884 results about "Varistor" patented technology

The invention discloses an electric energy metering box fault prediction method and system based on big data analysis, relates to the technical field of smart power grids, and solves the problems of progressive aging missing detection and instantaneous interference misjudgment caused by dependence on single parameter threshold alarm and fault positioning misalignment caused by multi-source data isolated analysis in the prior art. According to the scheme, electrical, environment and equipment state parameters are collected in real time through a multi-dimensional sensing network; the error drift of the mutual inductor is dynamically predicted based on an LSTM-Kalman filtering model, and core breakdown early warning is realized in combination with wavelet transform; outputting a corrected resistance value and a fault mark by using a BP neural network; predicting the life of the piezoresistor by adopting a gradient boosting decision tree and fusing lightning overvoltage characteristics; the transient interference is suppressed through the combination of a Transform self-attention mechanism and dynamic time warping; according to the method, the aging detection precision and the complex environment adaptability are remarkably improved, the misjudgment rate is reduced, and the multi-fault associated positioning and active defense capability is realized.

The invention relates to the technical field of electrical fault detection, in particular to a voltage-sensitive device damage diagnosis system combined with pulse test, which comprises the following modules: an original signal acquisition module for inputting pulse sequences to a voltage-sensitive device, respectively recording voltage response signals and current response signals under each pulse sequence, and generating a response signal set; and performing wavelet decomposition on the voltage response signal and the current response signal based on the response signal set. According to the method, the pulse sequences are input, and the voltage response signals and the current response signals under the pulse sequences are recorded, so that data acquisition covers different working states, and feature missing possibly caused by a single test point is reduced. A wavelet decomposition mode is adopted, a voltage response signal and a current response signal are divided into different frequency intervals, separation of high-frequency and low-frequency characteristics is facilitated, local abnormal signals are not covered by global characteristics, and the capability of analyzing short-time fault characteristics is enhanced.

The invention provides an optimization method and an optimization device for electrical performance of a ZnO piezoresistor based on O2 heat treatment. According to the method, O2 is introduced into the ZnO varistor under the condition of heat treatment, and oxygen vacancies in the ZnO varistor are reduced under the oxygen atmosphere, so that the donor concentration is reduced, the carrier concentration is reduced, and the electrical performance of the ZnO varistor is remarkably improved. Besides, the optimization device provided by the invention is used for the heat treatment step in the electrical performance improvement process of the ZnO varistor, and the front and back surfaces of the ZnO varistor can be in full contact with gas in the heat treatment process, so that the electrical performance is uniformly and effectively improved.

The invention relates to the field of voltage dependent resistor welding equipment, in particular to a voltage dependent resistor welding device which is characterized in that a triangular block, a pushing block, a driving assembly and a lifting assembly are matched with one another, in the fixing and butt joint process of the voltage dependent resistor, the voltage dependent resistor is extruded, and pins of the voltage dependent resistor are expanded, supported and bent through the triangular block; and the pins of the piezoresistor are aligned with the jacks on the circuit board, so that the piezoresistor and the circuit board can be quickly butted, and the welding efficiency of the piezoresistor is improved. According to the invention, the triangular block, the pushing block, the driving assembly and the lifting assembly cooperate with each other, and the piezoresistor is extruded in the process of fixing and butting the piezoresistor, so that the triangular block expands and bends the pins of the piezoresistor, and the pins of the piezoresistor are aligned with the jacks in the circuit board; rapid butt joint of the piezoresistor and the circuit board is facilitated, and the welding efficiency of the piezoresistor is improved.

The invention discloses a piezoresistor assembling device, and belongs to the technical field of electronic component manufacturing equipment. The problems that existing piezoresistor assembly mostly depends on manual or semi-automatic equipment, production efficiency is low, consistency is poor, all mechanisms are lack of effective cooperation and need manual intervention, resistor insertion deflection is prone to occurring, sand filling is uneven, and cover plate correction precision is low are solved. The device comprises a shell feeding mechanism, a resistor feeding mechanism, a cover plate feeding mechanism, a material inserting mechanism, a sand filling mechanism, a cover plate assembling mechanism, a driving mechanism, a supporting mechanism and a control system. The supporting mechanism supports all the mechanisms, the driving mechanism drives the shell to move at the stations of the material inserting mechanism, the sand filling mechanism and the cover plate assembling mechanism, the control system coordinates all the mechanisms to act, and all the mechanisms sequentially complete feeding of the shell, the resistor and the cover plate, insertion of the resistor into the shell, sand filling and cover plate assembling. The device is mainly used for automatically completing full-process assembly of the piezoresistor, continuous automatic production is achieved, and the assembly efficiency and the product consistency are improved.

The invention discloses a piezoresistive pressure sensor chip and a preparation method thereof, and belongs to the technical field of micro-electromechanical systems. The piezoresistive pressure sensor chip comprises a substrate, the back of the substrate is etched with a cavity, the center of the cavity is provided with a cross-shaped mass block, and four hollow islands and four peninsula are arranged along the linear direction of the cross-shaped mass block; a plurality of groups of piezoresistor strips are arranged on the front surface of the substrate, each group of piezoresistor strips comprises a first piezoresistor strip component arranged close to the center and a second piezoresistor strip component arranged close to the side wall of the cavity, and the first piezoresistor strip component forms an internal Wheatstone bridge through a first metal lead group; the second piezoresistor strip component forms an external Wheatstone bridge through a second metal lead group; the glass is arranged on the substrate back. The piezoresistive pressure sensor chip can measure the pressure of a micro-pressure section, can bear high overload equivalent to a plurality of times of the full scale, and has the advantages of high sensitivity, good linearity, high precision, good dynamic performance and the like.

A sintered body has a first end face and a second end face opposite to each other in a first direction and a first side face and a second side face opposite to each other in a second direction. A first end face electrode is disposed on the first end face except for end portions of the first end face in the second direction. A second end face electrode is disposed on the second end face except for end portions of the second end face in the second direction. A first side face electrode is disposed on the first side face except for end portions of the first side face in the first direction. A second side face electrode is disposed on the second side face except for end portions of the second side face in the first direction.

The invention belongs to the field of MEMS sensors, and discloses a high-temperature-resistant MEMS pressure sensor chip and a packaging structure thereof. The chip is provided with an SOI substrate, an AlN layer and a SiO2 layer from bottom to top, a plurality of P-type piezoresistors are arranged on the uppermost layer of the SOI substrate and are symmetrically distributed at the stress concentration position of the edge of the elastic diaphragm; a channel which continuously penetrates through the AlN layer and the SiO2 layer is arranged above the P-type piezoresistor; a metal Pad is arranged in the channel; the upper end of the metal Pad is located on the uppermost layer of the high-temperature-resistant MEMS pressure sensor chip, and the lower end of the metal Pad is in contact with the P-type piezoresistor. According to the invention, the relatively thick buried oxide layer can resist a high-temperature severe environment, and an AlN heat dissipation material with a high heat conductivity coefficient is deposited, so that rapid heat dissipation at a high temperature is ensured; and meanwhile, the stability and the reliability of the sensor are improved by adopting leadless packaging, and the packaging density is further optimized.

The invention belongs to the technical field of MEMS resonance sensors, and particularly relates to a real-time liquid flow rate monitoring sensor and method based on an MEMS plane resonance technology. Wherein the fan-shaped sensing plate is an arc plate, a central supporting beam is arranged at the rear end of the middle part of a small arc-shaped edge of the fan-shaped sensing plate, an electrothermal resonance excitation thin beam and a piezoresistive frequency reading thin beam are arranged on the left side and the right side of the fan-shaped sensing plate, and an electrothermal excitation resistor is embedded in the electrothermal resonance excitation thin beam; a piezoresistor is embedded in the piezoresistive frequency reading thin beam; according to the invention, the MEMS resonance technology is applied to the micro flow channel, and the high-precision measurement of the flow velocity of the fluid is realized through the frequency deviation characteristic of the torsional mode resonance generated by electromagnetic excitation under the action of the fluid.

The invention relates to a piezoresistive sensor. In particular, the present disclosure relates to piezoresistive sensor elements and piezoresistive pressure sensors that detect mechanical stresses acting on a membrane. The piezoresistive sensor element (100) comprises a substrate which, in operation, is subjected to a mechanical stress in response to a measured variable to be measured, a first array of at least four sensitive varistors (114), where the sensitive varistors (114) are arranged on the substrate and connected to form a first Wheatstone bridge for generating a first bridge signal, and a second array of at least four sensitive varistors (114) arranged on the substrate and connected to form a second Wheatstone bridge for generating a second bridge signal. A second array of at least four insensitive varistors (122), where the insensitive varistors (122) are connected to form a second Wheatstone bridge for generating a second bridge signal, where the stress sensitivity of the sensitive varistors (114) is higher than the stress sensitivity of the insensitive varistors (122), and wherein an output signal of the piezoresistive sensor element (100) is generated based on a difference of the first bridge signal and the second bridge signal.

The invention relates to the technical field of pressure sensors, and discloses a piezoresistive multi-range MEMS pressure sensor and a processing method thereof. The piezoresistive multi-range MEMS pressure sensor comprises: a pressed diaphragm; the mass blocks comprise a central mass block and a fixed mass block; the insulating layer is clamped between the pressed diaphragm and the mass block; the piezoresistor is arranged on one side, deviating from the mass block, of the pressed diaphragm; the at least two supporting frames are located in the pressure groove, each supporting frame surrounds the center mass block and is spaced from the center mass block, the supporting frame adjacent to the center mass block is connected with the center mass block through a first connecting beam, and the supporting frame adjacent to the fixed mass block is connected with the fixed mass block through a second connecting beam; every two adjacent supporting frames are connected through a third connecting beam. The piezoresistive multi-range MEMS pressure sensor disclosed by the invention is simple in structure and easy to process, and not only realizes multi-range acting force detection, but also realizes micro-range high overload measurement.

The invention relates to the technical field of stand-by power supply monitoring, in particular to an output stability monitoring method for a stand-by power supply for an elevator, which comprises the following steps of: judging whether the output stability of a power supply to be tested is abnormal or not by connecting a piezoresistor test loop and utilizing temperature change curve comparison conditions of a piezoresistor under different output working conditions; calculating a performance separation characterization index under each output working condition by using the temperature increment curve relative to the ambient room temperature; analyzing and determining a performance local separation power supply according to an index sequence consisting of the performance separation characterization indexes; and finally, determining an abnormal battery pack according to the internal resistance detection result of each battery pack under the determined disengagement characteristic dominant working condition. And furthermore, the output performance fluctuation condition of the battery pack in the switching operation process of different remaining electric quantities is indirectly quantified, and the dynamic guarantee capability of the standby power supply under the full working condition is comprehensively reflected.

The utility model discloses a power supply input surge protection and isolation device, which comprises a piezoresistor, a surge decoupling power resistor and a TVS (Transient Voltage Suppressor) tube which are sequentially connected in series, and a self-adaptive surge control circuit which is connected with the surge decoupling power resistor in parallel, when surge overvoltage occurs, the TVS tube is firstly broken down, and transient large current flows through the adaptive surge control circuit; the surge decoupling power resistor is used for enabling the passing surge current to generate relatively large voltage drop after the TVS tube is broken down; the self-adaptive surge control circuit comprises a first MOS tube which is used for conducting transient large current passing through a TVS (Transient Voltage Suppressor) tube; when the voltage drop on the MOS tube is greater than the breakdown voltage of the voltage-regulator tube, the voltage-regulator tube is broken down to trigger the conduction of the triode; when the voltage-regulator tube is broken down, the triode is conducted, so that the GS voltage drop of the first MOS tube is reduced, and the first MOS tube is turned off; when the sum of the clamping voltage of the TVS tube end and the voltage drop of the surge decoupling power resistor exceeds the minimum action voltage of the piezoresistor, the piezoresistor acts, so that high-energy transient interference flows through the piezoresistor, and surge protection is realized. According to the utility model, the surge protection and isolation protection functions of the input end of the power supply can be effectively realized, and the safety and stability of the use of the power supply are ensured.

The invention provides a method and device for increasing the rated current breaking frequency of a direct-current solid-state circuit breaker and application of the method and device, and aims to solve the problem that the breaking frequency of an existing direct-current solid-state circuit breaker is limited due to over-temperature damage caused by performance degradation after multiple current impacts of a piezoresistor and difficult measurement of the junction temperature of a power device. The system comprises a junction temperature prediction module based on a physical information neural network, an auxiliary energy absorption module and a power device voltage clamping module. The junction temperature prediction module is used for accurately predicting the junction temperature of the power device in real time by fusing a physical thermal model and a neural network; the voltage clamping module suppresses turn-off overvoltage; and the auxiliary energy absorption module is started when the junction temperature is close to the limit to absorb residual energy. According to the design, turn-off energy is reasonably distributed, the impact frequency and strength of the piezoresistor are reduced, the service life of the piezoresistor is remarkably prolonged (for example, the service life is prolonged by about 10 times under the impact of 200A), then the rated breaking frequency of the solid-state circuit breaker is greatly increased, and the solid-state circuit breaker is low in cost, high in reliability and suitable for scenes such as a direct-current power grid.

The invention relates to the technical field of SPD lightning protection, in particular to an intelligent SPD lightning protection detection system. The system comprises a data acquisition module used for acquiring leakage current, voltage and temperature of a piezoresistor; the lightning protection analysis module is used for analyzing the dispersion degree of the leakage current of the piezoresistor and the change trend of the leakage current, and determining the damage degree of the piezoresistor in combination with the temperature range of the piezoresistor and the dispersion degree of all elements in the leakage current coupling sequence; the method comprises the following steps of: analyzing the complexity and the voltage change trend of abrupt change data in the voltage of the varistors, and combining the similarity of the voltage change trends between the varistors connected in parallel to determine the voltage anomaly of the varistors; and the lightning protection detection module is used for judging the lightning protection detection precision at the current moment. According to the invention, the problem that the SPD lightning protection detection system cannot prevent lightning surge and power frequency voltage from damaging electrical equipment is solved, and the reliability of the SPD lightning protection detection system is improved.

The invention discloses a micro MEMS piezoresistive pressure sensor and a preparation method thereof, and belongs to the technical field of piezoresistive pressure sensors. Comprising a base layer, a substrate layer, a bottom silicon layer, a buried oxide layer, a device layer and a metal layer which are stacked from bottom to top, the bottom silicon layer, the buried oxide layer and the device layer form a peninsula-rod beam reinforced pressure sensing diaphragm; the peninsula-rod beam reinforced pressure sensing diaphragm comprises a peninsula, a connecting beam, a stepped rib plate and a central diaphragm; the peninsula is arranged on the upper surface of the central diaphragm, the stepped rib plate is located on the lower surface of the central diaphragm, the rod beam is arranged along the diagonal line of the central diaphragm, and the square island is arranged at the central position of the central diaphragm; and the stepped rib plates are positioned on four sides of the central diaphragm. The peninsula-rod beam reinforced pressure sensing diaphragm is adopted, the peninsula improves the output voltage of the sensor, the rod beam relieves the phenomenon that the displacement of the pressure sensing diaphragm is excessively increased under high stress, the step-shaped rib plate enables a piezoresistor area to generate stress concentration, and the sensitivity and stability of the piezoresistive pressure sensor are improved.

The invention discloses a method for eliminating bias signals during stress measurement of a piezoresistor and a CMOS chip, and belongs to the field of signal processing. According to the invention, at least one piezoresistive element in the Wheatstone bridge circuit is an adjustable resistor; if the piezoresistor generates a bias signal during stress measurement, the bias signal generated due to various conditions is eliminated by adjusting an adjustable resistor in the Wheatstone bridge circuit, so that when the pressure-sensitive chip is normally used, the measurement requirement can be met by externally connecting a microvolt-level power supply voltage and a small-range electric terminal, and the measurement precision is improved; and the power consumption of the pressure-sensitive chip is also greatly reduced by using the microvolt-level power supply voltage.

The invention relates to a high-g-value MEMS acceleration sensor chip based on an eight-beam structure. The piezoresistive MEMS high-g-value acceleration sensor with the eight-beam structure solves the problem that an existing accelerometer cannot meet the characteristics of high g value, high sensitivity and the like at the same time. The piezoresistive acceleration sensor with the eight-beam structure comprises a silicon-based frame fixed on a glass bottom plate, a cantilever beam and a mass block suspended in the center of the silicon-based frame through the cantilever beam, a piezoresistor forming a Wheatstone bridge is arranged on the cantilever beam, and the thickness of the silicon-based frame, the thickness of the cantilever beam and the thickness of the mass block are equal. The device is reasonable and simple in structure, has the characteristic requirements of good overload resistance and the like, and avoids the problem of failure in a severe impact environment; and an equal-thickness design is adopted, so that the manufacturing process is relatively simple, and the method is suitable for high-range acceleration sensors.

The invention discloses a high-stability radiation-resistant LED lamp constant-current source driving circuit, which comprises a surge protection circuit, an over-temperature and over-current protection circuit, a voltage transformation and rectification circuit and a constant-current source voltage regulation circuit, and is characterized in that the surge protection circuit adopts a gas discharge diode and a piezoresistor which are packaged by ceramics to improve the radiation resistance of the circuit; the surge protection circuit is connected with the transformation rectification circuit and is used for suppressing high-voltage pulses and shunting high voltage to realize overvoltage protection; the voltage transformation and rectification circuit and the over-temperature and over-current protection circuit are connected with the constant current source voltage regulation circuit, the voltage transformation and rectification circuit is used for transforming voltage and converting the voltage into direct current, and the over-temperature and over-current protection circuit cuts off a power supply when detecting abnormal high temperature or overlarge current to prevent the circuit from being damaged due to overheating or over-current; and the constant current source voltage regulating circuit is used for providing stable current output to drive the LED lamp. The LED lamp constant current source driving circuit has over-current, over-voltage and over-temperature protection functions while improving the irradiation resistance of the LED lamp constant current source driving circuit.

The invention discloses a nano-material piezoresistor and a preparation method thereof, and belongs to the technical field of piezoresistors, the preparation method of the nano-material piezoresistor comprises the following steps: S1, preparing raw materials for preparing the piezoresistor by mole percent: 94 to 96 percent of ZnO, 1.0 to 1.5 percent of Bi2O3, 0.5 to 1.5 percent of Co3O4, 0.3 to 0.8 percent of Mn2O3, 1.0 to 3.0 percent of Sb2O3 and 0.3 to 0.8 percent of NiO; s2, additives except ZnO are mixed, deionized water and a dispersing agent are added to prepare additive slurry, the additive slurry is dried and smashed after being sanded, and additive powder is obtained; s3, mixing ZnO with the additive powder, adding deionized water, a dispersing agent and a binder, and performing ball milling and refining in a ball mill to obtain total slurry; and S4, carrying out spray granulation, water-containing aging and dry-pressing molding on the total slurry, carrying out glue removal treatment on a green body subjected to dry-pressing molding, then carrying out high-temperature sintering, grinding and flattening, then carrying out heat treatment, coating silver electrodes on the upper and lower end surfaces, and coating insulating glaze on the side surfaces to obtain the piezoresistor. Wherein the dispersing agent improves the dispersity of the nano-powder, and the nano-powder has application prospects.

The utility model relates to the technical field of electrical protection devices, in particular to a surge protection device with a temporary overvoltage protection function, which comprises a piezoresistor assembly, an inductor and a switch assembly, the piezoresistor assembly is connected with the switch assembly in parallel, and two ends of the inductor are respectively connected with the piezoresistor assembly and the switch assembly. The switch assembly comprises a conduction switch, a combination switch, a resistor R1 and a capacitor, the conduction switch is in linkage connection with the combination switch, the conduction switch is connected with the capacitor in series, the resistor R1 is connected with the combination switch and the inductor in series, and one end, away from the conduction switch, of the capacitor is connected with the combination switch and the piezoresistor assembly; when the conduction switch is closed and the capacitor is fully charged, the combination switch is conducted. By means of the arrangement, the surge protection device can be prevented from being damaged by impact when overvoltage occurs; when surge voltage occurs, the surge protection device can effectively discharge the surge voltage, and the safety of electric equipment is protected.

The invention provides a power panel assembly based on output noise suppression and ripple attenuation. The power panel assembly comprises an input EMI electromagnetic compatibility module, a core power conversion module and an output noise suppression module. The input EMI electromagnetic compatibility module comprises a composite anti-surge circuit, the composite anti-surge circuit is formed by connecting a transient voltage suppressor diode, a metal oxide varistor and a self-recovery fuse in series, the clamping voltage of the transient voltage suppressor diode is 85 V, the peak power consumption is larger than or equal to 1500 W, the nominal voltage of the metal oxide varistor is 100 V, and the self-recovery fuse is connected with the transient voltage suppressor diode. The through-flow capacity is greater than or equal to 5kA; the core power conversion module comprises an isolation DC / DC power conversion unit and a three-dimensional stacked LC filter circuit, and the isolation DC / DC power conversion unit comprises at least one hot backup module, supports 9-36V input voltage and outputs multiple independent voltages.

A pressure sensor (1000) and a preparation method therefor and an air conditioning device. The pressure sensor (1000) comprises: a silicon substrate (100), the silicon substrate (100) comprising a first surface (101) and a second surface (102) opposite to each other, and the second surface (102) being provided with a cavity (150); a plurality of doped leads (120), the plurality of doped leads (120) being arranged in the silicon substrate (100); a plurality of varistor (130), the plurality of varistors (130) being electrically connected to the plurality of doped leads (120), respectively; a plurality of contact plugs (140), the plurality of contact plugs (140) being electrically connected to the plurality of doped leads (120), respectively; and a sealing cover (200), the sealing cover (200) being fastened on the silicon substrate (100) and forming a closed cavity (300) with the silicon substrate (100); the sealing cover (200) comprises a bonding portion (201); the sealing cover (200) is bonded and connected to the silicon substrate (100) by means of the bonding portion (201); the orthographic projection of the bonding portion (201) on the silicon substrate (100) is located between the orthographic projections of the varistors (130) and the contact plugs (140) on the silicon substrate (100); the surface of each varistor (130) facing the sealing cover (200) is exposed to the closed cavity (300); and in a first direction (Z), the distance between a third surface (121) of each doped lead (120) and the first surface (101) is greater than the distance between the surface of each varistor (130) facing the sealing cover (200) and the first surface (101).

A protective device that includes a thermal fuse and a metal oxide varistor (MOV) fuse positioned in series downstream of a main breaker, wherein a transformer's primary windings are positioned upstream from the MOV fuse and downstream of the thermal fuse.

A pressure sensor, relating to the technical field of sensors. The pressure sensor comprises a first substrate (21) and a second substrate (22) arranged opposite to each other, and a cavity (23) located between the first substrate (21) and the second substrate (22). The first substrate (21) comprises a pressure-sensitive film (211), and bonding rings (212), piezoresistors (213) and conductive columns (214) which are arranged on the side of the pressure-sensitive film (211) close to the second substrate (22). In the orthographic projection on the second substrate (22), each piezoresistor (213) is located within the range of the cavity (23) and close to the edge of the cavity (23), the corresponding bonding rings (212) are arranged on the side of the piezoresistor (213) distant from the center of the cavity (23), the bonding rings (212) are at least partially adjacent to the piezoresistor (213), and the piezoresistor (213) is connected to the corresponding conductive column (214). In a direction in which the first substrate (21) points to the second substrate (22), the height of the bonding rings (212) is greater than that of the piezoresistors (213). Also disclosed is a preparation method for the pressure sensor.

The invention provides a pressure and temperature cooperative measurement method for a piezoresistive MEMS pressure sensor, and the method comprises the following steps: S1, switching a resistor connection mode of an MEMS header of the piezoresistive MEMS pressure sensor through an MOS switch, and obtaining pressure and temperature signals in a time-sharing manner; s2, eliminating the influence of pressure on temperature measurement by using the equivalent resistance Req; and S3, based on the pre-stored temperature-pressure characteristic curve, compensating the temperature drift error in real time through a digital algorithm. According to the invention, cooperative measurement of pressure and temperature is realized by using a piezoresistive MEMS sensor gauge head piezoresistor, and calibration and compensation of temperature and pressure are realized through a digital algorithm; the design difficulty and process requirements of the piezoresistive temperature and pressure integrated sensor chip on the piezoresistive MEMS sensor header and the signal conditioning circuit are reduced, the measurement precision of temperature and pressure is improved, and the development and manufacturing cost of the piezoresistive temperature and pressure integrated sensor chip is reduced.

The invention discloses a direct-current power generation system and a control method thereof, which innovatively adopts a photovoltaic and energy storage double-cascade architecture and combines an intelligent protection and coordination control strategy. The system comprises N photovoltaic cascade subunits and M direct current energy storage modules, and each unit is provided with a bypass protection device. Each photovoltaic cascade subunit is integrated with an MPPT controller, an isolation converter and a bypass protector containing a piezoresistor and a diode; the energy storage module adopts a non-isolated DCDC conversion circuit, and a matched energy storage bypass protector is integrated with a bidirectional power electronic switch, a piezoresistor and a mechanical isolation switch. The technical problems of large voltage fluctuation, low system reliability, difficult maintenance and the like of a traditional direct current system are effectively solved, the service life of equipment is prolonged while the system stability is improved, and the system is particularly suitable for medium-high voltage direct current power supply scenes.

The invention relates to a ceramic sensor for monitoring the internal state of a battery and a preparation method of the ceramic sensor. The ceramic sensor comprises a ceramic substrate with a cavity structure, a pressure sensitive element which is arranged in the ceramic substrate and comprises a cavity structure, and a temperature sensitive element which is arranged in a non-cavity structure area in the ceramic substrate, wherein the pressure sensitive element is a capacitive pressure sensitive element which is composed of a cavity structure, a first pressure sensitive electrode arranged on the upper surface of the cavity structure and a second pressure sensitive electrode arranged on the lower surface of the cavity structure, or the first pressure sensitive electrode and the second pressure sensitive electrode are arranged in the cavity structure. The pressure sensitive element is a piezoresistive pressure sensitive element which is composed of a cavity structure, a Wheatstone bridge and a piezoresistor, wherein the Wheatstone bridge and the piezoresistor are arranged on the inner surface of the cavity structure. The lithium battery internal state monitoring sensor overcomes the defects of an existing lithium battery internal state monitoring sensor in the aspects of high temperature resistance, corrosion resistance and high reliability, and a new scheme is provided for lithium battery internal state monitoring and similar harsh environment sensing.

The present invention belongs to the technical field of thin film tensile testing devices, and particularly relates to a plastic thin film tensile testing device, including: a detection bottom plate, two moving plates are slidably connected to the upper end of the detection bottom plate in the horizontal direction; a stretching mechanism, which is arranged at the upper end of the detection bottom plate and is used to drive the two moving plates to move away from each other; a clamping mechanism, which has two and is symmetrically arranged on the relative sides of the two moving plates and is used to clamp and fix the plastic thin film. The clamping mechanism includes a fixed block fixedly connected to the side wall of the moving plate. By setting a length adjustment mechanism in the present invention, during the clamping process, for plastic thin films of different thicknesses, the downward sliding distance of the pressing block is also different, so that the pressure received by the piezoresistor below the pressing block is different, and the stretching parameters for the plastic thin film can be adaptively adjusted according to the thickness of the thin film, making the detected tensile strength of the plastic thin film more consistent with the actual performance.

The invention relates to the technical field of equipment foundation vibration detection, in particular to an equipment foundation for measuring self vibration or deflection through resistance change and a measuring method. The equipment foundation comprises an alignment device and a supporting device, piezoresistor elements are installed at the four corners of the top end of the alignment device, and the supporting device comprises a contact plate, a spring shock absorber and an equipment pedestal. According to the method, the vibration or deviation condition of an equipment pedestal is monitored in real time through a piezoresistor element, the accurate sensing of the basic state of the equipment is realized by utilizing the inverse ratio relation between resistance change and pressure change, and the quantitative relation between the resistance change quantity and the displacement quantity of the equipment pedestal is established through laboratory calibration. And when the change of the resistance value exceeds a preset threshold value, an alarm signal is sent to an integrated platform, so that rapid fault early warning is realized. According to the invention, the digital inspection of the equipment foundation is realized, the vibration or deflection state can be timely and automatically sensed, the safe and stable operation of the equipment is effectively guaranteed, and the management efficiency and reliability of the equipment are improved.