216 results about "Electrical malfunction" patented technology

The invention relates to the technical field of electrical fault diagnosis, and discloses an electrical system fault diagnosis method based on multiple parameters. According to the method, multi-dimensional operation parameters of an electrical system are collected, wherein the multi-dimensional operation parameters comprise voltage waveform data, current waveform data and temperature distribution data; time-frequency conjoint analysis is carried out on the multi-dimensional operation parameters, and multi-scale electrical features are extracted and comprise steady-state feature components and transient feature components; based on a historical fault case library, performing mode matching on the multi-scale electrical characteristics to generate an initial fault type set; performing confidence evaluation on the fault types in the initial fault type set by using a dynamic weight distribution algorithm, and screening out high-confidence fault types; and according to the high-confidence fault type, a fault evolution path model is constructed, and the fault evolution path model is used for describing a time sequence of fault features.

The invention relates to the technical field of electrical fault positioning, in particular to an urban rail train relay state online monitoring method and system. The specific implementation process comprises the following steps: collecting coil current, contact voltage, load current and environment vibration signals by using an electrical sensor group; when the coil current is subjected to step change, intercepting an electromechanical characteristic data set; arc energy and contact resistance fluctuation characteristics are calculated, correlation analysis is carried out in combination with environment vibration signals, and passive fluctuation and active fluctuation are distinguished; and establishing a multi-factor health degree evaluation model, dynamically adjusting the arc energy and the weight coefficient of the contact resistance according to the magnitude of the load current and the vibration intensity, monitoring the health state of the relay in real time, and predicting the residual life. Through multi-dimensional data synchronous acquisition and vibration decoupling, the interference of mechanical vibration on electrical performance monitoring is effectively eliminated, the problem that a dynamic working condition cannot be reproduced in an off-line test is improved, and the accuracy of relay state evaluation and service life prediction is remarkably improved.

The invention relates to the technical field of intelligent circuit breakers, in particular to a holographic monitoring method based on a circuit breaker intelligent algorithm. The method comprises the steps of collecting operation data of a line where the circuit breaker is located; performing data preprocessing on the operation data; performing data processing on the preprocessed operation data to obtain monitoring parameters; holographic monitoring is carried out on an electrical fault according to the monitoring parameters; wherein when the operation data is preprocessed, a dual-frequency injection method is adopted to realize the separation of resistive residual current, a 2kHz high-frequency test signal is superposed on the basis of a fundamental wave frequency, and the resistive residual current is separated; meanwhile, an intelligent algorithm is adopted to carry out de-noising processing on the signal, that is, a dynamic threshold value is adopted to carry out wavelet de-noising processing, and an interlayer correlation coefficient is fused into wavelet threshold value calculation, so that self-adaptive protection of fault features is realized, and subsequent accurate power grid holographic monitoring is facilitated.

The embodiment of the invention provides an operation scene monitoring method and system based on panoramic stitching and holder linkage, and belongs to the technical field of video monitoring. The method comprises the following steps: respectively acquiring real-time panoramic video data and historical video data of an operation scene and a partial discharge signal of high-voltage electrical equipment; simulating electrical disease characteristics of the high-voltage electrical equipment based on the partial discharge signals and the environmental parameters of the real-time panoramic video data; obtaining work prediction information of the real-time panoramic video based on the historical video data and the electrical disease features; calculating deviation information of a real-time panoramic video according to the operation prediction information and the real-time panoramic video data; positioning a risk target area of the operation scene based on the deviation information, and determining a risk early warning signal of the operation scene for the deviation information based on a preset risk rule base; and issuing the risk early warning signal to a pan-tilt camera of the operation scene, and monitoring a close-up monitoring picture of the risk target area in real time. According to the invention, the risk handling efficiency of operation scene monitoring can be improved.

The invention relates to a cold chain equipment fault prediction and management method and system based on machine learning, and the method comprises the following steps: monitoring the operation parameters of cold chain equipment, capturing the parameter changes exceeding a preset threshold value in the operation parameters, and obtaining the parameter drift characteristics; based on the parameter drift feature, performing similarity mapping with a historical fault feature library to obtain a fault feature type; based on the fault feature type, in combination with the operation duration and recent maintenance records of the cold chain equipment, performing fault probability prediction on each component in the cold chain equipment to obtain a component fault probability table; according to a component fault probability table, performing grade division on the fault risk of each component in the cold chain equipment to obtain a component risk grade list; and generating an early warning management and maintenance scheme based on the component risk level list and the temperature control requirement of the cold chain equipment, thereby solving the technical problem that the change of the operation parameters cannot be effectively associated with the potential mechanical or electrical fault.

The invention discloses a fault diagnosis method and device for a permanent magnet motor system and a readable storage medium, and relates to the technical field of motor fault diagnosis, and the method comprises the steps: obtaining multi-mode data including current data, vibration data and thermal imaging image data, carrying out the preprocessing of each mode, obtaining the current, vibration and image data of a unified format, and carrying out the recognition of the current, vibration and image data; performing feature extraction and feature fusion on the preprocessed multi-modal data to obtain multi-modal fusion features representing the running state of the motor; and inputting the multi-modal fusion features into a pre-trained fault diagnosis model, and respectively outputting an electrical fault diagnosis result and a thermal fault diagnosis result of the permanent magnet motor system. According to the method, through multi-modal data joint modeling and fusion representation, the defect of limited single-modal diagnosis capability is overcome, and the precision and robustness of permanent magnet motor system fault diagnosis under complex working conditions are improved.

The present invention relates to a method of controlling an electrical protection device. When an electrical fault of the short-circuit type is detected during a step b) and when the tripping energy is greater than or equal to the tripping energy threshold in step d), controlling (S118) each switching module to enter the off-configuration. When the reclosing time of the given circuit breaker has elapsed, controlling (S122) each switching module to enter the on-configuration. If a circuit breaker is connected immediately upstream of the given circuit breaker, a test duration (T1) has not elapsed and a short-circuit is detected, performing steps c) to f) again; and if no circuit-breaker is connected immediately upstream of the given circuit-breaker, the test duration (T1) has not elapsed and a short-circuit is detected, controlling (S138) each switching module in the off-configuration.

The invention provides a high-voltage cable sheath grounding fault diagnosis method and device and electronic equipment, and relates to the technical field of electrical fault diagnosis and detection. The method comprises the following steps: acquiring a multi-source state parameter, wherein the multi-source state parameter is used for representing a real-time operation state of a sheath grounding system corresponding to a high-voltage cable sheath; performing multi-source heterogeneous data processing on the multi-source state parameter to obtain a fundamental component and a harmonic component of the sheath current and a vibration energy value of the cable joint; determining a current fault type based on the multi-source state parameter, the fundamental component, the harmonic component and the vibration energy value; determining fault section position information based on the multi-source state parameters and the electric power topological graph of the high-voltage cable sheath; and determining a fault diagnosis result based on the current fault type and the fault section position information. The fault diagnosis method and device are used for improving the comprehensiveness and accuracy of fault diagnosis, reducing the possibility of misjudgment and missed judgment, and being convenient for maintenance personnel to quickly position and solve the fault problem so as to guarantee stable operation of a power system.

According to the integrated thermal management method for the secondary circuit of the new energy automobile, mechanical abrasion or electrical faults are accurately recognized by monitoring the rotating speed and the current signal of the main water pump in real time, and the standby water pump is rapidly switched to guarantee circulation continuity of cooling liquid; meanwhile, the opening degree of the electric control valve is dynamically adjusted to optimize flow distribution of each branch, and the temperature of the battery is maintained in a safe interval in combination with multi-point temperature data fusion processing; in addition, by means of branch isolation and bypass channel switching, local faults can be handled in time, and the overall cooling capacity is maintained. According to the invention, the stability and safety of the thermal management system in multiple scenes are obviously improved.

This invention provides a bimetallic strip circuit disconnection control method and system, relating to the field of circuit protection technology. By acquiring the bimetallic strip deformation signal and calculating the difference, and combining different thresholds and durations for judgment, it distinguishes between instantaneous large fluctuations and continuous small faults, achieving accurate tripping and early warning. It has the advantages of effectively distinguishing between normal instantaneous fluctuations and continuous electrical faults, avoiding false tripping, and providing early warning, thereby improving the accuracy and reliability of circuit protection.

The invention relates to the field of cable wire barrows, in particular to a quick and convenient cable wire barrow which comprises a barrow body provided with a roller used for winding a cable. The cleaning mechanism is connected with the vehicle body and is used for cleaning the cable during paying off; the scraping mechanism is arranged at the end, away from the roller, of the cleaning mechanism and used for conducting secondary cleaning on the cleaned cable. According to the cable barrow, the problems that in existing cable pay-off operation, stains are prone to being attached to the surface of a cable, cleaning is difficult, and therefore insulation layer abrasion and electrical fault hidden danger are caused are solved, and the cable barrow is fast and convenient to use. According to the device, the cable is subjected to multi-stage cleaning treatment through linkage of the cleaning mechanism and the scraping mechanism, and the cleanliness and the insulation safety during cable laying are remarkably improved.

The utility model provides a kind of waterproof rubber parts of engineering truck wire harness connector, comprising: fixed wire harness part, spiral pipe diameter and connector protection part, the spiral pipe diameter is connected in one end of the fixed wire harness part, and the connector protection part is connected in one end of the spiral pipe diameter.The utility model provides a kind of waterproof rubber parts of engineering truck wire harness connector, using fixed wire harness part, spiral pipe diameter and connector protection part adopt ternary ethylene-propylene material, its stable molecular structure and smooth surface make water molecule difficult to invade and adhere, from material essence, guarantee waterproof effect, tightly adhere connector appearance design, effectively avoid water, greatly enhance the waterproof ability of connector and its to the matching end, reduce the electrical failure risk caused by water.

The utility model discloses a power distribution control device convenient to adjust, which comprises a cabinet body, a cabinet door mounted on the front side of the cabinet body through a hinge, a mounting rack arranged in the cabinet body, a sliding rail fixedly arranged on the front side of the mounting rack, a fixing hole formed in the front side of the sliding rail, a sliding sleeve slidably arranged on the surface of the sliding rail, and a mounting plate fixedly arranged on the front side of the sliding sleeve. Fixing assemblies are arranged on the front sides of the mounting plates, and a mounting back plate is connected between the opposite faces of the mounting plates. The limiting effect of the fixing assembly on the mounting plate and the sliding sleeve is relieved, and the mounting plate is driven to move through the fixing assembly, so that the mounting plate drives the sliding sleeve to slide on the surface of the sliding rail, the positions of the mounting back plates are adjusted, and the distance between the mounting back plates can be adjusted; the situation that the installation backboard is too troublesome to adjust due to bolt fixation is avoided, the wiring terminal of equipment can be located at a proper position, connection of wires is facilitated, bending and crossing of the wires are reduced, and the risk of electrical faults is reduced.

The utility model discloses a novel high-voltage auxiliary switch, which relates to the technical field of switches and comprises a shell, an upper cover, a push rod, a binding post, a reset spring, a static contact, a touch assembly, a pin shaft and the like. When the moving contact and the static contact are in a disconnected state, the switch can form a dual-port structure between the two static contacts. The unique design can effectively improve the power frequency withstand voltage value of the port between the two static contacts under the condition of a small structural volume. Compared with a traditional high-voltage auxiliary switch, the high-voltage auxiliary switch has the advantages that the risks of insulation breakdown and arc reignition are reduced due to the larger contact breaking distance, the stable and reliable electrical performance in a high-voltage environment is ensured, the safety and stability of equipment operation are greatly improved, and the conditions of equipment damage and production interruption caused by electrical faults are reduced.

The utility model discloses an intelligent controller for a commercial heat pump water heater, which comprises a controller main body, a display screen arranged at the front end of the controller main body, keys arranged at the front end of the controller main body, a limiting groove arranged inside the controller main body, a protective component arranged inside the limiting groove, a connecting wire inserted at the bottom of the controller main body, and a power supply connected with the connecting wire. A fixing assembly is arranged at the bottom of the controller body. By arranging the fixing assembly, the connecting line can be clamped and limited, the connecting line is effectively prevented from loosening or even falling off due to factors such as vibration and external force pulling in the using process, and therefore the stability of signal transmission is guaranteed, it is guaranteed that the water heater can normally operate, the probability of electrical faults is reduced, and potential safety hazards are reduced.

The application discloses a kind of laser measuring devices of pipe production, including shell, the inside middle part of the shell is equipped with driving swivel by bearing, the inside of the shell is provided with two symmetrical distribution laser seat.The application is driven by centrifugal force of cleaning mechanism, and the arc end tooth meshing structure of intermittent driving assembly is engaged, to realize the cleaning cycle of full mechanical linkage, the deflection contact of cleaning frame is directly driven by centrifugal force generated by rotation, the circumferential cleaning of autorotation ring is triggered by the meshing of movable gear and arc end tooth ring generated by the cooperation of starting wheel and starting arc frame, the reciprocating swing of jet pipe is realized by intermittent driving bevel gear on driving external gear ring, the power of all cleaning actions is obtained from the rotation movement itself of measurement scanning, without independent motor, cylinder or external control signal, compact structure, zero electrical failure risk, cleaning and measurement realize accurate timing cooperation and action partition in mechanical level.

The invention discloses a coal conveyor belt electrical fault early warning system and method based on the Internet of Things, and the method comprises the steps: obtaining operation state data and environment monitoring data, carrying out the preprocessing, analyzing an abnormal mode through a DBSCAN algorithm, generating a feature data set, building an early warning model based on an LSTM network, and carrying out the training, thereby obtaining an early warning result. And generating a maintenance and isolation instruction to regulate and control the equipment. The real-time performance and accuracy of electrical fault early warning can be effectively improved, the downtime of equipment is shortened, safe and stable operation of the coal conveying belt is guaranteed, and meanwhile the early warning comprehensiveness and reliability are improved in combination with multi-factor data.

The invention discloses a bus duct for high-voltage equipment connection and a high-voltage connection structure, and belongs to the technical field of high-voltage electrical equipment, and the bus duct comprises a housing which is internally provided with a channel penetrating through two ends, the channel is used for accommodating a bus bar, and the housing is an insulating material part; the multiple layers of bus bar groups are arranged in the channel at intervals in a layered mode, each layer of bus bar group comprises at least three bus bars, the at least three bus bars on the same layer are arranged at intervals, a gap is formed between the bus bar group and the inner wall of the shell, and the two ends of the bus bar group are located at the two ends of the shell respectively and used for being detachably connected with the high-voltage electrical equipment; the high-voltage connection structure comprises a bus duct, high-voltage power distribution equipment and a high-voltage transformer. Stable and reliable electrical connection is provided for high-voltage electrical equipment, it is ensured that the connecting position has high process quality, the heating phenomenon at the terminal head is effectively reduced, the occurrence rate of electrical faults is reduced, the technical requirement for operators is lowered, and meanwhile the construction cost is greatly saved.

The application discloses a plug-in and plug-out protective electric meter box and relates to the technical field of electric meter boxes. The plug-in and plug-out protective electric meter box comprises a mounting device. The electric meter cabinet is arranged between two sliding frames, and the bottom sliding frame is used for bearing the electric meter cabinet. The two sides of the electric meter cabinet are extruded by the clamping mechanism to achieve the clamping effect. The protection mechanism is connected with the clamping block to form a shielding effect on the surface of the cabinet body, thereby realizing the protection effect of the cabinet body. The electric meter cabinet is provided with a pneumatic device outside the electric meter cabinet. The pneumatic device is used for conveying air flow to the inside of the electric meter cabinet to achieve the ventilation and heat dissipation effect, reduce the temperature in the cabinet, guarantee the normal work of the components, reduce the condensation, prevent the electrical fault, balance the air pressure inside and outside the cabinet, avoid the structural deformation, avoid the damage of the cabinet structure caused by the air pressure difference, slow down the aging speed of the sealing element, and prolong the service life of the equipment.

This invention proposes a building electrical construction safety monitoring system and method based on Internet of Things (IoT) technology. Through image acquisition, modeling, data analysis, and calculation, it accurately identifies potential problems during construction, such as insufficient bending radius and space constraints. Compared to traditional manual inspection methods, this system can assess risks in real time and quantitatively, avoiding the oversights and delays of manual inspections. It can promptly identify potential cable bending risks during the construction phase, providing timely risk warnings to the construction team and helping them take appropriate adjustment measures to avoid serious electrical faults and fire hazards later. It enables optimization of pipeline layout and cable configuration in the early stages of construction, reducing electrical accidents caused by improper bending and ensuring the stability and safety of the building electrical system during long-term operation.

The utility model discloses a film laminating and pressing structure and a circuit board, and the film laminating and pressing structure comprises a substrate, the surface of which is provided with holes; the two stack-up structures are symmetrically arranged on the two sides of the substrate, and each stack-up structure comprises a barrier film, a three-in-one release film, a pressure buffering film and a heat conducting plate which are sequentially stacked on the substrate. According to the flexible-rigid combined board manufacturing method, by symmetrically arranging the stacked structures comprising the barrier films, the three-in-one release films, the pressure buffering films and the heat conduction plates on the two sides of the substrate, the common hole plugging problem during flexible-rigid combined board manufacturing in the traditional technology is solved, for example, the two release films are used as the barrier films and the pressure buffering films respectively, and the manufacturing cost is reduced. Wherein the barrier film is used for preventing a three-in-one release film material from being extruded into a hole in a substrate, and the pressure relieving film plays a role in relieving extrusion, so that the situation that an auxiliary material enters the hole due to uneven or overlarge pressure in the pressing process is effectively prevented, the cleanliness of the hole of the substrate is ensured, electrical faults possibly caused by the cleanliness are avoided, and the service life of the substrate is prolonged. And meanwhile, the appearance quality and the overall performance of the product are greatly improved.

The utility model relates to the technical field of electromechanical maintenance, in particular to a locomotive electrical fault diagnosis device which comprises a diagnosis box, a convenient holding assembly is installed in the center of the top of the diagnosis box, a rotary operation assembly is installed on the front side of the top of the diagnosis box, and the rotary operation assembly comprises a first containing groove and an auxiliary block. A fixing rod is fixedly connected to the top of an inner cavity of the first storage groove, the surface of the fixing rod is movably sleeved with a bearing block, a digital display controller is fixedly embedded in the front side of the bearing block, an insertion rod and a spring are installed on one side of an auxiliary block, and a groove is formed in the left side of the diagnosis box. Through the arrangement of the rotary operation assembly, the groove and the winding assembly, the test wire winding device has the advantage of being convenient to operate, a test wire can be wound on the movable rod, and the test wire can be pressed in cooperation with the blocking rod, so that the test wire is prevented from loosening and falling randomly, the placement stability of the test wire is guaranteed, and the test wire is convenient to take and use subsequently.

The application relates to the clothes processing technical field and discloses an elastic turning plate mechanism of an automatic clothes folding machine, which comprises a folding channel, a turning plate assembly and a transmission assembly. The turning plate assembly comprises two folding turning plates which are respectively arranged on the two sides of the folding channel and can be turned over to the inner side and the outer side of the folding channel. The transmission assembly comprises a transmission part which is connected to the two folding turning plates to make the two folding turning plates turn over synchronously. One folding turning plate is arranged on each side of the folding channel, the two folding turning plates are connected through the transmission part, and the two folding turning plates can turn over synchronously through the transmission part. When the folding turning plates are turned over to the inner side of the folding channel, the clothes in the folding channel are folded. In this way, the two folding turning plates are mechanically connected through the transmission part and can turn over synchronously, a plurality of electric telescopic rods are not needed to make the two folding turning plates turn over, and electrical faults are reduced to a certain extent.

The utility model relates to the technical field of cables, and discloses a graphene efficient heat dissipation cable which comprises a cable body, a conductor is arranged in the cable body, an insulating layer is arranged on the outer side of the conductor, a shielding layer is arranged on the outer side of the insulating layer, a heat dissipation layer is arranged on the outer side of the shielding layer, and an outer sheath is arranged on the outer side of the heat dissipation layer. The surface of the conductor is coated with a first graphene coating; and graphene microchips are uniformly dispersed in the insulating layer material. The cable has the following advantages and effects: through arrangement of the insulating layer, the heat dissipation layer and the outer sheath, heat generated in the cable can be rapidly conducted to the outer sheath through excellent heat conductivity of graphene, and then the heat is efficiently dissipated to the surrounding environment through the heat dissipation fins on the surface of the outer sheath; the purposes of effectively reducing the operating temperature of the cable, reducing insulation aging and electrical fault risks caused by overheating, greatly prolonging the service life of the cable and greatly improving the operating stability of the cable can be achieved.

The application discloses a kind of electric part quick disassembly type range hood, belong to domestic kitchen appliance technical field.The whole machine modularization is divided into wall fixed electrical part and quick detachable all-metal component assembly, motor and electric control module of electrical part are completely sealed and installed in electrical fixed mounting base, and oil fume isolation is realized by oil separation sealing ring;Upper box bottom plate is provided with matching positioning groove to ensure the coaxiality of motor and wind wheel, and tool-free quick disassembly is realized by hand screw bolt and fastening hand wheel.The application can realize the whole metal component to be taken down for deep cleaning, completely solve the pain points of traditional range hood cleaning difficulty, high electrical failure rate, assembly precision attenuation and resource waste, and the service life of electrical components is greatly extended, convenient to disassemble and assemble, suitable for domestic and commercial kitchen fume purification equipment.

The utility model provides an elevator slow descent device which comprises a base, a buffering assembly, a locking assembly, an elastic piece, a sealing cover and a speed sensor, a containing groove is formed in the base, the buffering assembly is rotatably arranged in the containing groove, the sealing cover is hinged to a groove opening of the containing groove, the sealing cover is used for sealing the containing groove, and the speed sensor is arranged in the containing groove. The speed sensor, the locking assembly and the elastic piece are all arranged on the base, so that the buffering device is contained in the containing groove under the condition that an elevator normally operates, the containing groove is sealed through the sealing cover, and the situation that the buffering device is corroded by dirt and water in an elevator shaft is effectively avoided; when the elevator falls at a high speed due to an electrical fault, and the speed sensor detects that the falling speed of the elevator reaches a threshold value, a signal indicating that the falling speed is too high is transmitted to the locking assembly, the buffering device is unlocked by the locking assembly, and the buffering device with the elastic piece is popped out to buffer the elevator.

This utility model discloses a rainproof power supply box for mountain disaster monitoring, comprising a main body, a sealing mechanism, and a ventilation mechanism. The sealing mechanism includes a connecting door, a mating door, a first spring, and a limiting frame. The ventilation mechanism includes a fan, a mounting bracket, a mounting frame, a filter pad, and auxiliary components. The auxiliary components include a ventilation component, an air outlet component, a second spring, rollers, and a locking block. With the cooperation of the above mechanisms, the pull-out door design of this device can ensure that the interior of the power supply box is completely sealed, preventing external rainwater, dust, mud, etc. from entering the equipment. In addition, this device can regularly replace the air inside the power supply box, which can effectively avoid the accumulation of humid gas and prevent mold, corrosion, or electrical failures caused by excessive moisture inside the equipment.

The invention relates to the technical field of new energy charging equipment, in particular to a new energy charging device with a protection device, which comprises a charging pile, a cable is fixedly arranged in the charging pile, a charging gun is fixedly arranged at the outer end of the cable, a waterproof mechanism is fixedly connected in the charging gun, and an air pump is fixedly arranged on the inner wall of the charging pile. A transmission ring is arranged on one side of the air pump, a transmission mechanism is rotationally connected to the transmission ring, and an anti-blocking mechanism is rotationally connected to the interior of the transmission ring. By arranging the waterproof mechanism in the charging gun, after the charging gun is pulled out, high-pressure air generated by the air pump can be sprayed out from all jacks of the charging gun through air spraying branch pipes on the waterproof mechanism; the high-pressure air can form an air curtain in the jack area of the charging gun, the possibility that rainwater directly enters the jack is reduced, electrical faults caused by water invasion are effectively prevented, the risk of electric shock or short circuit is remarkably reduced, and the safety of a user during charging operation is improved.

The system must be able to shut down safely even if an electrical malfunction occurs. [Solution] The liquid discharge head includes a drive means capable of performing at least one of a drive that circulates liquid and a drive that discharges liquid based on a printing signal, and a monitoring means that sets at least one of the drives that circulate liquid and the drive that discharges liquid as a target for monitoring, and monitors at least one of the signal supplied to the target for monitoring and the drive voltage supplied to the target for monitoring based on a predetermined set value, wherein the set value is set to be unrewritable.

The application relates to the technical field of POS machines, and provides a POS machine which comprises a face shell and a bottom shell connected together; a printer assembly and a control circuit board are arranged on the face shell; a first electric connection part is arranged on the printer assembly; a second electric connection part is arranged on the control circuit board and is spaced from the first electric connection part; a third electric connection part is arranged on the bottom shell; the bottom shell is connected with the face shell oppositely so that the third electric connection part is connected with the first electric connection part and the second electric connection part. When the POS machine is disassembled, the disassembling action of the face shell and the bottom shell can automatically remove the conduction state of the printer assembly and the control circuit board; the third electric connection part leaves the face shell with the bottom shell; an operator does not need to touch the first electric connection part, the second electric connection part and the third electric connection part; mechanical damage and electrical faults of the electric connection structure caused by disassembling operation are avoided; and the maintainability and reliability of the product are improved.