126results about How to "Reduce work loss" patented technology

The invention relates to a dismountable locking mechanism of a drawer slide rail and a side plate. The dismountable locking mechanism comprises a side plate, a bottom plate and a slide rail assembly used for opening and closing a drawer, wherein a front connecting element for connecting a front panel and a back connecting element for connecting a rear back plate are arranged on the side plate, a groove position for accommodating the bottom plate is arranged in the side plate, the bottom plate is arranged on the groove position and acts on a movable slide rail of the slide rail assembly, a dismountable locking mechanism is arranged between the side plate and the movable side rail, and the movable side rail is detachably connected with the side plate through the locking mechanism. The dismountable locking mechanism has the advantages that the groove position used for fixing the bottom plate is arranged in the side plate, the bottom plate directly acts on the movable slide rail after the assembly is completed, the drawer stress is more uniform, the work loss of each component is smaller, the service life is longer, the inner wall of the side plate is vertical, the thickness of the side plate is effectively reduced, the use space of the drawer is increased, in addition, the side plate and the movable side rail are detachably connected through the dismountable locking mechanism, the dismounting and the mounting of the side plate and the movable slide rail are fast and convenient, the manufacture and maintenance cost is low, the integral design of the drawer is favorably realized, and the drawer is tidier and more attractive.

The invention provides an uninterruptible power supplying method and an uninterruptible power supply. The method comprises the steps as follows: switching the uninterruptible power supply from a main loop working mode to a bypass working mode so as to enable commercial power to be supplied to a load through a bypass; determining the working mode of the uninterruptible power supply; adjusting the working frequency of at least one switch tube in the main loop of the uninterruptible power supply from a first frequency to a second frequency, wherein the second frequency is smaller than the first frequency so as to lower power loss of the uninterruptible power supply under the bypass working mode. According to the embodiment of the invention, when the uninterruptible power supply is switched to the bypass for running, the working frequency of the switch tube of the main loop of the uninterruptible power supply is lowered. Therefore, the work loss of the uninterruptible power supply can be lowered, and the work efficiency of the uninterruptible power supply can be effectively improved.

The invention provides a shifting register and an array substrate grid drive device. The shifting register is of a structure for multi-stage connection of the same shifting register units, wherein each shifting register unit comprises an input module responding to an input signal, an output module responding to an upward pull node, a reset module responding to a reset signal, a first upward pull module responding to a first clock signal, a second upward pull module responding to a downward pull node voltage signal, a first downward pull module responding to a first upward pull node voltage signal, a second downward pull module responding to an upward pull node voltage signal, a control module responding to a second clock signal and a retaining module responding to the first clock signal and a second downward pull node. The working loss of the shifting register can be reduced, attenuation of a second downward pull voltage signal is reduced, and accordingly the stability of the shifting register in working is improved.

The invention relates to a bistable micro-electromechanical relay, in particular to a micro miniature relay with state maintaining function, which is mainly applied to systems of power supply management, instruments and meters, automatic control and wide band communication, etc. The relay comprises a packaging cover, a base pin, a movable diaphragm, micro balloons and an electromagnetic base plate; wherein, the movable diaphragm and the micro balloons are positioned in a hollow cavity formed after the packaging cover, and the electromagnetic base plate are fixedly connected, upper electrodes opposite to the lower electrodes at the left end and the right end of the upper surface of the electromagnetic base plate are respectively arranged at the two ends of the movable diaphragm, round holes are distributed along the longitudinal symmetric axis of the movable diaphragm, and are movably positioned on the corresponding micro balloons, and the microballoons are movably positioned on the round holes of a microballoon base seat on the electromagnetic base plate. The integration level of the relay is high, bistable electromagnetic driving and state locking are realized, the driving energy consumption and the working loss are reduced while the response speed and the service life of the relay are obviously improved, the response time is short, the insulating strength and the compression strength are high, and the work is stable.

The invention relates to a fingerprint detecting technology, and discloses a device and a method for detecting a living body fingerprint. The device for detecting the living body fingerprint comprises a fingerprint detecting unit, a living body detecting unit and a verifying unit, wherein the fingerprint detecting unit is used for detecting fingerprint information of a detected body; the living body detecting unit is used for detecting living body characteristic information of the detected body, and the living body characteristic information is unique living body information of the detected body; the verifying unit is used for comparing the detected characteristic information of the detected body with registration , which is registered in advance, information of the detected body, the verifying can be passed if the characteristic information is consistent with the registration information, and the characteristic information comprises the fingerprint information and the living body characteristic information. According to the device and the method for detecting the living body fingerprint, disclosed by the invention, compared with the prior art, as the living body fingerprint detecting device simultaneously comprises the fingerprint detecting unit and the living body detecting unit, and the unique living body characteristic information of the detected body is detected while the fingerprint information is detected, the authentication carried out through fingerprint detection can be safer and more reliable.

The invention discloses a fast recovery diode and a manufacturing method of the fast recovery diode. The diode disclosed by the invention comprises an anodic diffusion P-type doped region, an evenly-doped intrinsic region, a cathodic diffusion N-type region, anode and cathode metal layers, wherein the anodic diffusion P-type doped region is a P-type doped region provided with alternated high and low concentrations and formed by locally pouring through a mask plate. Compared with the prior art, the diode disclosed by the invention has the characteristics of low inverse peak current IRRM, short reverse recovery time trr and high reverse recovery softness.

The invention relates to a pumping aid in pumping delivery of lightweight aggregate concrete. A lightweight concrete pumping aid is characterized by having a homogeneous mixture made of cellulose ether, polyethylene oxide, methyl cellulose, sodium dodecyl sulfate and siliceous dust, wherein the formulated rate is arranged by weight as: 8-12 portions of cellulose ether, 1-5 portions of polyethylene oxide, 30-300 portions of methyl cellulose, 5-15 portions of sodium dodecyl sulfate and 100-300 portions of siliceous dust. The pumping aid is used for delivery of lightweight aggregate concrete, which can dramatically improve the homogeneousness of lightweight aggregate concrete, reduce the gradual loss in slump of lightweight aggregate concrete, reduce the performance loss in the process of pumping up lightweight aggregate concrete and improve pumping capacity of lightweight aggregate concrete, thereby having a tremendous market potential in the construction of large-span bridges, high-rise buildings and special structures.

A slip sheet removing device (14) comprises an arm (42), a head (44) engaged with the distal end of the arm (42), and a mechanism (46) for moving the arm (42) in the direction where the head (44) approaches a planar body or the direction where the head (44) recedes from the planar body. The head (44) has a head body (54) and at least one mechanism (56) for nipping a slip sheet. The moving mechanism (46) moves the arm (42) in the direction where the head (44) approaches the planar body, the nipping mechanism (56) nips the slip sheet on the topmost surface, the moving mechanism (46) moves the arm (42) in the direction where the head (44) recedes from the planar body, then the nipping mechanism (56) releases the nipped slip sheet and removes the slip sheet from the planar body.

The invention discloses a DC (Direct Current)-AC (Alternating Current) transfer circuit and a control method thereof. The DC-AC circuit comprises a boost inducer, a boost switch tube, a rectifier diode, from first to fourth capacitors, an inverter bridge FWD (Fly-Wheel Diode), and from first to second output filter inducers. The invention further discloses a control method of the AC-DC transfer circuit. By using the different inversion working models of the boost circuit and the inverter bridge circuit, the invertion can be maximally performed by using the voltage of the DC input source, the working current of the boost circuit and the switching stress of all elements in an inverter bridge loop can be reduced, the working loss of the main elements of the boost circuit can be reduced, and the switching loss of all elements in the inverter bridge loop can be reduced, so that the efficiency and power density can be improved.

The invention discloses an efficient bicycle gear, which comprises a converter arranged on a bicycle frame. The transmission shaft of the converter extends out from the two ends and is respectively provided with a left pedal rod and a right pedal rod on the two ends, the extension end of the transmission shaft of the converter is also provided with a drive gear, and the drive gear is engaged with a driven gear arranged on the end of a drive sprocket shaft. In the structure of the converter, a left shaft sleeve and a right shaft sleeve are respectively supported on the two sides of the transmission shaft through a first bearing and a second bearing, wherein the left pedal rod is fixed on the left shaft sleeve, the right pedal rod is fixed on the right shaft sleeve, and the left pedal rod and the right pedal rod are arranged to be staggered for a certain angle; the outer edges of the left shaft sleeve and the right shaft sleeve are respectively supported in a shell through a third bearing and a fourth bearing; and the opposite sides of the left shaft sleeve and the right shaft sleeve are respectively provided with a one-way transmission clutch, the driving links of the one-way transmission clutches are respectively connected with a driving bevel gear, and the two driving bevel gears are both engaged with one driven bevel gear.

A power supply device for a computer device mainly comprises a DC to DC converter used to receive and convert an outside DC power supply to a variety of DC voltages needed for a computer device and an up / down regulator connected to the DC to DC converter and used to stabilize an output voltage. According to the present invention, the up / down regulator is installed before the +12 voltage input end of the computer device. Whereby, the +12 voltage can be stabilized and the work loss of the power supply for the computer can be lowered down.

The invention discloses a single-effect external circulation concentrator based on a condensation bead collection mechanism, and relates to the technical field of concentrators, the single-effect external circulation concentrator comprises a heating tank, a cooling mechanism, a liquid separation mechanism and a wall scraping mechanism; the top end of the heating tank is provided with a feed inlet,and one end of the outer wall of the heating tank is provided with a steam inlet pipe and a condensate outlet pipe; the end, away from the heating tank, of the steam inlet pipe is connected with an air heater. By arranging the rotating shaft, the connecting rod, the scraper, the connecting bearing, the fixing rod, the fan blades, the motor, the water inlet pipe and the water inlet valve, wall scraping operation can be conducted on the interior of the evaporation chamber, the fan blades are driven to rotate through steam flowing, and the fan blades can drive the scraper to conduct wall scraping operation on the inner wall of the evaporation chamber through the rotating shaft and the connecting rod, thereby aoviding adhesion of the material liquid to the inner wall of the evaporation chamber; in addition, cleaning water can be injected into the evaporation chamber through the water inlet pipe to be cleaned and maintained, the fan blades and the scraper are driven by the motor to rotate,the cleaning water can be stirred, and the evaporation chamber can be better cleaned.

The invention discloses an elevator compensation chain guiding control device, and belongs to the field of compensation chain guiding devices. According to the elevator compensation chain guiding control device, in the scheme, a pair of guiding rollers can restrain a compensation chain, overall shaking of the compensation chain is reduced, the surface of a roller body is treated, the the elasticity of the surface of the roller body is increased through laid filling balls, so that abrasion between the compensation chain and the roller body is reduced. For the filling balls located in a filling groove, the multiple filling balls can be kept in a tiled state in the filling groove through matching of filling fibers between the adjacent filling balls and connection between the filling fibers and a reinforcing net, a relatively stable structure of the multiple filling balls can be easily kept, the loss of the elevator compensation chain in the using process can be greatly reduced, the instability phenomenon in the using process of an elevator is not likely to occur, the working loss of the elevator is reduced, the service life of the elevator is not likely to be affected, and casualties of passengers are not likely to be caused.

The invention discloses a circuit topological structure of a low-voltage input isolation type multi-circuit output switching power supply. The circuit topological structure comprises a voltage boosting circuit, a power conversion circuit and a rectifying circuit, wherein the voltage boosting circuit is connected with the power conversion circuit; and the power conversion circuit is connected with the rectifying circuit. By virtue of the circuit topological structure, multi-circuit isolation voltage output in a low-voltage input condition is realized, and the product assembling density and the production cost are lowered.

The invention discloses a displacement amplification ultrasonic linear motor which mainly comprises a motor stator with a centre hole and a motor rotor penetrating in the center hole, wherein the motor stator mainly comprises a stator shell as well as a radial groove and an axial groove which are arranged on the stator shell; the radial groove and the axial groove are radially arranged and axially arranged along the center hole respectively; one end of the radial groove is communicated with the center hole; the left side or right side of the radial groove is provided with a spring groove communicated with the radial groove; the axial groove is positioned on the right side or left side of the radial groove and communicated with the radial groove; a radial piezoelectric strip is arranged inthe radial groove; an axial piezoelectric strip is arranged in the axial groove; and a spring is arranged in the spring groove. The invention also discloses a working method of the displacement amplification ultrasonic linear motor. The displacement amplification ultrasonic linear motor disclosed by the invention has the advantages of large thrust, high efficiency, low loss, high speed and long service life.

The invention discloses a solar thermal collector. The solar thermal collector comprises a thermal collection tube set, a reflection plate and a controller. The thermal collection tube set comprises a plurality of thermal collection tubes arranged side by side. The reflection plate is formed by splicing a plurality of base blocks and connecting plates in sequence, wherein the base blocks are arranged side by side. The upper surface of each base block is concave downwards to form an arc-shaped groove for containing the corresponding thermal collection tube. An arc-shaped reflection substrate is embedded in each arc-shaped groove. A through arc-shaped channel is formed in each base block and located below the corresponding arc-shaped groove. The upper surface and the lower surface of each arc-shaped channel are in sliding connection with a first arc-shaped sliding plate and a second arc-shaped sliding plate respectively in the arc direction. The controller is arranged to control the first arc-shaped sliding plates and the second arc-shaped sliding plates to slide in the arc-shaped channels. The solar thermal collector is simple in structure, convenient to use and practical. When water heating is not needed, the thermal collection tubes and the reflection substrates are covered, and meanwhile solar energy is converted into electric energy for storage and use, so that the economical use value of the solar thermal collector is increased, and the service life is prolonged.

The invention discloses a double-split-flow turbine steam-inlet diversion structure. The double-split-flow turbine steam-inlet diversion structure comprises a runoff type first-level stator and a wheel type rotor which are correspondingly assembled together. The two sides of the portions, corresponding to the first-level stator, of the wheel type rotor are correspondingly provided with impellers protruding in the radial direction and being used for assembling movable blades. Diversion mold cavities are defined by the first-level static blade, the wheel type rotor and the corresponding movableblades. The movable blade root positions of the two sides of each diversion mold cavity are correspondingly provided with streamline sharply protruding steam inlet diversion portions extending to thediversion mold cavity. The steam inlet diversion portions of the two sides of each diversion mold cavity are oppositely formed. The steam inlet diversion portion on each side and the blade root steaminlet side face and the blade root plane of the corresponding movable blade are in smooth transition in the form of the streamline profile structure. By the adoption of the double-split-flow turbine steam-inlet diversion structure, the stability and reliability of bidirectional conversion from runoff steam to axial flow can be guaranteed effectively; and meanwhile flow separation generated beforethe diverted steam enters the movable blades can be effectively prevented, the uniformization of the steam flow entering the corresponding movable blades is guaranteed, and the acting loss of the movable blades is lowered.

The invention discloses a double-valve-core programmable-control hydraulic valve adopting digital fluid pilot drive and a control method thereof. The hydraulic valve comprises a main valve body, eighthigh-speed switch valves, four one-way throttle valves and two three-position two-way proportional valves, wherein the two three-position three-way proportional valves are positioned in the main valve body; the right high-speed switch valves are mounted on the main valve body; and a main oil path PTAB port, a pilot oil path P port and a pilot oil path T port are arranged on the main valve body. The double-valve-core programmable-control hydraulic valve adopts valve cores of a pilot-level control proportional valve consisting of the high-speed switch valves, and has the advantages that: whilethe positions of the valve cores of the proportional valves are regulated, oil pressure disturbance at the two ends of each proportional valve can be greatly reduced, and stability while the proportional valves work is improved; and while the positions of the valve cores of the proportional valves are kept, oil pressure disturbance at the two ends of each proportional valve can be completely eliminated, and all high-speed switch valves on the oil path are in a normally open state, so that work loss of the high-speed switch valves is reduced, and the working service life of the oil path is prolonged.

The invention provides a method and device for data storage. The method and device are applied to the situation that a power failure happens when measurement is conducted through a flow meter. The method includes the steps of firstly, obtaining the voltage value of a power supply; secondly, monitoring whether the voltage value is lower than a preset voltage alarm value or not in real time; thirdly, when the voltage value is lower than the preset voltage alarm value, decreasing the working frequency of a controller in the flow meter, sequentially switching off switches of a converter and a field programmable gate array, and stopping supplying power to the converter and the field programmable gate array; fourthly, sending measurement data to a memorizer to be stored. Whether a power failure happens to an external power supply of the flow meter or not is monitored in real time, when a power failure happens to the flow meter, the working frequency of the controller in the flow meter is decreased, the converter and the field programmable gate array are powered off, and therefore it is ensured that when the controller has insufficient electricity, measurement data are completely written into the memorizer, and the data storage capacity of the flow meter is improved.

The invention relates to a self-adaptive matching mechanism for a drawer main body and a furniture main body. The self-adaptive matching mechanism for the drawer main body and the furniture main body comprises the drawer main body which is pulled and pushed to open and close on the furniture main body through a sliding rail assembly, wherein the sliding rail assembly is formed by at least fixed sliding rails and movable sliding rails through assembling, the fixed sliding rails are fixedly arranged on the left and right side walls of the furniture main body, and the drawer main body is detachably arranged on the movable sliding rails; the drawer main body comprises side plates, a rear back plate, a bottom plate and a front face plate, supporting portions are vertically arranged on the inner sides of the side plates in an extending manner, the bottom plate acts on the supporting portions, and the supporting portions act on the movable sliding rails; self-adaptive matching devices are arranged in the bottom areas of the side plates and are detachably matched and connected with the movable sliding rails. Through the structural improvement, the self-adaptive matching mechanism for the drawer main body and the furniture main body has the characteristics of reasonable and simple structure, reliable performance, small volume, good concealment, long service life, low manufacturing and maintenance cost, quickness and convenience in disassembly and assembly, and high practicability.

The invention discloses an efficient solar heat collector. The efficient solar heat collector comprises a heat collection pipe cluster, a reflection plate and a controller. The heat collection pipe cluster comprises a plurality of heat collection pipes arranged side by side. A sunshade pipe is arranged outside each heat collection pipe. Each heat collection pipe is formed by splicing a plurality of first arc plates concentric with the corresponding heat collection pipe. One sides of the first arc plates are hinged to the heat collection pipes through fasteners so that the first arc plates can rotate relative to the heat collection plates. The reflection plate is formed by sequentially splicing a plurality of second arc plates arranged side by side and connecting plates, and the upper portion of each connecting plate is in sliding connection with a corresponding sliding plate. The controller is arranged to control the first arc plates to rotate and control the sliding plates to slide on the connecting plates. According to the efficient solar heat collector, solar energy can be converted into heat energy and can also be converted into electric energy to be stored, and the utilization rate of solar energy is increased. The function of shielding the heat collecting pipes and the reflection base plate is achieved, and the service life of the solar water heater is prolonged.

The invention relates to a coaxial power divider of four ways or more than four ways. The coaxial power divider uses symmetrical cross branch nodes for branching a divider needing multi-way output several times. The previous cross branch node generates two directly used output ports and an output port used for the subsequent branch. If the number of ways is an odd number, the last branch is a cross branch. If the number of ways is an even number, the last branch is a T-shaped branch. Through branching several times, the high incontinuity of directly branching is broken down into low incontinuity of branching several times. The reflectivity at the lowly incontinuous positions is significantly reduced, thereby reducing the difficulty in matching and achieving wide-band equal-power division output of more than 6GHz.

The invention discloses a lock rod structure used in the electronic field. The lock rod structure comprises a lock buckle body, a first sliding wheel and a second sliding wheel. The inner side of the lock buckle body is provided with a lock buckle groove, and a lock rod head is connected to the inner side of the lock buckle groove. A pressing plate is connected to the rear side of a baffle, and a second spring is installed on the rear side of the pressing plate. A sliding handle is installed on the outer side of the first sliding wheel, and the inner side of the sliding handle is connected with the lock rod head and a pressing plate through sliding blocks. A sliding handle is connected to the outer side of the second sliding wheel, and the rear side of the sliding handle is provided with a second sliding groove. A fixed rod is installed on the inner side of the second sliding groove. The lock rod structure used in the electronic field is provided with the sliding handles and the sliding blocks, thus use of the whole device is convenient, a first sliding groove is formed in a lock rod body, working loss of the sliding blocks is lowered so as to prolong service life of the whole device, and the whole device is simple in structure, convenient to operate and has very high practical value.

The invention relates to the technical field of vibration excitation devices, in particular to a synchronous double-eccentric-shaft shock excitation device and a thin oil lubrication method. The device comprises a base, an eccentric shaft, a first oil tank, a second oil tank, a synchronous gear and an oil flinger, wherein the first oil tank and the second oil tank are arranged at the two ends of the eccentric shaft respectively, the synchronous gear is arranged in the first oil tank, and lubricating oil in the first oil tank splashes to lubricate a bearing through the synchronous gear; the oilflinger is arranged in the second oil tank and enables lubricating oil in the second oil tank to splash to lubricate the bearing; an eccentric part of the eccentric shaft is positioned outside the oil tank and rotates without hindrance, so that the working loss is low; and compared with a single large oil tank, the two small oil tanks are adopted to realize the condition that the sufficient lubricating effect can be guaranteed through a small amount of lubricating oil, the good sealing design can be achieved, and leakage is avoided. The synchronous gear and the oil flinger are matched with the design of an upper oil way, oil way circulation in the oil tank can be achieved without external power, and sufficient lubrication is achieved.

The invention discloses 5G signal base station safety equipment of an industrial internet, and belongs to the technical field of safety equipment. The 5G signal base station safety equipment of the industrial internet comprises a cabinet body, wherein a plurality of supporting plates are linearly arranged in the middle of the bottom face in the cabinet body at equal intervals, a 5G signal base station body is arranged between the top faces of the supporting plates, two air openings are formed in the middle of the top face of the cabinet body in a symmetrical structure, air pipes are fixedly arranged at the upper ends of the air openings, turbofans are coaxially arranged in the air openings, an axis is coaxially and fixedly connected to the middle of the bottom face of the turbofan, a gear sleeves the middle of the axis, a driven wheel sleeves the upper portion of the axis on the front side, a driving wheel is arranged on the right side of the driven wheel, a conveying belt is connected between the driven wheel and the driving wheel, a motor is fixedly arranged at the position, opposite to the driving wheel, of the top face of the cabinet, and a water cooling assembly is arranged below the axis. According to the 5G signal base station safety equipment, the heat dissipation of the 5G signal base station main body can be effectively facilitated, the heat accumulation is reduced, and the suitability of the working environment temperature of the 5G signal base station main body is ensured.

The invention discloses a parallel magnetic saturation fault current limiter based on a rare earth permanent magnet material. The fault current limiter comprises a magnetic core and a coil winding. The magnetic core comprises a middle column, and a left column and a right column located on the two sides of the middle column respectively. The upper and lower ends of the middle column are respectively equipped with an upper transverse yoke and a lower transverse yoke. A first permanent magnet and a third permanent magnet are embedded into the upper transverse yoke. A second permanent magnet and a fourth permanent magnet are embedded into the lower transverse yoke. The two ends of the upper transverse yoke and the lower transverse yoke are connected with the left column and the right column respectively, and the middle parts are connected with the middle column. The coil winding comprises a first coil and a second coil wound on the left column, and a third coil and a fourth coil wound on the right column. The dotted terminals of the first coil and the third coil are connected in parallel, the unlike terminals of the first coil and the fourth coil are connected in series, the unlike terminals of the third coil and the second coil are connected in series, and the dotted terminals of the second coil and the fourth coil are connected in parallel. The permanent magnet technology and the magnetically-controlled reactor technology are combined to limit the short-circuit fault current, and the current limiting effect is good. The fault current limiter is of high reliability and low cost.

The invention relates to a dismountable locking mechanism of a drawer slide rail and a side plate. The dismountable locking mechanism comprises a side plate, a bottom plate and a slide rail assembly used for opening and closing a drawer, wherein a front connecting element for connecting a front panel and a back connecting element for connecting a rear back plate are arranged on the side plate, a groove position for accommodating the bottom plate is arranged in the side plate, the bottom plate is arranged on the groove position and acts on a movable slide rail of the slide rail assembly, a dismountable locking mechanism is arranged between the side plate and the movable side rail, and the movable side rail is detachably connected with the side plate through the locking mechanism. The dismountable locking mechanism has the advantages that the groove position used for fixing the bottom plate is arranged in the side plate, the bottom plate directly acts on the movable slide rail after the assembly is completed, the drawer stress is more uniform, the work loss of each component is smaller, the service life is longer, the inner wall of the side plate is vertical, the thickness of the side plate is effectively reduced, the use space of the drawer is increased, in addition, the side plate and the movable side rail are detachably connected through the dismountable locking mechanism, the dismounting and the mounting of the side plate and the movable slide rail are fast and convenient, the manufacture and maintenance cost is low, the integral design of the drawer is favorably realized, and the drawer is tidier and more attractive.

The invention discloses a pressure differential meter which comprises a junction box, a sensor protection box and a flow regulator. The sensor protection box is arranged on the lower surface of the junction box; the sensor protection box is connected with the flow regulator; a differential pressure sensor and a pressure sensor are arranged in the sensor protection box; both sides of the sensor protection box are respectively provided with exhaust valves; the bottom of the sensor protection box is provided with a positive pressure inlet and a negative pressure inlet; the positive pressure inlet and the negative pressure inlet are respectively connected with the flow regulator. The pressure differential meter has a simple structure and is convenient to operate; measurement accuracy is improved; moreover, working loss is low and the service life is prolonged.

The invention discloses a random number sampling method for an electronic meter, and the method comprises the following steps: carrying out the collection of the flow of the meter at an initial sampling time interval t1, and obtaining the real-time flow Qs; judging whether the flow Qs is less than the starting flow of the table or not, if yes, indicating that the current instantaneous flow Q of the meter is equal to 0, and if not, indicating that the current instantaneous flow Q of the meter is equal to Qs; judging whether a gas-unused state exists or not according to the current instantaneousflow Q of the meter; if so, judging whether the duration of the gas-free state reaches preset cumulative time or not; if yes, performing flow collection every random sampling time interval t2 so thatthe current flow Qs is obtained, and the random sampling time interval t2 is a random value in a time interval [t1, t3], wherein t3 is the time interval larger than or equal to N * t1, and N is an integer larger than 1. The random number sampling method is used, the condition of short flow duration can be effectively detected, cumulant metering is carried out, the metering precision is improved and the operation power consumption of the meter can be effectively reduced.

The invention discloses a preparation method of a quasi-SMD (Surface Mount Device) crystal oscillator, which is characterized in that the preparation method comprises the following steps: coarsely grinding piezoelectric crystals by a grinding machine, and extracting a crystal bar; cutting the crystal bar into a rectangular crystal piece by a multitool machine; finely grinding the rectangular piece for four times by a lapping machine, and using a frequency division machine for frequency division so as to obtain a crystal frequency piece; cleaning the crystal frequency piece by a cleaning agent and ionized water, then using a drying machine to dewater the crystal frequency piece; storing the crystal frequency piece in a nitrogen box; and spraying a sliver layer on the crystal frequency piece by using a molecular pump vacuum coating machine, dispensing conducting resin on the crystal frequency piece with a silver layer by an automatic dispensing machine, fixing the dispensed crystal frequency piece on a base, compensating the frequency by a fine tuning machine and adding the silver layer, then sealing and soldering the crystal frequency piece on the base by a shell, instantly charging nitrogen when the sealing and soldering operation is conducted, and obtaining a finished product when the leakage check is qualified. The preparation method provided by the invention is reasonable, the cost is low, the operability is strong, the product quality can be improved effectively, and the produced product has a small size and is strong in stability.