215results about How to "Amplitude stable" patented technology

The invention relates to a device and a method for generating a reference signal of a phase-locked amplifier of a millimeter wave attenuation measurement system. The device comprises a millimeter wave signal source, a first isolation attenuator, a second isolation attenuator, a millimeter wave and harmonic wave mixer, a first intermediate frequency amplifier, a belt-pass filter, an intermediate frequency fundamental wave mixer, a second intermediate frequency amplifier and an inductive voltage divider which are connected sequentially, wherein the inductive voltage divider is further connected with the phase-locked amplifier and a third intermediate frequency amplifier. An output end of the third intermediate frequency amplifier is connected to an input end of the phase-locked amplifier. The device and the method for generating the reference signal can ensure measurement accuracy of the phase-locked amplifier. In addition, in the device, the reference signal can be generated only by one millimeter wave mixer, so that cost of the millimeter wave attenuation measurement system is greatly reduced.

The invention discloses a reciprocating type micro-friction abrasion testing machine and belongs to a micro-friction and abrasion testing device. The testing machine comprises a bottom plate, and a bracket, a driving device, a loading device, a positioning and clamping device and a signal conditioning and data acquisition device which are arranged on the bottom plate, wherein the bracket at least consists of two side plates which are longitudinally fixed on the bottom plate; a lower sliding rail seat and a top cylinder seat are at least arranged between the two side plates. An exciter serves as a power source, the equipment is small in size and has high driving force and wide amplitude and frequency variation range, the signal is provided by a signal generation card, multiple driving signals are provided, the frequency and the amplitude are convenient to adjust, and the testing machine is easily controlled by a computer program; meanwhile, a clamp system for a fixation test is simple in structure, reliable in clamping and convenient to mount, and tests in multiple friction pair contact forms can be realized by replacing the clamp. The designed testing machine is high in precision and convenient to operate and provides a reliable experimental instrument for research of micro abrasion.

The invention provides a square-wave pulse laser device, which comprises a nonlinear amplification environment NALM and a pulse laser main oscillation cavity, wherein the nonlinear amplification environment NALM is used for performing intra-cavity pulse shaping on laser pulse; and the pulse laser main oscillation cavity is used for circularly oscillating a square-wave laser pulse sequence in the nonlinear amplification environment NALM and the pulse laser main oscillation cavity and generating and outputting square-wave laser pulse. The invention also provides a square-wave pulse laser generating method, which comprises the following steps of: inputting continuous laser to excite a working substance to generate primary laser pulse; and performing intra-cavity pulse shaping on the primary laser pulse through the nonlinear amplification environment NALM, and circularly oscillating the primary laser pulse in the nonlinear amplification environment NALM and the pulse laser main oscillation cavity to generate the square-wave laser pulse. According to the pulse laser device and the method provided by the embodiment of the invention, the pulse laser device can directly output the square-wave laser pulse and has the characteristics of self start and simple adjustment.

An optical recording/reproducing medium having grooves (2) formed along recording tracks and used for recording/reproducing when irradiated with light L with a specified wavelength λ, wherein the track pitch p of a groove (2) is at least 200 nm and up to 350 nm, and a ratio w_g/p between the width w_g of a groove (2) and a track pitch p is at least 0.24 and up to 0.67.

Power source module includes first stage DC/DC converter unit converts variable input DC voltage to stable DC output; second stage DC/DC converter unit with fixed duty ratio; control circuit controls output from first stage DC/DC converter unit, and provides driving pulse for second stage DC/DC converter unit with fixed duty ratio. The invented power source provides input voltage in wide range. Synchronous rectified drive signal with stable amplitude can be obtained through second stage DC/DC isolating transformer with fixed duty ratio. The said drive signal can drive synchronous rectification tube directly so as to realize synchronous rectification output. The invention is applicable to power source module in low voltage and large current in high efficiency.

A diode-pumped laser is disclosed with internal frequency doubling to prevent interfering power fluctuations in the laser radiation generated by the non-linear crystal at the start of the power adjustment in a simple and, therefore, inexpensive construction without power-reducing elements in the cavity or thermal effects having a negative impact on the laser behavior. The laser contains, as laser-active medium, a solid-state laser crystal with a temperature gradient directed substantially parallel to the cavity axis. The conversion of laser radiation of a fundamental laser wavelength into laser radiation of another wavelength is carried out by a non-linear optical crystal with a lower non-linear conversion efficiency than that required for achieving maximum power of the converted laser radiation. The laser can be used particularly for medical purposes, e.g., in the field of ophthalmology for coagulation of the retina as well as in the field of dermatology.

The invention relates to a power supply for achieving pulse microwave output employing a magnetron and a control method of the power supply. The power supply for achieving the pulse microwave output employing the 2.45GHz magnetron comprises a filament power supply, an anode negative high-voltage power supply and a controller. Output of the anode-supply high-voltage power supply of the 2.45GHz magnetron at a certain pulse repetition frequency and a modulated duty ratio is achieved under the condition of not changing heat-sink cooling of the anode, so that accurate and controllable microwave generation time and the maximal output power are achieved; and synthesis of output power multi-tubes of the 2.45GHz magnetron is achieved through control to the requirements of industrial high-power microwave output.

The invention discloses a micro-grid control method capable of significantly improving the electric energy quality of a micro-grid. The method can be realized by an Advanced f-P/V-Q controller. An Advanced f-P Drooping/V-Q Drooping algorithm link, a filter capacitor voltage loop and a filter inductance current loop are comprised. When a micro-grid system is in an island operation mode, through the changes of micro-grid voltage amplitude and frequency, the Advanced f-P/V-Q controller controls a micro-source to respond to the phenomena of the load change of the micro-grid, the output power fluctuation of other micro-sources and the like and to output the active power and the reactive power currently required by the micro-grid system, to stabilize the voltage frequency and amplitude of the micro-grid system, thus the electric energy quality of the micro-grid is significantly improved; and when the system is in a grid-connected mode, the Advanced f-P/V-Q controller automatically responds to the phenomena of the load change of the micro-grid, the output power fluctuation of other micro-sources and the like, and enables the micro-grid system to stably output the set power, and at present the voltage of the micro-grid system varies with the voltage of a distribution grid, thus the electric energy quality requirements of the micro-grid and the distribution grid are satisfied.

A robot system including: one or two robot arms which perform work on a target; a shape measurement device which is disposed on the robot arm and measures a shape of the target; and a controller which controls the robot arm based on the shape measurement device, in which the shape measurement device includes a projection device which projects striped pattern light onto the target, an image capturing unit which captures the image of the pattern light, and a processor which calculates the shape of the target based on the captured image by the image capturing device, and in which the projection device includes a light source device which emits linear laser, an optical scanner which generates the pattern light by reflecting the laser from the light source device and by scanning the target, and a scanner driver which outputs a driving signal to drive the optical scanner non-resonantly.

The invention provides a method capable of achieving direct current component and alternating current component separation in human body pulse wave sample signals and a pulse signal acquisition system based on wavelet decomposition and reconstruction. According to the pulse signal acquisition system, the sample frequency is set in the range from 100 Hz to 200 Hz, and the layer number of the wavelet decomposition and reconstruction is automatically selected; firstly, direct current components in an original sample data sequence are separated; secondly, an arithmetic mean value of a direct current component sequence is taken out to serve as a direct current signal with the constant amplitude; thirdly, an alternating current signal (pulse wave) with the more stable amplitude and phase position is separated from the original sample data sequence according to the direct current signal for the application such as blood pressure calculation, blood oxygen monitoring and hemodynamics PWV monitoring to use.

The invention discloses a temperature and coupling running controlling method of a double-compressor and double-refrigerating circuit refrigerator. The temperature and coupling running controlling method comprises the following steps: picking up current temperatures of a priority control compartment and a secondary control compartment; and monitoring the startup-shutdown state of a compressor in the priority control compartment: if the compressor in the priority control compartment is in a shutdown state, carrying out logic comparison on the picked current temperature of the secondary control compartment and a set starting temperature, a set shutdown temperature and set temperature offsets E1 and E2 to control the compressor to start up or shut down; and if the compressor in the priority control compartment is in a startup state, carrying out logic comparison on the picked current temperature of the secondary control compartment and a set starting temperature, a set shutdown temperature and set temperature offsets E3 and E4 to control the compressor to start up or shut down. When the temperature and coupling running controlling method is applied to the double-compressor and double-refrigerating circuit refrigerator with energy coupling, simultaneous starting and refrigerating time, i.e. coupling running time, of two refrigerating circuits can be prolonged, and the running efficiency of a system is improved.

The invention relates to a three-level type starting/electricity generator two-phase excitation constant slip AC starting control model and a control method thereof. According to the technical scheme, a two-phase symmetric exciting winding is used in a three-level type starting/electricity generator exciter stator, when a motor is started, two-phase alternating currents with phase mutual difference being 90 degrees are connected to the magnetizing exciter stator, the additional alternating current frequency of the magnetizing exciter stator is adjusted to keep the constant slip with the induction magnetic potential frequency of a motor rotor, so that it is guaranteed that the amplitude of three-phase alternating currents output by a magnetizing exciter is stable, and sufficient stable exciting currents are provided for starting of a main electricity generator. Accordingly, sufficient stable exciting currents are provided for starting of the main electricity generator, and it can be guaranteed that a three-level type starting/power generation machine is stably and reliably started.

This ivnention relates to a method and a cotnroller for vibration feeder with self-frequency adaptation and self-amplitude control. The controller consists of a monolithic computer, a photoelectric position sensor, an exciter, a display, a keyboard, an RS232 interface. The control emthod is based on phase feedback, and carried out by using a photoelectric position sensor to collect position and phase signals of the vibration feeder, using a computer to process the signals, sending them to the display and RS232 interface and the exciter, and actuating the feeder.

The invention discloses a PID (proportion integration differentiation) feedback based predistortion correction method. The method includes: respectively extracting a positive half amplitude, a negative half amplitude and a direct-current component of an acquired output signal of a power amplifier, and respectively performing PID feedback correction to enable the output signal of the power amplifier to keep stable along with change of time. In addition, on the premise of stable output of the power amplifier, a magnetic nanoparticle based non-contact temperature measurement method is applied to high-power LED (light emitting diode) junction temperature measurement. According to the PID feedback based predistortion correction method, amplification factor of the power amplifier is adjusted in real time to enable the positive half amplitude, the negative half amplitude and the direct-current component of the output signal of the power amplifier to keep stable along with change of time, and measurement basis is provided for long-time LED junction temperature measurement.

The invention discloses a self-adaptive digital active noise reduction framework. The framework comprises a reference microphone, a first analog-digital converter, a first high-pass filter and a feedforward self-adaptive filter which are connected in sequence. The framework further comprises an error sensor, a second analog-digital converter and a second high-pass filter which are connected in sequence. The output end of the first high-pass filter is further connected with a feedforward fixed filter, the output end of the second high-pass filter is connected with the feedforward self-adaptivefilter, the output end of the second high-pass filter is further connected with a feedback fixed filter, and after being superposed, signals of output ends of the feedforward fixed filter, the feedforward self-adaptive filter and the feedback fixed filter are subjected to digital-to-analogue conversion and output by a loudspeaker. Noise reduction waves generated by the fixed filters are superposedwith noise reduction waves generated by the self-adaptive filter, so that defects of pure self-adaptive framework in the aspect of noise reduction effect are overcome; an automatic amplitude controlcircuit is additionally arranged in an error microphone sampling channel so as to overcome the precision defect of fixed-point operation.

The invention provides a treatment method for a slurry continuous wave signal. The signal is resolved into superposition of a series of wavelet functions by adopting wavelet transformation, the higher frequency resolution is achieved on the low frequency part, and the higher time resolution is achieved on the high frequency part. The self-adaptability to the signal is achieved, and the details of the signal can be reflected. A measurement while drilling signal is prone to be influenced by various noise in the transmission process.

A method for measuring the threshold value of human nerve includes opening human skull, applying electric stimualting signal to the nerve to be measured, measuring the electromyographic signal of the muscle controlled by said nerve, and finding out the threshold value and relative parameters. Its system is composed of a nerve threshold stimulator, a digital electromyograph and a computer.

The invention relates to a novel nonlinear earthquake reduction device. The novel nonlinear earthquake reduction device can effectively dissipate energy introduced by a body and introduce the energy into the earthquake reduction device in a one-way mode, broadband earthquake resisting is achieved, resonance damage is avoided, and the novel nonlinear earthquake reduction device has suitable rigidity and damping capacity, and is stable in performance, compact in structure, variable in frequency, controllable in damage and easy to manufacture. A vibration absorber is mainly a horizontal earthquake absorbing device, the whole structure is in a long-strip shape, and the novel nonlinear earthquake reduction device comprises end fixing members (1), connecting pre-embedded pieces (2), silica-gel damping mats (3), nonlinear rigid springs (4), steel tube sliding ways (5) and a NES vibrator (6). The novel nonlinear earthquake reduction device can be used for interlayer earthquake isolation and basic earthquake isolation of an engineering structure, and can also be used for earthquake isolation of a mechanical device.

The invention discloses a BD1 (Beidou 1) and BD2 radio frequency compatible receiving method and device. The device mainly comprises a power module as well as an antenna, a low noise amplification module, a radio frequency module and a baseband signal processing module which are connected with the power module, wherein the low noise amplification module comprises an anti-interference filter, a first-level amplifier, a power divider, two narrow-band filters and two second-level amplifiers; and the radio frequency module comprises two down converters, two band-pass filters, two automatic gain controllers, two intermediate frequency dividers, four intermediate frequency filters, a frequency synthesizer and an analog-digital converter. The BD1 and BD2 radio frequency compatible receiving method and device can solve the compatibility problem in regional-to-global transition of a BD system, and the compatible receiving of signals of BD1 and BD2 is an effective path to realize the stable transition.