43results about How to "Little impact from outside interference" patented technology

The invention relates to a device for detecting a precision wafer based on parallel optical flat splitting polarized beam and phase-shifting interferometry. The device comprises a light source, a spatial filter, a beam expander, a polarizer, a depolarizing dispersion prism, a parallel optical flat, a quarter-wave plate and an analyzer, wherein the light source, the spatial filter, the beam expander and the polarizer are arranged on a first optical axle in sequence, the analyzer, the quarter-wave plate, the depolarizing dispersion prism, the parallel optical flat and the surface of an externalobject to be measured are arranged on a second optical axle in sequence, and the first optical axle is perpendicular to the second optical axle.

A real-time clock synchronous error correction method for a cost-controlled intelligent electric energy meter, relating to the technical field of electric energy metering instruments, comprising the steps of: first creating an internal clock inside a single-chip microcomputer, and defining an array for storing external clocks; powering on the electric energy meter Initially set the internal clock after startup; then generate a second signal through the timer, and add 1 second to the internal clock every second; every time the internal clock is added for 10 seconds, the external clock and the internal clock are checked in turn , and perform corresponding synchronous error correction processing on the abnormal clock. The invention can enhance the anti-interference ability of the clock, effectively guarantee the accuracy of the real-time clock in the electric energy meter, and is stable and reliable.

The invention belongs to the technical field of medical devices and provides a pulse wave blood pressure simulator, which includes: a blood pressure simulation device for simulating human blood pressure signals, which includes a soft rubber tube filled with gas and elastically expandable and contractible, and a The extruding assembly of the soft rubber hose, the soft rubber hose is arranged in the extrusion assembly; the pressure sensor is used to detect the pressure in the soft rubber hose, which is connected with the soft rubber hose; the pulse wave simulation device is used to simulate the pulse wave signal of the human body, which includes An air pump that provides pulsed air flow; a controller, used to control the working status of the blood pressure simulation device and the pulse wave simulation device and to collect feedback information from the pressure sensor. The blood pressure simulation device, the pulse wave simulation device and the pressure sensor are all connected with the controller electrical connection. The pulse wave blood pressure simulator can truly and accurately simulate human blood pressure and pulse signals, and can be used to accurately detect blood pressure monitors. The present invention also provides a simulation method matched with the pulse wave blood pressure simulator.

The invention discloses a method for testing low-frequency voltage / current fluctuation parameters of a solar cell module. By placing the photovoltaic module under test in a dark room, applying a bias voltage, recording the bias current I and the bias voltage V, and testing the The voltage at both ends of the photovoltaic module is connected to the AC low-noise signal amplifier, and the low-frequency voltage fluctuation signal is collected and calculated to obtain the power spectral density data of the low-frequency voltage / current fluctuation of the photovoltaic module module under test; the point-frequency noise voltage value f is calculated separately n , RMS value of bandwidth noise voltage v n , 1 / f noise amplitude B, 1 / f noise corner frequency f c Parameters such as the noise spectrum value ratio μ, etc., are recorded in the low-frequency voltage / current fluctuation characteristic parameter table of the component under the bias current. The relevant information contained in the low-frequency voltage or current signal fluctuation signal proposed by the present invention can be used as one of the sensitive and non-destructive means for characterization and evaluation of solar cell life and reliability.

The invention provides a device for measuring the time of arrival of a high-bandwidth radio frequency signal. The device comprises the following parts: an electrooptical modulator connected with a radio frequency signal to be measured; a reference signal source comprising a femtosecond laser device and a low-noise radio frequency signal source, wherein the femtosecond laser device is connected with the electrooptical modulator, and is located in a phase-locked loop, and the low-noise radio frequency signal source is connected to the input end of the phase-locked loop; and a photoelectric detector connected with the electrooptical modulator. According to the device for measuring the time of arrival of the high-bandwidth radio frequency signal, which is disclosed by the invention, the extremely low-noise femtosecond laser device is locked onto the low-noise radio frequency source through a phase-locked loop technology; the reference signal source with excellent noise performance is modulated through the electrooptical modulator according to the radio frequency signal to be measured; time of arrival information can be demodulated only by measuring an amplitude value of the modulated signal, so that high-precision time measurement resolution is realized; and furthermore, a laser pulse string is little interfered and affected by the outside in a transmission process, so that introduced external noise is lower.

The invention discloses a special circuit for laser ranging and a distance measuring method based on the circuit. Microcontroller, pulse phase IP core, first ADC module, second ADC module, digital peripherals, programmable multi-phase phase-locked loop, power management module, and storage module; the photoelectric processing chip consists of the first amplifier and the second amplifier , capacitors and photodiodes; the laser driver chip consists of a power management module, a first low-dropout linear regulator, a second low-dropout linear regulator, a third low-dropout linear regulator, a power-on reset module, and a pulse generator , Programmable multi-phase phase-locked loop, digital logic module, signal error detection module. The invention has the advantages of high circuit integration, small area and little influence by external interference, greatly reduces the hardware cost of the circuit, and can realize long-distance and high-precision distance measurement.

The invention discloses a multi-contact electric switch, which comprises a casing, a first cavity is arranged on the upper part of the casing, and two left-right symmetrical pressing mechanisms are arranged in the first cavity. A second cavity is provided in the housing below the first cavity, and two symmetrical transmission mechanisms are arranged in the second cavity, and a third cavity is provided in the housing below the transmission mechanism on the left side. The third cavity is provided with a first selection mechanism, and the right end of the first selection mechanism communicates with a fourth cavity located below the transmission mechanism on the right side, and the device is simple in structure and easy to operate, and is equipped with multiple The contact can be set with multiple functions as required, and the contact can be adjusted by a button to adjust the desired function. It is simple and practical, and the device adopts a purely mechanical structure, which has high stability and is less affected by external interference.

The invention discloses an electricity-taking method and device for detecting battery internal resistance. The method comprises the following steps of: generating at least a positive supply circuit and a negative supply circuit by a detected battery to supply power for at least one detecting circuit; and performing sampling the positive supply circuit and the negative supply circuit accurately. By using the electricity-taking method and device for detecting battery internal resistance, two or more than two detected batteries can be detected by using one detecting circuit; and the internal resistance of the detected battery can be detected on line or off line in real time and ultra-high common-mode rejection ratio can be obtained; the external influence on the detection precision is small, and the precision error can be less than 0.1 milliohm; the electricity-taking method and device for detecting battery internal resistance are applicable to various detection environments.

Provided is a trimming method for elongated and upright trunks of pear trees. The method comprises following steps: creating a hedge frame mesh, filed planting of nursery stocks, cutting, bud picking, vertically binding lignified parts of new shoots to the mesh, bud-notching, basal angles and waist angles opening, thinning and branching, promoting formation of flower buds, and management of continued branchs of central branches and lateral branches. The trimming method for elongated and upright trunks of pear trees helps to realize high-density of plantation pear trees.

The invention discloses a terahertz detector based on a multilayer-single-layer graphene junction and a preparation method thereof. Conductive channels in the detector are composed of multilayer-single-layer graphene junctions connected with one another; the multilayer-single-layer graphene junction is an effective sensitive area for terahertz wave detection; under the irradiation of terahertz waves, the photo-thermo-electric effect electromotive force of the multilayer graphene is greater than that of the single-layer graphene, so that a combined photo-thermo-electric effect electromotive force dominated by the multilayer graphene is formed; the combined photo-thermo-electric effect electromotive force is output in a circuit in a voltage or current mode to finally obtain terahertz wave response. In addition, the combined photo-thermo-electric effect electromotive force is regulated and controlled through a gate piezoelectric field, and the responsivity and the sensitivity of the detector can be further improved. Compared with the prior art, by combining the respective advantages of the single-layer graphene and the multi-layer graphene, the responsivity of the detector can be effectively improved, so that terahertz detection with high response speed and high responsivity is realized at room temperature.