust pipeline, and is sent to a heat exchanger. The mixed gas, cooled down by a heat exchanger, is sent back to the SA gas cell by a circulation pump.

The invention relates to a device and a method for immovable-string type packer-free sliding-sleeve hydraulic-jet pulsed acid fracturing, belonging to the field of oilfield exploitation and relating to the device and the method for carrying out acid fracturing in a reservoir of an oil / gas well. The device comprises a guide head, a porous tubing nipple, a one-way valve, a first lower nipple, a first centralizer, a first spray gun, a second centralizer and a first upper nipple in sequence from bottom to top, wherein the one-way valve is used for realizing the closing and opening of the device, and the first spray gun is provided with a self excited oscillation nozzle for realizing hydraulic-jet pulsed perforating and acid fracturing. According to the invention, by utilization of a hydraulic entrainment packing effect produced by high-speed pulsed jet to carry out acid fracturing packing, the advantages of simple structure, safety and reliability are achieved; more layers can be subjected to acid fracturing by descending the device for acid fracturing in one step, balls are thrown stepwise to open a sliding sleeve so as to realize the stepwise acid fracturing of multilayer sections of the reservoir by an immovable string, and meanwhile, hydraulic perforating, hydraulic self-packing and pulsed acid fracturing can be realized at the same time; and by means of producing higher fluctuant stagnation pressure on a casing pipe and a well wall, a directional perforated hole can be formed rapidly, and compact belts generated due to explosion of a perforating bullet are prevented for the perforated hole.

In tuning a PID controller for a process in a feedback control system, a method is provided for bringing the system into symmetric self-excited oscillations for measuring the frequency and the amplitude of the oscillations, and tuning the controller in dependence on the measurements obtained. A control algorithm (modified relay feedback test) is introduced into the system in series with the process to excite self-excited oscillations in the system. Data and formulas are given for the computation of the specific parameter of the modified relay feedback test and for tuning the parameters of the PID controller. An apparatus for performing the method is disclosed.

The present invention is to provide a heat pipe which is high in heat transfer performance and reliability and can be low priced, compact and lightweight, and has flexibility, and a computer provided with the heat pipe. At least a part of a conduit (1) constituting a container of a self-excited oscillation heat pipe is formed in a shape having flexibility such as a waved bent shape. Alternatively, at least a part of the container of the self-excited oscillation heat pipe is formed of a material having flexibility such as super elastic alloys.

The invention discloses a multifunctional self-excited oscillation abrasive water jet generating device, which comprises an upstream nozzle, a downstream nozzle, an adjusting screw, a resonance cylinder, a first end cover and a second end cover. The device is characterized in that: the left part of the inner wall cavity of an upstream nozzle bush is provided with a metal threaded bush, and the outer wall of the upstream nozzle is matched with the inner wall of the resonance cylinder; the adjusting screw passes through a connecting screw cap and is sequentially in fit connection with the central hole of the first end cover, a locking screw cap and the metal threaded bush; the upstream nozzle is arranged on the right middle part of the inner wall cavity of the upstream nozzle bush, and the downstream nozzle is arranged between the right end of the resonance cylinder and the second end cover; the right end of the upstream nozzle, the left end of the downstream nozzle and the inner wall of the resonance cylinder positioned between the upstream nozzle and the downstream nozzle form a resonance chamber; and an air inlet formed on the resonance cylinder and an adjusting screw mounting hole are communicated with the resonance chamber. The device has simple structure, and is convenient for operation; the device has multiple testing functions; and compared with other jet generating devices, not only the experiment time can be greatly shortened, but also the experiment expenditure can be saved.

An ultrasonic motor comprises a piezoelectric vibrating member having a detecting polarized portion for detecting a drive signal having a drive frequency of the detecting polarized portion and a driving polarized portion for receiving the drive signal to oscillate the piezoelectric vibrating member in self-excited oscillation to produce a drive force. The detecting polarized portion is disposed at a portion of the piezoelectric vibrating member for undergoing maximum deformation in at least one vibration mode of oscillation of the piezoelectric vibrating member. An amplifying circuit amplifies the drive signal detected by the detecting polarized portion and inputs the amplified signal to the driving polarized portion to oscillate the piezoelectric vibrating member.

The invention discloses an automatic gain control (AGG) self-excited oscillation driving circuit of a micro-solid modal gyroscope, which comprises an oscillation circuit formed by five parts including a charge amplifier, a phase shifter, an amplifier, a band-pass filter and an automatic gain controller, wherein a gyroscope vibration signal is firstly received and enhanced by the charge amplifier, and then phase adjustment is carried out on a signal output by the charge amplifier by the phase shifter, so that the self-excited oscillation condition of a closed loop drive circuit can be met; the signal is amplified by the amplifier, and then frequency-selecting is carried out on the amplified signal by the band-pass filter; after passing through the band-pass filter, the signal enters the automatic gain controller; the automatic gain controller is used for controlling gain according to the difference value between the obtained signal amplitude value and reference signal amplitude value; and finally, a sine driving signal with constant amplitude and stable frequency can be obtained, and a whole closed loop drive system is ensured to be stable. The AGG self-excited oscillation driving circuit can be used for providing the driving signal with constant amplitude and stable frequency to the micro-solid modal gyroscope, so that the problems of the existing closed loop drive circuit can be solved.

The invention belongs to the technical field of application for aeronautic and astronautic power system, and relates to a flame stabilization technology for the combustion chamber of an engine based on a concave-cavity flame stabilizer, aiming at solving the problem of self-excited oscillation existing in conventional concave-cavity flame stabilizers. According to the invention, plasma exciters are installed at the upstream, the front wall, the bottom wall, the rear wall, the downstream and the flue nozzle of a conventional concave-cavity flame stabilizer; the plasma exciters are used for generating unbalanced plasmas via air discharge; and the electric field force inductively generated by the unbalanced plasmas and the released heat generate a control effect on a concave-cavity flow field so as to reduce concave-cavity resistance and suppress concave-cavity self-excited oscillation, and generate activation effects such as excitation, dissociation and ionization on an injected fuel so as to further increase combustion efficiency.

A switching power supply device that can reduce switching loss to obtain high efficiency. Additionally, the number of components of control circuits and the cost of switching elements can be reduced, with a transformer made compact and lightweight. In this switching power supply device, one end of a series circuit comprising a primary winding of the transformer, an inductor, and a capacitor is connected to a junction of a first switching circuit and a second switching circuit. The other end of the series circuit is connected to an input power source. A secondary winding of the transformer is connected to a rectifying and smoothing circuit including a rectifying element. In addition, in order to perform a self-excited oscillation, there are arranged first and second control circuits. The first control circuit controls a time elapsing until the first switching circuit turns on after the generation of a voltage in a first driving winding of the transformer and a time elapsing until the first switching circuit turns off. Similarly, the second control circuit controls a time elapsing from the generation of a voltage in a second driving winding of the transformer to the turn-on of the second switching circuit and a time elapsing until the second switching circuit turns off.

In tuning a controller for a process in a feedback control system, a method is provided for bringing the system into asymmetric self-excited oscillations for measuring the frequency of the oscillations, average over the period value of the process output signal and average over the period control signal and tuning the controller in dependence of the measurements obtained. An element having a non-linear characteristic is introduced into the system in series with the process and set point signal is applied to excite asymmetric self-excited oscillations in the system. An algorithm and formulas are given for identification of the process model having the form of first order plus dead time transfer function. PI controller settings are given as a function of the dead time / time constant ratio. An apparatus for performing the method is disclosed.

The invention discloses a current transformer secondary circuit monitoring module and method, and a specific transformer acquiring terminal. The monitoring module comprises: a first communication unit which communicates with a second communication unit in the specific transformer acquisition terminal; a current detection unit which detects the load current of the current transformer secondary circuit; a signal applying unit which applies a high-frequency voltage signal to the current transformer secondary circuit; a resonant unit which resonates when the high-frequency voltage signal is applied to the current transformer secondary circuit; an inverter which constitutes a self-excited oscillation circuit with the resonant unit; a micro-control unit which realizes data acquisition, flow control and signal control. The current transformer secondary circuit monitoring module and method, and the specific transformer acquiring terminal, based on the impedance characteristic of the current transformer secondary circuit, realize the normal connection, open circuit, and short circuit of the current transformer secondary circuit, and the state monitoring of a short-circuit electric energy meter.

An immersion nozzle for continuous casting which enables improvement in quality of a slab surface and increase in the efficiency of casting by suppressing the self-excited oscillation of a flow in a mold without using a complicated mechanism such as a swirl flow generating immersion nozzle is to be provided. A first immersion nozzle for continuous casting is a nozzle comprising a cylindrical body and a pair of outlet ports formed to face each other in a side wall in the vicinity of a bottom part of the cylindrical body, wherein a ridge-shaped projection extending parallel with the discharge direction projected on a cross section of the nozzle is formed on an inner surface of the bottom part, which is formed in a waterfall basin-like recessed shape having a maximum depth of 5 mm to 50 mm. A second immersion nozzle for continuous casting is a nozzle comprising a cylindrical body and a pair of outlet ports formed to face each other in a side wall in the vicinity of a bottom part of the cylindrical body, wherein each sectional area of the outlet ports vertical to a discharge direction projected on a cross section or longitudinal section of the nozzle is decreased toward an exit.

A backlight driving circuit includes a voltage-regulating circuit, a self-excited oscillation circuit, a transformer, a rectifying circuit and a filtering circuit. The voltage-regulating circuit is used for receiving an input voltage and adjusting the input voltage into a DC voltage. The self-excited oscillation circuit generates an oscillation voltage according to the DC voltage. The transformer includes a first primary winding assembly and a secondary winding assembly. The first primary winding assembly is connected with the self-excited oscillation circuit for receiving the oscillation voltage, so that the secondary winding assembly is induced to generate an AC output voltage. The rectifying circuit is used for rectifying the AC output voltage into a DC driving voltage. The filtering circuit is connected to the rectifying circuit and plural LED strings for filtering the DC driving voltage, so that the plural LED strings are driven by the filtered DC driving voltage.

The embodiment of the invention discloses a micro-power DC-DC power supply and a manufacturing method thereof. The power supply comprises a drive control circuit which receives an input voltage and generates two groups of pulse-width modulation (PWM) drive waveforms having the same amplitude and a phase difference of 180 degrees, wherein the PWM drive waveforms are used for driving a push-pull switch in a push-pull conversion circuit connected with the drive control circuit to be turned on alternately; the push-pull conversion circuit uses the alternate turning on of the push-pull switch to enable a power output transformer to realize voltage conversation; the power output transformer is connected with an output rectifying circuit to output direct current voltage through the output rectifying circuit without using the saturated characteristic of a magnetic core of the power output transformer to realize the turning of a self excited oscillation circuit; and the power output transformer works in an unsaturated state and therefore, can transfer energy with the highest efficiency.

A self-oscillating switch-mode amplifier amplifying an input signal into a power output signal comprising an integrator for integrating the difference between the input signal and the output signal and a hysteretic comparator with thresholds which are modulated according to absolute value of the input signal. When the thresholds are quadratic function of the absolute value of the input signal, the switching frequency of the self-oscillating amplifier can be substantially constant.

The invention discloses a device and a method for measuring the volume of an irregular object. One side of a cavity of a Helmholtz resonator is provided with a door through which an object to be measured is put in or taken out and which is provided with a compaction mechanism; eight (or a plurality of) pipelines are uniformly distributed on the periphery of the upper end of the cavity; and a speaker is arranged in the middle of the cavity, and a microphone is arranged near one corner of the cavity and is connected with an amplifying circuit to form self-oscillation, so that the resonance frequency is generated. The method comprises the following steps of: putting the object to be measured in the cavity, wherein the resonance frequency of the object to be measured changes, and the variable quantity depends on the volume of the object to be measured which is put in the cavity; and sampling, expanding, quantifying and calculating the cycle of the resonance frequency by an electronic technology to obtain the volume of the object to be measured. The device can measure the volumes of solid and liquid which have any specific gravity; air is used as a medium, so the device is clean; the device measures the object with a small gap, or hole and does not influence the result value; and the device is easy to operate, and can be made into a small portable device, so the device is easy to popularize and use.

The invention provides a capacitance detecting circuit, which comprises the capacitance pressure sensor, the multi-way switch and the capacitance frequency converting circuit. The capacitance pressure sensor converts the outside pressure exchanging signals into the capacitance changing values; the multi-way switch switches the capacitances of the two sides; the capacitance frequency converting circuit is the self-exciting oscillator circuit and converts the measured capacitance signals output by the multi-way switch into the frequency signals. The invention adopts the multi-way switch and the same square-wave self-excited oscillator to sample and fully makes use of the charging performance of the capacitance and avoids the interference of the AC power supply. The invention also protects the capacitance pressure transmitter adopting the above capacitance detecting circuit.

The invention provides a volumetric heat exchanger with a self-excited pulsating enhanced heat exchange function and a working method thereof. The volumetric heat exchanger comprises a shell, a partition plate, a heating medium inlet pipe section, a heating medium outlet pipe section, a refrigerating medium inlet pipe section, a refrigerating medium outlet pipe section, a heat exchange pipe, hoses, a flow limiting valve, a self-excited oscillation device and a pulsating hydraulic transmission device. According to the volumetric heat exchanger with the self-excited pulsating enhanced heat exchange function, a pulsating jet is produced by the heating medium when the heating medium passes through a Helmholtz resonant cavity of the self-excited oscillation device; by utilization of the pulsating hydraulic transmission device, the pulsating jet is effectively converted into beneficial vibrations of the heat exchange pipe; compared with that of the stable-state flowing condition, the heat exchange efficiency of the volumetric heat exchanger is improved by 30%; as the heat exchange efficiency is improved, the heat transfer area of the heat exchange pipe and the material consumption are reduced; and the volumetric heat exchanger is compact in structure, convenient to mount, and applicable to ship waste heat recovery, power station oil transportation, chemical engineering heating, and the like.

The invention provides a helicon wave plasma enhanced chemical vapor deposition unit, belonging to the technical field of plasma processing units, in order to achieve the stability and effective feed-in of radio-frequency power and effectively prevent the mode of the helicon wave plasma from hopping. The technical scheme of the invention is as follows that: the helicon wave plasma enhanced chemical vapor deposition unit comprises an external high-voltage power supply, an antenna for exciting the helicon wave plasma, an insulating dielectric tube, a high-vacuum cavity, a coil and an auxiliary coil, wherein the insulating dielectric tube is provided with an air inlet and an inlet air controlling device, and the high-vacuum cavity is provided with a ring-shaped nozzle and a heater; a self-excited radio-frequency oscillating circuit is connected between the external high-voltage power supply and the antenna for exciting the helicon wave plasma. By coupling the radio-frequency electromagnetic field with the helicon wave plasma in a self-excited oscillation manner, the invention can effectively prevent the mode of the helicon wave plasma from hopping, make the generated helicon wave plasma more stable and exploit new development potential for the application of the helicon wave plasma; and the invention further has the advantages of simple circuits, convenient adjustment and low construction cost.

A driving apparatus and a driving method are disclosed that are capable of uniformly lighting each entire fluorescent tube irrespective of the length or number of fluorescent tubes when simultaneously driving a plurality of fluorescent tubes in a fluorescent tube lighting apparatus. When two inverter circuits having respective transformers are provided at both ends of a fluorescent tube to light the fluorescent tube by push-pull driving, feedback windings of transformers not used in self-excited oscillation of each inverter circuit are connected together, with the transformer connection that connects together the feedback windings being either in-phase or in opposite phase, and the method of connection for fluorescent tubes connecting to secondary windings of each transformer can be changed in accordance with that connection method.

There is disclosed a semiconductor laser device characterized in that an electric current path from a p-type cap layer to a p-type cladding layer has a ridge stripe consisting of at least three semiconductor layers, wherein each layer has a different band gap, a top width of the p-type cladding layer is 2.5 mum or smaller, and a differential resistance of the device at a working current is 8 OMEGA or smaller. According to the present invention, a self-excited oscillation type semiconductor laser device and a real-guide type high power semiconductor laser device which have a low resistance and the high reliability at a high temperature can be provided.

The invention belongs to the field of oilfield exploitation, and particularly relates to a device and a method for performing acid fracturing in an oil and gas well reservoir stratum. The device comprises an upper conversion nipple, a centralizer, a spray gun, a lower conversion nipple and a guide joint which are connected in sequence, wherein the upper end of the conversion nipple is connected with a construction tube string. According to the device and the method, acid fracturing packing is performed by using a hydraulic entrainment packing effect produced by high-speed pulsating jet, the packer of the conventional acid fracturing tool is not required, and the problem of high probability of invalidation due to multiple setting and unblocking of the packer in the conventional tool is avoided; the depth for acid fracturing in the stratum can be increased by performing the acid fracturing using pulsating jet, so that the length of the fracturing fracture is increased; the device has a simple structure and is safe and reliable, the construction method is mature, and the construction cost is lower than that of the conventional technology; a water layer can be prevented from being penetrated in an acid fracturing process by adjusting the arrangement direction of a self-excited oscillation nozzle on the spray gun; a high-speed pulsating jet is formed through the self-excited oscillation nozzle arranged on the spray gun; a directional perforating hole is quickly formed and a compaction zone produced by perforating bullet explosive perforation is avoided.