405 results about "Varistor" patented technology

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.

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.

The invention belongs to the technical field of high-voltage electric appliance material preparation, and particularly relates to a zinc oxide resistor disc and a preparation method and application thereof. The preparation method comprises the following steps: (1) pre-sintering zinc oxide powder; (2) mixing the zinc oxide powder obtained in the step (1), an auxiliary agent and a dispersion liquid, and carrying out ball milling to obtain slurry; the particle size D50 of the slurry is 0.8-1.2 [mu] m, and the dispersity is greater than or equal to 95%; (3) performing spray drying and granulation on the slurry to obtain granulation powder; (4) carrying out molding and first sintering on the granulated powder to obtain a resistor disc semi-finished product; the first sintering adopts sectional sintering; and (5) forming an electrode layer on at least one surface of the resistor disc semi-finished product by adopting a vacuum sputtering and / or electrophoretic deposition process, and performing secondary sintering and annealing. The contact resistance of the zinc oxide resistor disc is less than or equal to 5m omega; and after 1000 hours of aging in a 85 DEG C + 85% RH environment, the leakage current increase is less than or equal to 2 [mu] A, and the performance degradation rate is less than or equal to 5%.

The invention relates to the technical field of power electronics, and discloses an alternating-current static switch topology with a buffering function and a design method of the alternating-current static switch topology. The alternating-current static switch topology comprises a bridge circuit and a buffer circuit, the buffer circuit comprises a first resistor, a first capacitor and a piezoresistor, the first resistor and the first capacitor are connected in series and then connected to the two ends of the bridge circuit in parallel, and the piezoresistor is connected to the two ends of the bridge circuit in parallel. According to the alternating-current static switch topology, the IGBT transistors of the bridge circuit achieve circuit mu s-level rapid opening and closing switching, and opening and closing rapidity is guaranteed; when the IGBT transistor of the bridge circuit is switched off, the piezoresistor of the buffer circuit and the RC circuit absorb the peak voltage of the IGBT transistor when the large current is switched off, so that the IGBT transistor is prevented from generating relatively high voltage stress due to system inductive reactance, the safe and stable work of the IGBT transistor in the bridge circuit is ensured, and the reliability and the stability of the application of the alternating current static switch are improved.

The invention provides a power converter, and belongs to the technical field of power electronics. In the scheme provided by the invention, the lightning protection unit in the power converter comprises a piezoresistor and a gas discharge tube which are connected in series. Therefore, the action voltage of the lightning protection unit can be effectively increased on the premise that the action voltage of the piezoresistor is not increased, and it is ensured that the lightning protection unit can be suitable for the high-voltage power converter. Moreover, by connecting the divider resistor in parallel with the gas discharge tube, flexible voltage division of the piezoresistor and the gas discharge tube can be realized, so that the model selection flexibility of the piezoresistor and the gas discharge tube is effectively improved. Besides, in a lightning stroke scene, the voltage at the two ends of the gas discharge tube after action is relatively low, and the residual voltage of the lightning protection unit can be prevented from being increased, so that the requirement on the protection performance of each power device in the power converter can be prevented from being increased.

The invention discloses a state evaluation system of a metal oxide resistor disc for a lightning arrester, relates to the technical field of electrical performance testing, and solves the technical problems that the specific influence degree of environmental factors on insulation resistance is difficult to accurately quantify, and meanwhile, the influence of various factors such as environmental conditions and operation conditions on the performance of the resistor disc cannot be comprehensively considered. By establishing a correlation model, combining the insulation resistance with environmental parameters, fully considering the influence of environmental factors on the insulation performance of the resistor disc, and by establishing the correlation model, the change rule of the insulation resistance can be analyzed more accurately, and reasonable performance change caused by external conditions is considered, so that the insulation performance of the resistor disc is improved. And the performance degradation of the resistor disc can be reflected more objectively in the subsequent comparison with actual detection data. Aging factors are calculated for each region, and the comprehensive health index of the resistor disc in each region is analyzed in combination with the relative deterioration degree coefficient of the insulation resistor, the relative deterioration degree coefficient of the resistive current and the dielectric loss coefficient.

This disclosure presents an embodiment of a power supply device for a submarine data center. One specific embodiment of the power supply device includes a pre-stage voltage regulator / conversion component, a post-stage DC-DC converter component, and a combined protection circuit. The pre-stage voltage regulator / conversion component includes several parallel single-group voltage regulator branches, each branch connected in series with a varistor and a color-coded resistor. A thin-film capacitor is connected in parallel to the output terminal of the pre-stage voltage regulator / conversion component. The post-stage DC-DC converter component, electrically connected to the pre-stage voltage regulator / conversion component, includes at least two sets of full-bridge DC synchronous rectifier circuits. The combined protection circuit includes a pre-stage combined protection circuit, a post-stage active voltage clamping circuit connected in parallel to the output side of the post-stage DC-DC converter component, and a rectifier diode bridge connected between the constant current input port and the pre-stage voltage regulator / conversion component. The pre-stage combined protection circuit is connected in series to the input side of the rectifier diode bridge. By connecting multiple voltage regulator branches in parallel and combining them with the combined protection circuit, ripple is reduced. This embodiment can improve the power supply stability of the power supply device.

The present invention relates to an apparatus for converting electrical energy to heat comprising a plurality of modules connected in series arranged between a first and a second de pole, wherein each of the modules has a controllable switchoff type semiconductor switching element. The invention is characterized in that the modules are varistor modules (VM) comprising a varistor (14) arranged in parallel to the switching element (12), and wherein the apparatus (10) further comprises a control system (CS) for controlling the energy conversion, wherein said control system (CS) is configured to actively control a current flowing through the apparatus (10) to equal a preset current reference value by selectively switching the switching elements (12). The present invention further relates to a converter arrangement with the apparatus and a method of operation of the apparatus.

The application discloses a voltage-limited overvoltage protection component with a recoverable electromagnetic drive tripping mechanism, which is composed of a voltage-limited overvoltage protector and an electromagnetic drive tripping mechanism. In a normal state, the normally closed contact of the electromagnetic drive tripping mechanism is in a closed state, which does not affect the normal working state of the voltage-limited overvoltage protector and the protection state under a normal intensity overvoltage. When an overvoltage occurs, a pulse current flowing through the voltage-limited pressure-sensitive resistor induces a current in the upper metal disc of the electromagnetic drive tripping mechanism, which is opposite to the direction of the spiral conductor coil of the lower electromagnetic drive disc, so that the upper metal disc of the lower electromagnetic drive mechanism induces an electromagnetic repulsive force with the lower electromagnetic drive disc, thereby causing the normally closed contact of the electromagnetic drive tripping mechanism to break, effectively inhibiting the continuous effect of a subsequent power frequency or direct current arc on the voltage-limited protector, prolonging the service life of the voltage-limited overvoltage protection component, and effectively realizing the safe use coefficient and prolonging the service life of the voltage-limited overvoltage protection component.

An anode potential adjustment device and an electron accelerator. The electron accelerator comprises a first electrode sheet (201), a second electrode sheet (202) and a high-voltage end (203), wherein the high-voltage end (203) is connected to the first electrode sheet (201). The anode potential adjustment device comprises a varistor (101) and an oil cylinder (102), wherein the varistor (101) is connected between the first electrode sheet (201) and the second electrode sheet (202); and the oil cylinder (102) is connected to a hydraulic pump by means of a hydraulic oil pipe, a piston of the oil cylinder is connected to the varistor (101), and the piston is configured to drive the varistor (101) to adjust a resistance value. The anode potential adjustment device can observe changes of a beam in real time when a high voltage and the beam exist at the same time, thereby making it easier to select an anode resistor (1010).

The invention discloses a surge protector, and relates to the technical field of overvoltage protection equipment, and the surge protector comprises a first separation unit and a second separation unit which are connected in series. The first separation unit comprises a first pole piece of the piezoresistor and an electrode piece electrically connected with the wire inlet end, and the first pole piece and the electrode piece are connected through soldering tin to form a first breakpoint. The second separating unit comprises a second pole piece of the piezoresistor, a moving contact electrically connected with the wire outlet end and a separating mechanism, the moving contact is in contact with the second pole piece to form a second breakpoint, the separating mechanism comprises a sliding block and an elastic piece, the electrode piece is fixed to the sliding block, and the sliding block is provided with a firing pin. When surge occurs in the circuit, the soldering tin is fused to disconnect the first breakpoint, the sliding block slides under the action of the elastic piece, and the firing pin pushes the moving contact to be separated from the second pole piece to achieve disconnection of the second breakpoint. According to the surge protector provided by the invention, the breaking capacity of the surge protector can be improved, and the risk of electrical accidents caused by untimely breaking is reduced.

The invention relates to the technical field of resistor life detection, in particular to a real-time life detection method and system for a piezoresistor. The method comprises the following steps: dividing a current impact experiment of the piezoresistor into a plurality of time windows, obtaining a plurality of related parameters representing that the resistance performance tends to be degraded in each time window, and screening out direct detection parameters measured by an instrument in a resistance degradation process; according to the relevance between the direct detection parameter and the indirect detection parameter of the multiple related parameters, obtaining the relevance significance and reference factors of the two types of detection parameters; weighting processing is carried out on the direct detection parameters to obtain variation characteristic quantities of the piezoresistor tending to deteriorate in different time windows, a prediction model is constructed through the variation characteristic quantities constructed in a self-adaptive weighting mode, and residual life detection is carried out on the target piezoresistor which is in a running state at present by utilizing the prediction model, so that the residual life of the target piezoresistor is detected. According to the scheme, the accuracy of predicting the real-time residual life of the piezoresistor in the using process is improved.

This invention provides a high-voltage suppression and voltage regulation protection circuit, relating to the field of circuit protection technology. The circuit includes a high-voltage discharge elimination circuit, a π-type composite EMI filter network circuit, and a voltage regulator circuit connected in sequence, with terminals at both the input and output ends. The high-voltage discharge elimination circuit consists of four DC spark discharge tubes and two varistors. The π-type composite EMI filter network circuit includes two high-voltage ceramic capacitors, two inductors, and one common-mode inductor. The voltage regulator circuit consists of an electrolytic capacitor and a Zener diode. Through the synergistic effect of the front-stage high-voltage elimination, intermediate-stage filtering, and rear-stage voltage regulation, the circuit achieves suppression and voltage regulation protection against high-voltage interference ranging from kilovolts to tens of kilovolts, ensuring continuous normal operation of the circuit system under harsh high-voltage environments.

The application discloses a graphene acceleration sensor with a ladder beam structure and belongs to the technical field of acceleration sensors. The graphene acceleration sensor comprises a support frame, a cross-shaped mass block, a substrate, ladder-shaped cantilever beams, graphene pressure-sensitive resistors, protective films, metal electrodes and metal pads. The cross-shaped mass block is located in the middle of the support frame, and each inner side wall of the support frame is connected with the cross-shaped mass block through a ladder-shaped cantilever beam. The substrate is bonded to the bottom of the support frame. Each ladder-shaped cantilever beam is a variable cross-section beam, which decreases from the cross-shaped mass block to the support frame. Each graphene pressure-sensitive resistor is arranged on each ladder-shaped cantilever beam, and each protective film covers the upper surface of each graphene pressure-sensitive resistor. The graphene acceleration sensor has a wide-range measurement range of 50000g, the sensitivity is improved by 36.11%, and the graphene acceleration sensor has excellent wide-range and high-sensitivity characteristics and significantly reduces the influence on the cross-axis sensitivity.

The invention belongs to the technical field of power electronics, and particularly relates to a solid-state direct-current circuit breaker module based on IGCTs, an upper pressing plate and a lower pressing plate are connected through a first screw rod, the number of first radiators is one more than that of the IGCTs, and the first radiators and the IGCTs are arranged in an overlapping mode; the number of the second radiators is one more than that of the first fast recovery diodes, and the second radiators and the first fast recovery diodes are arranged in an overlapping mode. First insulating cushion blocks are arranged between the first radiators and the lower pressing plate and between the second radiators and the lower pressing plate. Insulating cushion blocks II are arranged between the radiator I and the upper pressing plate as well as between the radiator II and the upper pressing plate and correspondingly abut against the radiator I and the radiator II through two force application mechanisms positioned on the inner side of the upper pressing plate; the piezoresistor is installed on the side, away from the first radiator, of the second radiator, the RCD protection unit is installed on the insulating plate, and the insulating plate is installed on the upper pressing plate and the lower pressing plate and located on one side of the first radiator and one side of the second radiator. The structure is compact, maintenance is easy, pressure is uniform, stray inductance is reduced, and overall stability and response speed are improved.

The application provides a method and device for improving the rated current breaking times of a direct-current solid-state circuit breaker and application thereof, and aims at the problem that the performance of an existing direct-current solid-state circuit breaker is degraded after multiple current impacts on a voltage-dependent resistor, the junction temperature of a power device is difficult to measure, and the breaking times are limited due to over-temperature damage, the application 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 accurately predicts 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 the turn-off overvoltage. The auxiliary energy absorption module is started when the junction temperature is close to the limit, and absorbs the remaining energy. The design reasonably allocates the turn-off energy, reduces the impact times and intensity of the voltage-dependent resistor, significantly improves the service life (such as about 10 times under the impact of 200 A), and further greatly improves the rated breaking times of the solid-state circuit breaker, and 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 MEMS (Micro Electro Mechanical System) sensors, and discloses a cap cilia MEMS vector hydrophone, which comprises cap cilia used for sensing sound to generate vibration for transmission; the center mass block is arranged at the bottom of the cap-shaped cilium, the cap-shaped cilium is located in the center of the top of the center mass block, and the center mass block is used for receiving vibration transmitted by the cap-shaped cilium and diffusing the vibration; the four cantilever beams are fixedly connected to the front face, the rear face, the left face and the right face of the center mass block respectively and used for receiving vibration transmitted by the center mass block and generating deformation. And the square frame is arranged outside the four cantilever beams. The cap-shaped cilia has a larger sound wave receiving area than the traditional cilia, the cap-shaped structure can generate larger on-beam stress on the cantilever beam when receiving sound pressure signals with the same size, so that the piezoresistor generates larger resistance change, the hydrophone is simple and mature in manufacturing process, the cap-shaped cilia does not need secondary integration, and the cost is low. And the consistency of the hydrophone is ensured.

A cooling system for a battery pack includes a plurality of thermal cooling channels, an inlet flow channel in fluid communication with each one of the plurality of thermal cooling channels, an exit flow channel in fluid communication with each one of the plurality of thermal cooling channels; and a varistor, in communication with a controller, positioned on one of the plurality of thermal cooling channels and adapted to generate a force change signal in response to pressure increase within a thermal cooling channel and to communicate the force change signal to the controller, the controller adapted to receive the force change signal, identify the occurrence of battery cell venting and a thermal propagation event based on the force change signal, and alter flow of coolant through the plurality of thermal cooling channels.

The application relates to the technical field of circuit protection, in particular to a transient overvoltage protection device with active isolation and reconstruction functions, and discloses a system named a transient overvoltage protection device with active isolation and reconstruction functions, which aims to solve the problems of single-point failure and protection interruption caused by performance degradation of metal oxide varistors. The device comprises a main / auxiliary discharge path, a state sensing module and a central cooperative controller; by monitoring the leakage current, temperature and clamping voltage in real time, the controller actively turns off the main path before the element deteriorates and switches to the standby path in milliseconds, so that the reconstruction is realized without disturbance. The scheme ensures that the protection function is continuously effective, and significantly improves the system resilience and power supply safety.

A core (C) of a surge arrester (SA), having an axial direction (L) and a radial direction (R) perpendicular to the axial direction (L), wherein the core (C) comprises: a first electrode block (100) and a second electrode block (200) located at two opposite ends of the core (C) along the axial direction (L), wherein the first electrode block (100) is provided with a plurality of first grooves (101) opening outwards along the radial direction (R), and the second electrode block (200) is provided with a plurality of second grooves (201) opening outwards along the radial direction (R); - a plurality of varistor blocks (301) sequentially arranged along the axial direction (L) and forming a varistor-block stack (300) pressed between the first electrode block (100) and the second electrode block (200); and - a plurality of insulating support members (400) sequentially arranged around the varistor-block stack (300), wherein a first end portion (401) of each of the insulating support members (400) is radially retained in the corresponding first groove (101) by a first blocking structure integrally formed on the first electrode block (100), and / or, a second end portion (402) of each of the insulating support members (400) is radially retained in the corresponding second groove (201) by a second blocking structure integrally formed on the second electrode block (200). Further, in the core (C) each of the insulating support members (400) has an annular configuration, such that the first end portion (401) and the second end portion (402) have a U shape, trapezoidal shape or triangular shape, and each of the first grooves (101) and each of the second grooves (201) have a corresponding U shape, trapezoidal shape or triangular shape.

The utility model discloses a safe type pressure sensitive resistance relates to resistance technical field, including the package shell, the package shell inside is provided with auxiliary mechanism, the auxiliary mechanism includes insulating foam layer, warning strip and elastic diaphragm, in the utility model, elastic diaphragm one side is fixedly connected with insulating foam layer, microswitch one side is fixedly connected with the package shell, and the elastic diaphragm is deformed after being extruded by grain boundary assembly expansion, and insulating foam layer exerts force on trigger strip after being stressed, triggers microswitch, and the circuit can be cut off by microswitch, and warning strip extends through -hole, and the mechanical early warning of aging sign is carried out, and it is convenient for staff to check in time, and the maintenance difficulty of reducing subsequently, and the one side of spacing piece is inserted with the support block, can be positioned to the installation of support block, and the installation and fixation of package shell bottom can be assisted by support block and fixed block, reduce the looseness after pin insertion, guarantee the stability when installing package shell.

The utility model discloses a high-efficiency low-cost high-voltage ignition detection circuit, which belongs to the technical field of high-voltage power supply electronics and comprises a high-voltage current detection resistor, a piezoresistor, a filter capacitor, a blocking capacitor, a first resistor, a second resistor, a third resistor, a fourth resistor, a fifth resistor, a first triode and a second triode. By means of the mode, faults such as electric field ignition and arcing can be found rapidly, meanwhile, the method is suitable for ignition detection of power supplies with different power sizes, positive and negative high-voltage power supplies can conduct effective ignition detection, and the anti-interference capacity is high.

The utility model discloses a surface mount type pressure sensitive resistance relates to resistance technical field, including resistance main part, the outside sleeve of resistance main part is connected with the packaging film, one side fixedly connected with the installation groove of packaging film, the inside fixedly bonded with the paste ring of installation groove, the other side fixedly bonded with the isolation ring of paste ring, the shape of paste ring and isolation ring is circular ring, the other side swing joint of packaging film has the pressing block. The utility model discloses through paste installation mode and installs pressure sensitive resistance, can significantly reduce the installation space occupancy, effectively reduces the risk of the physical interference with the surrounding components, guarantees the convenience of installation process and the connection reliability simultaneously.

The utility model relates to a multi-station detection device for constant-temperature and constant-humidity detection of a piezoresistor. The multi-station detection device comprises a first box body, a second box body and a detection box body, the first box body is located in the detection box body, and a plurality of connecting seats are arranged on the first box body; the second box body is located outside the detection box body, a connecting plate is installed in the second box body, a plurality of indicating assemblies are arranged on the connecting plate, each indicating assembly corresponds to one connecting base, each indicating assembly is electrically connected with one connecting base, and the indicating assemblies are used for sending out signals. The automatic detection device provided by the utility model has the effect of improving the detection efficiency.

The utility model discloses a testing device for a piezoresistor, which belongs to the technical field of resistance testing, and comprises a detection table and a direct current parameter tester, the top of the detection table is provided with a mounting groove, the interior of the mounting groove is provided with a conveying assembly, the conveying assembly is used for conveying the piezoresistor to be detected, and the direct current parameter tester is connected with the detection table. A fixing frame is fixedly connected to the top of the detection table, a test assembly is installed on the fixing frame, and the test assembly is used in cooperation with a direct-current parameter tester to test a piezoresistor to be detected. The piezoresistor testing device does not need to manually test the piezoresistor, is convenient and efficient in testing, is convenient for workers to quickly know the testing result, and is suitable for being popularized and applied by enterprises.

The application belongs to the technical field of micro electro mechanical system sensors, and discloses an acceleration sensor chip with a DLC optimized structure and a preparation method thereof; in the piezoresistive acceleration sensor chip, an SOI substrate is bonded to boron glass through a substrate frame, and a center mass is connected to the substrate frame through four embedded micro-beams arranged in a cross shape; four piezoresistance strips are arranged on the four embedded micro-beams, and the four piezoresistance strips are connected into a Wheatstone full bridge through surface metal leads deposited on the SOI substrate and connected with pads deposited on the SOI substrate; wherein, a DLC film is deposited on the SOI substrate, and the DLC film covers the surface metal leads, the four piezoresistance strips and the area of the SOI substrate except the pads. The application can improve the sensitivity of the sensor while ensuring the strength of the sensitive structure; the protection of the piezoresistance strips is realized, and the reliability of the sensor can be improved.

Disclosed in the present application are a varistor mounting structure and an electrical connection device, the electrical connection device comprising a power supply line (100) and a detection and protection apparatus provided on a circuit board and electrically connected to the power supply line (100). The detection and protection apparatus comprises a trip coil (Lx) for generating an electromagnetic force to disconnect an electrical connection, and a first varistor (ZR1) for absorbing a surge voltage. A support frame (400) for fixing the trip coil (Lx) is provided on the circuit board, and a first mounting portion (410) for mounting the first varistor (ZR1) is provided on the support frame (400). The first mounting portion (410) is provided with a first mounting hole (411) and a second mounting hole (412) for two pins of the first varistor (ZR1) to pass through respectively, and an isolation portion (413) for increasing a creepage distance is provided between the first mounting hole (411) and the second mounting hole (412).

This invention discloses a conductive paste for metallization of electronic ceramics, belonging to the field of electronic materials technology. The conductive paste for metallization of electronic ceramics of this invention includes copper alloy powder, glass powder, and an organic carrier. By controlling the ratio of copper, aluminum, and zinc in the copper alloy, the thermal expansion coefficient of the alloy is adjusted, making it compatible with electronic ceramic substrates such as alumina ceramics and zinc oxide varistors, achieving metallization through sintering under air conditions. The addition of tin improves the solderability of the metallized layer, meeting the process requirements of electronic components. The glass powder added in this invention has a low initial melting temperature, high bonding strength with the copper alloy, and strong adhesion to the ceramic substrate; combined with a specific ratio of organic carrier, it effectively improves the conductivity of the metallized layer after sintering.

Solid-state circuit breakers (SSCBs) have been witnessing an impressive progress with the aid of wide bandgap (WBG) devices such as silicon carbide (SiC) MOSFETs. Along with obtaining high efficiency as the result of low on-state resistance, response times have been gaining remarkable achievements in microseconds range. Not only that, the reported successes in control and gate drivers design and incorporating fault detection / location techniques in SSCBs are promising. A MOV-resistive capacitive switch (MOV-RCS) snubber for solid state circuit breakers addresses the following: 1) the MOV degradation issue in DCCBs is solved, 2) the maximum allowable DC bus voltage on DCCBs is extended. The solid state circuit breaker and an active clamping snubber includes a first circuit including a fault current bypass based solid state breaker for low voltage direct current systems.

The utility model relates to a lightning suppressor for lightning protection of an aircraft generator AC feeder. The lightning suppressor of the present disclosure comprises: a varistor; the first end of the voltage switch type surge protection device is connected to the first end of the piezoresistor, so that series connection of the voltage switch type surge protection device and the piezoresistor is formed; wherein the series connection of the piezoresistor and the voltage switch type surge protection device is connected between a generator AC feed line and the ground of the aircraft for lightning protection of the generator AC feed line.