102results about How to "Reduce the risk of electric shock" patented technology

The present invention discloses a judgment method for a single phase power wiring, which solves the problems of reverse connection of the front line and the null line caused by a possible failure in single phase power supply. The safety performance of the circuit board is improved on the condition that the hardware cost is basically not increased. The specific technical proposal is that a front line terminal, a null line terminal, a ground wire terminal and a phase detecting circuit which is used for detecting the open-phase or anti-phase of a three-phase alternating-current supply are arranged on an outdoor unit main circuit board; wherein, the phase detecting circuit comprises two phase detecting branches. The input end of a first phase detecting branch is connected with the null line terminal through a wiring. The input end of a second phase detecting branch is connected with the ground wire terminal. Whether the front line and the null line are accurately connected is judged by detecting the state of the electric signal exported by the second phase detecting branch. In addition, the present invention also discloses a single phase power supply phase detecting circuit which is used for detecting and judging whether the front line and the null line are accurately connected during single phase power supply.

A device is described that can be easily used to accurately measure and monitor tissue thickness and structure using ultrasound. The device comprises a remote control and data processing unit, a handheld ultrasound transducer with an integrated position sensor.

The invention discloses a transformer substation comprehensive security platform applying an Internet of Things (IOT) technology, comprising a security management server, an office data center, a remote monitoring workstation, a transmitting antenna, an RFID (Radio Frequency Identification Devices) reader-writer, an exchanger, an instation monitor and interval radio-frequency gating terminals, wherein the office data center is downwards connected to the security management server and the remote monitoring workstation and is simultaneously connected to instation monitoring networks; the office data center is provided with at least two parallel instation monitoring networks; the instation monitoring networks are connected with a GPS (Global Positioning System) handset and the radio-frequency gating terminals arranged in the station at intervals in a wireless communication mode; according to the range of a specific task area, 1-n radio-frequency gating terminals can be arranged; and in the instation monitoring networks, the exchanger is upwards connected to the office data center and is simultaneously connected to the transmitting antenna, the RFID reader-writer and the instation monitor via connecting leads. The transformer substation comprehensive security platform has the advantages of simple integral structure, good stability and high relialibity, and is convenient to install, operate and use.

The invention discloses a multifunctional socket capable of adjusting spacings between adjacent jacks. The multifunctional socket comprises a socket panel; the left and right sides of the socket panel are connected with plug boards through a telescopic rod; a sliding rail is formed in the middle part of the upper surface of the socket panel, and the length of the sliding rail is longer than that of the socket panel; a groove matched with the sliding rail is formed in one side, close to the sliding rail, of each plug board; the part, exceeding the socket panel, of the sliding rail is clamped with the grooves; jack boxes are arranged at the top end of the first telescopic rod; jacks are formed in the middle part of the upper surface of each jack box; an electric wire is arranged at the right end of a wire hole; and a plug is arranged at the right end of the electric wire. The multifunctional socket capable of adjusting spacings between adjacent jacks is simple in structure, convenient to operate, and capable of lowering electric shock probability of a child through a protective cover and further improving the spacing between the adjacent jacks by virtue of sliding of the sliding block and up and down movement of the first telescopic rod, so that the usage rate of the jacks can be improved and use of multiple sockets can be reduced, thereby lowering cost, lowering difficulty in wire arrangement and improving attractive degree.

The invention provides a steel structure assembly device. The steel structure assembly device comprises an operating platform, an assembly device and hoisting rails; the assembly device is movably installed on the hoisting rails through rolling wheels; a lifting column is fixed to the bottom of an installing plate, and a piston rod of the lifting column is connected with an upper installing disk; the upper portion of a sliding rod is movably installed on a movable plate through a sliding hole formed in the installing plate; the lower portion of the sliding rod is fixedly connected with the upper installing disk; a limiting block is arranged on the top of the sliding rod; a connecting column is arranged at the bottom of the upper installing disk; a horizontal disk is arranged at the bottom of the connecting column and is provided with an annular slide rail; a rotating disk is of an annular structure and is movably installed on the annular slide rail of the horizontal disk through an annular groove in the bottom; an electric screw driver comprises a motor, a shell and a screw driver blade; the motor is connected with a power source through a controller; the screw driver blade is connected with a motor shaft of the motor through a speed reducing box which is arranged in the shell; the electric screw driver is installed on an installing hole of the rotating disk through the shell; and the operating platform is arranged below the assembly device.

An end cap (104) for a tubular light source (102), the tubular light source (102) configured to be arranged in a lighting fixture (106) comprising at least one socket (108), wherein the end cap (104) comprises, a first housing portion (202), two connector pins (208) at least partly arranged on an outside of the first housing portion (202) and adapted to fit in the socket (108), and a switch assembly comprising a switch element, wherein the switch assembly being adapted to form a conductive path between the socket (108) and the tubular light source (102) through a depression of the switch element in combination with a relative rotational motion of the first housing portion (202) in relation to the tubular light source (102) as the tubular light source (102) is mounted in the fixture (106).

The invention provides an electric field sensor dynamic test calibration device. The device comprises a shielding box; an electric field generation component which is fixed in the shielding box and used for generating an electric field; a movement control component which is fixed in the shielding box and realizes adjustment of the position and the attitude of an electric field sensor to be tested; a data acquisition component which is electrically connected with the movement control component and the electric field sensor to be tested and used for acquiring the data related to output of the electric field sensor to be tested and the movement attitude of the sensor to be tested; and an analysis control system which is electrically connected with the movement control component and the data acquisition component and used for processing and analyzing the position, attitude control and the data of the sensor to be tested. Automatic dynamic test calibration can be performed on one-dimensional, three-dimensional and micro structures of electric field sensors so that the electric field sensor dynamic test calibration device has the characteristics of being multifunctional, efficient and easy and convenient to operate and can better meet the application requirements.

A line lightning arrestor replacement device disclosed in the invention comprises a fixing plate, a mounting frame is fixedly connected on the left side of the fixing plate, a threaded cylinder is slidably connected between the top and the bottom of the inner wall of the fixing frame through a sliding block, one side of the threaded cylinder penetrates the fixing frame and extends to the outer side of the fixing frame, and the threaded cylinder is fixedly connected with the fixing frame on one side of the outer side of the fixing frame, and relates to the technical field of line lightning arrester. A lightning arrestor replace device for that line, The line arrester is secured by two clamps, so as to facilitate the installation and removal of the line arrester, Simple operation, and only one worker is required to complete the installation and removal of the line arrester, The device is fixed on the mounting tower by the first fixing part and the second fixing part so as to support theline arrester, so that the worker can free his hands and install the line arrester or remove and replace the line arrester.

Disclosed is a straight tube LED lamp provided with a straight tube containing a plurality of light emitting diodes on the inside, a first cap for feeding power to the light emitting diodes, provided on one end of the straight tube in the axial direction, and a second cap for grounding provided on the other end of the straight tube in the axial direction. A first terminal for electrical connection to a power feeding terminal of a first lamp socket is provided in the first cap. A second terminal for electrical connection to a grounding terminal of a second lamp socket is provided in the second cap.

The invention discloses an upward pulling type sunlight greenhouse safety roller shutter system. The upward pulling type sunlight greenhouse safety roller shutter system comprises an upper approach type switch module, a lower approach type switch module, a tubular motor, a travel switch, a rolling rope tension force detecting module, a reversing radar ranging module, a rolling shaft, a rolling rope, a sleeve, a support, a shaft support and a control module. According to the upward pulling type sunlight greenhouse safety roller shutter system disclosed by the invention, various working modes of the upward pulling type sunlight greenhouse safety roller shutter system are established, convenience is provided for an operator to control a heat preservation quilt, the labor is saved, the operation is humanized, the working modes are interactively used, the reliability of the upward pulling type sunlight greenhouse safety roller shutter system is ensured, the normal running of the upward pulling type sunlight greenhouse safety roller shutter system is fully ensured, and the production is orderly proceeded.

The invention discloses a battery car charging pile for outdoor use capable of conveniently being maintained in rainy days. The battery car charging pile includes a charging pile body, and one side ofthe charging pile body is rotatably connected with an service panel; a groove is formed in the service panel, and a first shielding plate is disposed on one side of the groove; a second shielding plate is disposed on one side of the first shielding plate, and first mounting holes are separately formed in the upper ends of the first shielding plate and the second shielding plate; and a support rodis disposed above the service panel, and the support rod is fixedly connected to the charging pile body. When the staff needs to inspect and repair the charging pile, by opening the service panel, the connecting rod is folded up to support the service panel, the service panel is fixed with a suction cup, and the first shielding plate and the second shielding plate inside the groove can be unscrewed from the groove through adjusting bolts, so that the rain shielding area of the service panel is increased, the maintenance of the charging pile in the rain and snow weathers is facilitated for thestaff, rainwater is prevented from entering the inside of the charging pile, the risk of electric shock to the staff is reduced, and the personal safety of the maintenance personnel is ensured.

The invention discloses an electric power overhaul construction safety management device, and belongs to the field of electric power construction engineering. The existing electric power overhaul construction safety management device has an unstable supporting structure, the overhaul safety performance is not high, and many electric power overhaul construction auxiliary devices cannot be conveniently telescoped and moved. The electric power overhaul construction safety management device disclosed by the invention is provided with a vehicle carrier and a driving control room, the overhaul construction management device can be conveniently moved, the electric power overhaul construction safety management device is provided with a telescopic driving device and a lifting device, thereby havingbetter stability than the traditional electric power overhaul construction auxiliary devices and improving the working efficiency of the electric power overhaul aloft work, the electric power overhaul construction safety management device is provided with an insulation climbing device, a lock catch and an elastic safety belt are arranged on an upper end of the insulation climbing device, so thata constructor wears elastic safety clothing during construction to prevent high-altitude falling, the electric power overhaul construction safety management device is provided with an insulation climbing rod to reduce the hidden danger of electric shock of the constructor during the construction, and the electric power overhaul construction safety management device disclosed by the invention has amore human-friendly design than the existing ordinary electric power overhaul construction auxiliary devices.

The invention discloses an anti-electric-shock socket, which comprises a protective shell and a socket body, wherein a through hole is formed in the upper surface of the protective shell, the inner wall of the through hole is movably connected with the surface of the socket body, the bottom part of the inner wall of the protective shell is respectively and fixedly connected with a first bracket and a fixed block, the fixed block is positioned at the back surface of the first bracket, the inner wall of a circular hole formed in the upper end of the first bracket is movably connected with the surface of a round rod, the socket body fixedly sleeves the round rod, a sliding groove is formed in the upper surface of the fixed block, the inner wall of the sliding groove is slidably connected witha push rod, the surface of the push rod is movably connected with the inner wall of a through hole formed in the left side of the protective shell, and the right end of the push rod is fixedly connected with a spring. Through setting the fixed block, the round rod, the sliding groove, the push rod, the spring, a tooth groove and a gear, the anti-electric-shock socket solves the problem of electric shock hazard since jacks of sockets on the market at present are exposed out of the surfaces of outer shells and the air humidity in the thunderstorm weather is large.

The invention relates to the field of electric car battery pack systems and discloses a power-off system for a battery pack of an electric car. The power-off system comprises a battery pack circuit combining device, a relay driving control circuit and a state detecting circuit; the battery pack circuit combining device comprises a battery pack positive and negative loop and a battery pack pre-charging loop, and relays are connected into the battery pack positive and negative loop and the battery pack pre-charging loop in series; the relay driving control circuit is electrically connected with the battery pack circuit combining device to control on-off of the relays in the battery pack circuit combining device; the state detecting circuit is electrically connected with the battery pack circuit combining device to detect the electric potentials of the connecting points of the battery pack circuit combining device as well as an electric car controller, a series connection battery set and a charging pile; and the relay driving control circuit and the state detecting circuit are connected with a battery management system. According to the power-off system for the battery pack of the electric car, the battery pack circuits are managed, and the working states of the circuits and the state of the series connection battery set are detected, so that isolation of high-low voltage signals is achieved, electric shock hazards and device damage are reduced, and circuit burnout in battery charging is avoided.

The invention discloses a leakage and overcurrent protection socket, which includes a leakage induction coil for sensing whether there is leakage of a single wire to the ground, and a tripping relay for controlling the on-off of the circuit. When the leakage of the single wire to the ground occurs, the circuit control system controls the The tripping relay is disconnected, cutting off the power supply. Real-time detection of the circuit by setting leakage induction coil, current mutual induction coil and voltage transformer to realize instant power-off protection. The risk of electric shock is reduced because the socket is disconnected when it is not normally used and the tripping relay is manually opened and then energized only during normal use. Eliminate the danger of leakage: When the human body touches the single live wire, it is necessary to manually open the tripping relay to get an electric shock, but the circuit control system will automatically cut off the power to prevent electric shock. Prevent fires caused by overcurrent. Energy saving and environmental protection, prolonging the service life of the circuit control system.

The invention provides a three-dimensional visualization system for a substation. The three-dimensional visualization system comprises automatic equipment, an intelligent control unit, physical isolation, a protocol conversion device, a video processing unit, an electric local area network, a data server and a user control terminal, wherein the automatic equipment is connected with the intelligent control unit; the intelligent control unit is connected with the protocol conversion device and the video processing unit through the physical isolation; the video processing unit is connected with the data server through the electric local area network; the user control terminal is connected with the data server by a browser or server technology; and the intelligent control unit is provided with an intelligent operation program, which is used for receiving an operation instruction and intelligently controlling the automatic equipment.

The invention provides a steel structure punching device which comprises a punching device body, a working platform, a top plate, upright columns and a sliding rail. The punching device body is movably fixed on the top plate through a mounting disk; punchers of the punching device body are movably mounted on a rotating disk; and the rotating disk rotates relative to the mounting disk. The working platform comprises fixed plates and movable plates, and the fixed plates and the movable plates are movably connected through upper sliding rods and lower sliding rods. The steel structure punching device has the advantages of good universality, less occupied space and the like.

The invention discloses a temperature and moisture preservation cabinet. An air inlet channel and an air outlet channel are formed in two sides of the cabinet body and communicated with the cabinet body, an upper air channel is respectively communicated with the air inlet channel and the air outlet channel, temperature and moisture sensors are arranged in the upper air channel, an air heating PTC (positive temperature coefficient) thermistor is arranged at an air outlet of a circulating fan, the top end of the air inlet channel is communicated with an air outlet of the circulating fan, a steam heating PTC thermistor and a box-shaped radiator contacting with the top of the steam heating PTC thermistor are arranged at an air inlet of the circulating fan, a water storage box is arranged at the bottom of the air outlet channel and communicated with the box-shaped radiator through a water pump and a water inlet pipe, and the temperature and moisture sensors, the air heating PTC thermistor, the steam heating PTC thermistor and the water pump are respectively connected with a control system. The temperature and moisture preservation cabinet solves the problem that an existing product cannot accurately control moisture, the temperature and the moisture can be respectively and independently controlled, a water tank is arranged at the inner bottom of the cabinet, water in the water tank can be effectively prevented from entering an electric box and causing dangerous accidents when in carrying and moving.

The invention discloses a food ingredient feeding machine which comprises a base, a support column, a charging trolley fork arm and a discharging hopper. The side wall of a turnover arm is connected with one end of a turnover pull rod through a hinge pin. The other end of the turnover pull rod is connected with a transverse column through a hinge pin, and the transverse column is fixed to the side wall of a supporting column. The side wall of the turnover arm is connected with the top end of an air cylinder through hinge pins. The bottom of the air cylinder penetrates through the base and is connected with a mounting block on the lower portion of the base through hinge pins. The lower portion of the air cylinder is sequentially connected with a first throttling valve and a hand-operated direction valve through a gas delivery pipe. The upper portion of the air cylinder is sequentially connected with a second throttling valve and the hand-operated direction valve through a gas delivery pipe. The hand-operated direction valve is connected with a gas pressure adjusting valve through a gas delivery pipe. The food ingredient feeding machine can replace manpower to pour out materials, so that the labor intensity of workers is relieved, the labor cost is reduced, and the work efficiency is improved; and besides, the food ingredient feeding machine can utilize a gas source as power, and the electric shock risk can be reduced in use.

The present invention relates to a wet type air washer, in which a water membrane of water, a salt solution, a basic solution, or an organic acid solution as a washing liquid is formed on a fine net and then the air contaminated with fine dust, ozone, mold, bacteria, harmful gas, and organic and inorganic materials is passed through the water membrane, thereby removing the contaminants through adhesion, adsorption, and dissolution of the contaminants with respect to the water membrane of the washing liquid, so that the wet type air washer increases the removal efficiency of the contaminants, is free from the controversy of harmfulness to human body by using a salt, a base, or an organic acid, which is a food additive, for antibacterial and bacteriostatic actions, and furthermore facilitates maintenance and internal washing.

The invention provides an LED fluorescent lamp and its module. The LED fluorescent lamp includes a lamp tube, a first end cover and a second end cover installed at both ends of the lamp tube, and the lamp tube includes a lamp board, a plurality of LEDs and a light emitting cover , the first end cap is a conductive end, the second end cap is a sealed end, and the positive and negative conductive ends of the lamp board are only led out from the first end cap. The module is provided with a fixing device, which is a lamp tube fixed socket with single-end power supply matching the LED fluorescent lamp, and the first end cover of the LED fluorescent lamp is directly inserted into the lamp tube fixed socket to be electrically connected to an external power supply. The LED fluorescent lamp of the present invention is truly single-ended conduction, so it can completely eliminate the hidden danger of electric shock during installation, has low design cost, low energy consumption, simple installation and operation, and helps to promote the wide-scale popularization of LED fluorescent tubes.

The invention relates to the technical field of 5G communication application. The invention further discloses a device capable of automatically powering on and powering off the electric appliance socket based on 5G communication. The device comprises a partition plate and a shell, a baffle is fixedly connected to the bottom of the partition plate, a communication chip is fixedly connected to the exterior of the baffle, a first spring is fixedly connected to the exterior of the baffle, an inserting groove is fixedly connected to the end, away from the baffle, of the first spring, and a second spring is movably connected into the inserting groove; under the interaction among the partition plate, the baffle plate, the communication chip, the first spring, the slot, the second spring, the pressing block, a stopper and a plug, a user can remotely control the combination of the plug and the slot through the remote control terminal under the action of 5G communication; a prerequisite condition is provided for connecting the plug with a power supply later, electric power is prevented from being wasted to a greater extent, the plug can be fixed by the structure in the slot and the adsorption disc, the possibility that a traditional plug is easy to loosen is avoided, and the plug is more suitable for a user to use.

The invention discloses an electric shock-proof fire hydrant, which comprises a fire hydrant box, a hose reel, a fire hose with a conductive braided layer of the hose and a hose spray gun, and a fire hydrant box. The bottom of the body is provided with a fire-fighting water supply pipe column connected to the underground tap water, and a hose joint that is clamped to the end of the fire-fighting hose is provided on the fire-fighting water supply pipe column, and a hose joint switch valve is provided at the upper end of the water hose joint; the fire-fighting water supply The side end of the pipe column is connected with a fire branch pipe, and a water inlet elbow is installed in the hose reel, the water inlet end of the water inlet elbow is connected with the fire branch pipe through a pipe, and the outlet end of the water inlet elbow is sealed with Rotate the water outlet casing, and the hose reel is fixed with a brush assembly that slides and fits with the outer wall of the rotating water outlet casing; the structure design of the invention is reasonable, and the current can be quickly transmitted to the ground, reducing the early stage of fire fighting and saving fire extinguishing preparations time, to ensure the effectiveness of fire fighting and the safety of the firefighters themselves.

The invention relates to a segmented lamp comprising a plurality of connection devices, wherein lighting units are arranged between adjacent connection devices; each lighting unit comprises a lamp holder; a light source module is arranged in each lamp holder; rotary connection parts extending into the connection devices are respectively arranged on two sides of each lamp holder; and the rotary connection parts are clamped by the connection devices without falling off and can rotate relative to the connection devices. By means of the combination design of the segmented lamp, a user can make changes according to different landform restrictions and requirements; the setting process can be simplified and the practicability can be promoted; and the power lines of the light source modules are not exposed by means of the connection combination design so that solarization and embrittlement of the power lines are avoided and the using safety is enahnced.

The invention provides a personal safety auxiliary protection device for electric power construction. The personal safety auxiliary protection device comprises a standing seat, a fixed belt seat, a main seat fixed belt, a double-round groove, a wire hook, a net rod threaded seat, a conductive needle, a spring, a clamping plate, a pull wire, a pedal plate, an insulating plate, a magnet plate, a front shoe fixing belt, a leg fixing belt, a net rod buckle, an electric wire frame, a protective net, a net edge fixing buckle and a fixed buckling belt, wherein a T-shaped groove is formed in the bottom of the standing seat; a bracket sliding block is integrally arranged at the top of a main seat bracket, and the main seat bracket is movably arranged in the T-shaped groove in the bottom of the standing seat through the bracket sliding block; a screw hole is formed in the middle of the top of the main seat bracket, and a fixed bolt is movably arranged in the screw hole; and a threaded structureis arranged at the bottom of a telescopic net rod, and the telescopic net rod is fixedly arranged in the net rod threaded seat through the threaded structure; by arranging the main seat fixing belt, the standing seat can be fixed to the outer end of a telegraph pole, so that the stability is enhanced.

The invention discloses an ESO-based pure electric vehicle bus capacitor discharging system and method. The system mainly comprises a controller, a power battery, a circuit breaker, a DC / DC converter, a bus capacitor, an inverter and a three-phase permanent magnet synchronous motor. According to the method, a permanent magnet synchronous motor winding is used as an energy bleeder. According to the method, a discharge process is divided into three stages: firstly, a fixed current is applied to a d axis in a weak magnetic voltage reduction stage, so that a bus voltage is rapidly reduced to a safe voltage, and the system enters a constant voltage stage; in the constant-voltage stage, ESO is adopted to observe the total loss in the system discharge stage, feedforward compensation is carried out, the bus voltage is stabilized at the safe voltage, and when the rotating speed is reduced to be lower than the safe rotating speed, the free deceleration stage is started, and d-axis and q-axis currents are gradually reduced to 0; through the above three stages, safe and rapid discharge of the bus capacitor of a pure electric vehicle driving system in emergency is realized, the surge phenomenon of the bus voltage is avoided, and the method has the advantages of high robustness and high safety.

The invention provides a Hall current detection device, comprising a current-carrying conductor, an insulated shell structure, a detection assembly and a connecting shell, wherein the insulated shell structure is directly or indirectly fixedly connected with the current-carrying conductor; the detection assembly is used for detecting current flowing through the current-carrying conductor, and comprises a Hall element close to the current-carrying conductor, a circuit board electrically connected with the Hall element and an output lead electrically connected with the circuit board; and the connecting shell is an insulated shell, fixedly connected with the Hall element, and detachably fixedly mounted with the insulated shell structure. The technical problem to be solved by the invention is to overcome the defects that the Hall current detection device in the prior art, which needs to be disassembled and assembled in a power-off manner, lowers the production efficiency, affects the production and has low safety, thus providing a Hall current detection device which is disassembled and assembled with power, does not lower the production efficiency, does not affect the production and has high safety.

The invention relates to a pressing self-outage socket. A pressing type flexible switch is arranged in a socket body; a socket is arranged on the flexible switch; the socket springs up at ordinary times and no power is supplied in the socket; the socket is wholly pressed and then is powered-on after a plug is inserted into the jacks of the socket; after the socket is pressed for one time, the socket and the pressing type flexible switch are descended and are powered-on; after the socket is pressed again, the socket and the pressing type flexible switch are ascended and are powered-off. The pressing self-outage socket is a device with a springing pressing type flexible switch arranged in a conventional multipurpose socket, so that the electric shock caused by the children by inserting foreign matters or fingers into the jacks can be effectively prevented and the electric shock risk can be greatly reduced. Besides, the pressing self-outage socket can meet the individualized recharging requirement of the frequently recharged home appliances, such as, mobile phones; a plurality of rechargers can be simultaneously inserted into the safe socket; the socket can be pressed for recharging when a recharger needs to be recharged; after the recharging is ended, the socket can be pressed again so as to spring up and cut off the power; the rechargers need not be pulled out and then plugged in, so that the socket is convenient and practical.

The invention discloses a superaudio heater and relates to the technical field of metal heating. The superaudio heater is characterized in that an ultrasonic fault detector is arranged before a blankenters a superaudio heating coil, the blank is subjected to fault detection before the big blank is heated by the coil, explosion of the blank with cracks in the internal structure is prevented, and operator safety can be maximumly guaranteed. The superaudio heater is provided with a PLC (programmable logic controller), a servo motor, a Naki insulated soft felt conveyor belt and a vacuum insulation panel, the outer surface of the blank can be heated uniformly, and heating rate is adjustable; a split design is adopted on the superaudio heater, a main cabinet and a sub cabinet are connected witha cable, the main cabinet is placed at the place outside a workshop or an operation room, the sub cabinet is placed in the workshop or the operation room, an operator can only access the sub cabinet,voltage released by the sub cabinet is below 36V, and electric shock hazard of staff can be minimized.