122results about How to "Avoid loud noise" patented technology

The invention discloses a difference double-interference type optical fiber gyroscope based on birefringence modulation. The optical fiber gyroscope comprises a light source, a modulator, a coupler, an optical fiber ring, a polarization beam splitter, a first detector and a second detector, wherein the light source and the modulator are welded at a melting point O1 with an angle of 45 DEG; the modulator and a port A of the coupler are welded at a melting point O2 with an angle of 45 DEG; an end C of the coupler and one end of a polarization-maintaining optical fiber ring are welded at a melting point O3 with an angle of 0 DEG; an end D of the coupler and the other end of the optical fiber ring are welded at a melting point O4 with an angle of 90 DEG; an end B of the coupler and an input end of the polarization beam splitter are welded at a melting point O5 with an angle of 0 DEG; and two output ends of the polarization beam splitter are respectively welded to the first detector and the second detector. According to the invention, closed-loop control of the difference double-interference type optical fiber gyroscope is realized; and a wide-spectrum light source with very weak coherent characteristics is adopted, thereby avoiding strong noise brought by various stray wave interferences which are caused by strong coherent characteristics of a laser light source.

The invention discloses a differential dual-interference type closed loop fiber optic gyroscope based on birefringence modulation of a wide frequency light source. The differential dual-interference type closed loop fiber optic gyroscope comprises the light source, a first coupler, a second coupler, a first polarization beam splitter, a first modulator, a second modulator, a second polarization beam splitter, a fiber optic loop, a third polarization beam splitter, a first detector and a second detector. The differential dual-interference type closed loop fiber optic gyroscope has the advantages that closed loop control of the differential dual-interference type fiber optic gyroscope is realized; as the wide frequency light source with a very weak coherence characteristic is adopted, strong noise brought by various stray wave interference caused by a strong coherence characteristic of a laser light source is avoided; a SAGNAC effect is doubled; and the differential dual-interference type closed loop fiber optic gyroscope has a mature technical foundation and can satisfy a relatively high precision requirement.

The invention provides a photoelectric oscillator which comprises a DFB laser device, a delay optical path and a photoelectric mixing feedback loop. The DFB laser device is used for generating local oscillator optical signals. The delay optical path is used for delaying the local oscillator optical signals. The photoelectric mixing feedback loop is used for carrying out down-converting processing on the local oscillator signals and input optical carrier waves to obtain low-frequency electrical carrier waves, filtering the electrical carrier waves in a narrow-band mode, carrying out up-converting processing on the delayed local oscillator optical signals and the filtered electric carrier waves, and outputting optical carrier waves. Optical delay generated by the delay optical path and electrical delay generated by the photoelectric mixing feedback loop are matched so as to eliminate phase noise attached to the local oscillator signals on the output optical carrier waves. The method of electrical assistance is utilized, a Q value up to 1.4*10<7> is achieved equivalently, intracavity delay and gain are provided by an electric device, and sensitivity to environment factors caused by long optical fibers and loud noise caused by an optical amplifier are avoided.

The invention discloses an air conditioner as well as a frequency control method and device thereof. The method comprises the following steps of obtaining frequency variation of an existing compressor; determining target operation frequency according to the relationship of the temperature difference of the current room temperature and a set room temperature and a first set threshold value if frequency variation of the existing compressor is greater than zero and when operation frequency of the compressor regulated according to the frequency variation of the existing compressor is within a frequency hopping band range; determining target operation frequency according to the relationship of temperature difference of the current room temperature and the set room temperature and a second set threshold value if the frequency variation of the existing compressor is smaller than zero and when operation frequency of the compressor regulated according to the frequency variation of the existing compressor is within the frequency hopping band range; and controlling the compressor to operate according to the target operation frequency. The frequency control method can be applied to solve the problems such as great temperature fluctuation, frequent compressor lifting and the like caused by improper frequency hopping band processing in frequency control in the prior art.

This invention provides a low-noise reactor with its core made up of multiple lamination steel plates dipped with paint, in which, these plates have related leaning faces fixed by binders after leaning with each other directly or with multiple pads, paint binding the lamination steel plates on the leaning faces is removed, then a binder is filled between the leaning faces of the plates or between the lamination plates and the pads then to be cured.

A face seal is provided with a constriction ring around a rubber boot that constricts the normal outward bulging of the flex section of the rubber boot as it folds and tries to roll forward over itself during axial deflection. The constriction caused by the constriction ring provides for increased frictional hysteresis during compression and decompression of the boot flex section. This increased hysteresis increases the dampening capacity of the seal design and, therefore, reduces undesired vibrations and seal noise generation.

The invention discloses intelligent kitchen terminal equipment based on the internet. The intelligent kitchen terminal equipment based on the internet comprises a shell, a main fan, an exhaust duct, a control module, a man-machine interaction panel, an image acquisition unit and an audio directional acquisition unit, wherein the image acquisition unit comprises a camera, an image acquisition channel, an image acquisition hole and a purging motor; the audio directional acquisition unit comprises a first subunit and a second subunit; the first subunit faces a cooking activity area and is used for acquiring sound produced by cooking activity so as to avoid wind noises of the main fan as much as possible; and the second subunit faces an activity region of cooking operators, and is used for acquiring voices of the cooking operators to avoid the wind noises of the main fan as much as possible. The camera is prevented from being polluted by lampblack and water vapor, the video quality is high, and the sound recording effect is good.

The invention discloses a high-speed PMSM harmonic suppression control method based on an LC filter and an adaptive notch filter. The method comprises the following steps: 1) obtaining characteristicparameters of a high-speed PMSM; 2) according to the characteristic parameters of the high-speed PMSM obtained in the step 1), establishing a mathematical equation expression of the high-speed PMSM byadopting a differential equation so as to establish a mathematical model of the high-speed PMSM; 3) establishing a mathematical model of the high-speed PMSM with an LC filter; 4) obtaining a transferfunction of a motor control system according to the mathematical model of the high-speed PMSM with the LC filter established in the step 3), and then performing amplitude-frequency characteristic analysis according to the transfer function of the motor control system to obtain the resonant frequency of the PMSM; and 5) setting a self-adaptive wave trap according to the resonant frequency of the PMSM obtained in the step 4), and filtering a resonance peak at the resonant frequency through the self-adaptive wave trap. According to the method, the working efficiency, stability and anti-interference capability of a motor system can be effectively improved.

A linear driver is provided and particularly, but not exclusively, to a linear driver for use in the field of civil engineering or construction, for example in the formation of piles or piers as foundations. The driver includes a weighted sleeve slidable relative a driving member, and a valve arrangement to control the linear movement of the weighted sleeve relative to the driving member. Closing the valve arrangement serves to stop movement of the weighted sleeve and transfer momentum to the driving member without physical impact between the weighted sleeve and the driving member.

The invention discloses a horizontal pulverizer with shock-absorbing function, which comprises an outer drum, the outer drum is cylindrical, the bottom of the outer drum is left and right symmetrically fixedly connected with a shock-absorbing base, and the right side of the outer drum is provided with a feeding hole , the inside of the outer drum is connected to the inner drum through bearings, the inner drum is cylindrical, the right side of the inner drum is open, the inner side of the right end of the inner drum is fixedly connected with a retaining edge, and the retaining edge and the inner drum are connected by welding. There are several screening holes on the outer side of the middle part of the drum, and the inner side of the screening holes is fixedly connected with a screen mesh, and the screen mesh and the screening hole are connected by threaded connection. Compared with the prior art, the beneficial effects of the present invention are: the present invention is simple in structure, easy to use, can reduce the vibration caused by crushing during crushing production, avoid excessive noise, and at the same time, the device will be qualified when crushing and grinding. The raw materials are screened out without re-screening, which is worth promoting.

The invention discloses an underwater image enhancement method for optimizing CLAHE. The method comprises the following steps: (1) a preprocessing process; (2) an HE treatment process; (3) an adjustedCLAHE treatment process; and (4) image re-synthesis, and enhanced image output. According to the method, core parameters in a traditional CLAHE algorithm are optimized, so that the method is more suitable for an application scene of underwater image enhancement. The HE algorithm and the CLAHE algorithm are used in a mixed mode, the overall color of the image is recovered, detail features are moreobvious, and the phenomenon that noise points are large due to the AHE algorithm is avoided. The algorithm does not depend on a complex mathematical model, does not use a huge algorithm, is small incalculation amount, does not need training, is quick in execution, reduces the requirements for the performance of a processor, and is suitable for the transplantation and implementation of various types of underwater embedded platforms.

The optical disk player of the present invention is capable of controlling rotational speed of an optical disk, on the basis of a shape of the optical disk, so as to stably and efficiently write data in and read data from the optical disk. The optical disk player comprises: a motor for rotating the optical disk; and an optical pickup for irradiating a laser beam to the optical disk and receiving a reflected beam reflected therefrom. A CPU analyzes signals included in the reflected beam so as to recognize a shape of the optical disk. A servo processor controls rotational speed of the optical disk on the basis of the shape of the optical disk recognized by the CPU.

The invention discloses an industrial camera with good heat dissipation performance, relates to the technical field of industrial cameras, and aims to solve the problem of poor heat dissipation performance in the prior art. A containing box is arranged on one side of a machine shell. A cooling liquid container is mounted in a fixing ring; a water-cooling circulating pump is mounted above the cooling liquid container; a liquid inlet is formed in one end of the water-cooling circulating pump; a liquid outlet is formed in one end below the cooling liquid container; a chipset is arranged on one side of the interior of the machine shell. A host is arranged on the other side of the interior of the machine shell; an optical filter is mounted on one side of the host; heat dissipation bases are installed on the inner side of the host and the inner side of the chipset correspondingly, heat dissipation fins are arranged on one sides of the heat dissipation bases, a heat dissipation fan is installed between the host and the chipset, a coiled pipe is installed at the upper end of the interior of the machine shell, a first heat dissipation window is arranged above the machine shell, and a secondheat dissipation window is arranged above the containing box.

The present invention discloses a control method of an electromagnetic heating system. The control method comprises the following steps of: controlling an electromagnetic heating system to enter a first heating period and a second heating period, wherein each heating period comprises a discharge phase, a heating phase and a stop phase, in the discharge phase of the first heating period, a drive circuit is controlled to output M first pulse signals to a power switch tube, and in the discharge phase of the second heating period, the drive circuit is controlled to output N second pulse signals tothe power switch tube; and recording the number of pulses which cannot meet a preset condition in the M first pulse signals by employing a first counter to obtain a first counting value, and recording the number of pulses which cannot meet the preset condition in the N second pulse signals by employing a second counter; and determining whether the drive circuit is abnormal or not according to a first counting value and a second counting value so as to effectively detect the abnormal condition of the drive circuit and reduce the loss. The present invention further discloses an electromagneticheating system and an electromagnetic heating device.

The invention relates to the field of curtains, in particular to a transmission mechanism of an electric telescopic curtain and a telescopic curtain guide rail. A transmission mechanism of an electrictelescopic curtain comprises a first transmission mechanism, a guide rod and a second transmission mechanism, the first transmission mechanism comprises a driving belt gear, a first intermediate gearand a first synchronous gear, the driving belt gear is connected with the output end of a motor, and the driving belt gear is meshed with the first intermediate gear; one end of the guide rod is fixedly connected with a first guide gear, the guide rod is slidably sleeved with a second guide gear, and the first guide gear is engaged with the first intermediate gear; the second transmission mechanism comprises a driven belt gear, a second intermediate gear and a second synchronous gear, the second intermediate gear is meshed with the second guide gear, and the driven belt gear is meshed with the second intermediate gear. The curtain rail can be stretched to a specified size according to the length of a window, all gears are the same in rotating speed, transmission is stable, the service life of a belt is long, and synchronous opening and closing of a curtain are easily achieved.

The invention provides a vibration-absorbing type concrete stirrer convenient in cleaning and for a building. The vibration-absorbing type concrete stirrer comprises a base, wherein a vibration-absorbing device is arranged at the lower end of the base; a supporting seat is provided with a stirring drum, a top plate is fixed at the upper end of the stirring drum and a spring is connected and arranged between the stirring drum and the supporting seat; an agitator is fixed at the upper end of an inner cavity of a top seat; a water feeding pipe is arranged at the upper end of the inner cavity of the top seat; a discharging pipe is arranged at the lower end of the stirring drum in a communicating manner; a collecting dish is arranged on the base; an automatic feeder is arranged at the upper-left side of the base. The vibration-absorbing type concrete stirrer provided by the invention has the advantages that the stirring drum is set into a hopper shape and is arranged below the agitator, sothat fast mixing of concrete and water can be realized and simultaneously the discharging is convenient; in the stirring process, due to fast vibration of a vibrating motor, complete mixing and discharging are convenient, and the concrete can be prevented from being adhered to the inner wall of the stirring drum; the vibration-absorbing type concrete stirrer has the characteristics of simple structure, strong practicability and good mixing treatment effect.

The invention provides an anti-collision door sticker. The door sticker is that a soft rubber block is arranged on an elongated sticking base block. When the door sticker is used, the soft rubber block is sticked and fixed at the collided position between a door or a frame or a wall body through the sticking base block, direct collision between the door or the frame or the wall body can be relieved and buffered during opening and closing, and damage and produced noise are avoided.

The invention discloses a cooking utensil. The cooking utensil comprises a pot, a cover and a heating device, wherein the pot is provided with a cooking cavity with the open top; the cover is movablymounted to the pot between the closing position and the opening position, the cooking cavity is closed when the cover is at the closing position, the cooking cavity is opened when the cover is at theopening position, and the cover is provided with an air exhaust hole; the heating device is used for heating air in the cooking cavity so that the air is exhausted from the air exhaust hole after expanding due to heat, and after cooling of the air in the cooking cavity, negative pressure is formed in the cooking cavity. According to the cooking utensil provided by the invention, the effect of vacuum negative pressure can be achieved, so that the cooking effect of the cooking utensil is improved, the cooked food is more delicious, in addition, an air extracting pump does not need to be mounted,so that the structure of the cooking utensil is simple, meanwhile, the cost is reduced, and moreover, the problem that the air extracting pump is large in noise and short in life is solved.

The invention discloses a full-automatic ramie bidirectional stripping machine comprising a ramie conveyor, a front stripping machine and a rear stripping machine. The ramie conveyor includes a conveyor frame, a feeding conveyor, a ramie uniformizing device and a ramie feeding device, and the feeding conveyor, the ramie uniformizing device and the ramie feeding device are installed on the conveyorframe; the ramie stripping machine includes a hemp stripping machine frame, a ramie clamping and conveying device and a ramie stripping mechanism, and the ramie clamping and conveying device and theramie stripping mechanism are installed on the hemp stripping machine frame; the output end of the feeding conveyor is connected with the input end of the ramie uniformizing device, the output end ofthe ramie uniformizing device is connected with the input end of the ramie clamping and conveying device, and the output end of the ramie feeding device is connected with the input end of the ramie clamping and conveying device. According to a ramie stalk conveyor of the present invention, continuity of the ramie stalks, automatic completion of ramie uniformization, cutting, rolling and strippingcan be realized; and meanwhile, the ramie bidirectional stripping machine can realize bidirectional stripping of the ramie stalks through two ramie stripping devices staggered fore and aft, and the clamped and conveyed part of the ramie stalks can be stripped, thereby improving the utilization rate of the ramie stalks and improving the stripping efficiency from the ramie stalks to ramie fibers.