113results about How to "Avoid burning" patented technology

The invention discloses an LED (light-emitting diode) backlight source. The LED backlight source comprises a boosted circuit (210), a plurality of parallel LED strings (220), an over-current protection circuit (230) and a short-circuit protection circuit (240), wherein the boosted circuit (210) is used for boosting input direct current voltage and outputting boosted direct current voltage; each LED string (220) comprises a plurality of LEDs and a first resistor (221) which are connected in series, and each LED string (220) is used for receiving the boosted direct current voltage from the boosted circuit (210); the over-current protection circuit (230) is used for controlling the output power of the boosted circuit (210) according to the detected resistance; the short-circuit protection circuit (240) is used for controlling and regulating the resistance detected by the over-current protection circuit (230) according to voltages at two ends of the first resistor (221). According to the LED backlight source disclosed by the invention, when the resistor of one LED string is in short circuit, the output power of the boosted circuit is reduced to prevent a circuit device in a driving circuit from being burned up, and the security and reliability of the driving circuit are improved. The invention further discloses a liquid crystal display.

The invention relates to a switch power controller and a short-circuit protection method of a current control end thereof, which are used for a switch power system. The method comprises the following steps of: generating a window signal with preset width while generating a PWM (Pulse Width Modulation) signal of the switch power controller; comparing a voltage of a current control signal input from the current control end of the switch power controller with a threshold voltage, and outputting a comparison voltage, wherein the voltage of the current control signal is gradually increased in the conduction period of the PWM signal; trigging the detection of the comparison voltage by the window signal, and determining whether to trigger a first reset signal according to the comparison voltage, wherein the first reset signal is used for carrying out resetting on the PWM signal of the current period; and triggering a second reset signal by hop of the comparison voltage, wherein the second reset signal is used for carrying out resetting on the PWM signal of the current period, and when the PWM signal is reset, a power switch is switched off by a power switch actuator, and thus primary side current of a transformer can be prevented from continuously increasing.

The invention provides an air conditioner control method and control device as well as the air conditioner. The air conditioner control method comprises the steps that the working state of a compressor is detected; when the compressor is shut down, whether the air conditioner has started the built-in protection of the compressor is judged; when the built-in protection of the compressor is judged to be started, the starting frequency of the built-in protection of the compressor is recorded, and in the preset time, whether the starting frequency is larger than or equal to a first preset threshold value or not is judged; when the starting frequency is judged to be larger than or equal to the first preset threshold value, the compressor is controlled to stop, and a fault signal is sent out; and when the starting frequency is judged to be smaller than the first preset threshold value, a built-in protector of the compressor is controlled to automatically reset, and the working state of the compressor is continuously detected. According to the technical scheme of the air conditioner control method, under the condition of refrigerant leakage, the compressor is prevented from being burnt due to frequent protection, so that the protection in a higher degree is realized, the self-protection capability of the air conditioner and the compressor during refrigerant leakage is enhanced, and operation reliability of a whole machine is improved.

The invention relates to a method for preparing an Mg-Li alloy by vacuum synchronous thermal reduction, belonging to the novel technical field of preparing magnesium alloy materials. The process course comprises the following steps of: preparing reactants according to stoichiometry of reduction reaction; pulverizing solid reactants and uniformly mixing; pressing the reactant powder into blocks and placing the blocks into a reduction tank, and carrying out thermal reduction reaction at the vacuum degree of 1-20Pa and the temperature of 950-1,500 DEG C; collecting alloy steam generated by reaction; and condensing the alloy steam to obtain an Mg-Li alloy in a condensed state. In the invention, the oxides of metals Mg and Li or a precursor of the oxides are utilized as raw materials, the synchronous reduction of the metals Mg and Li is realized through vacuum thermal reduction to prepare the Mg-Li alloy directly. The alloy preparation process has short route, wide sources of the raw materials, high material utilization rate, favorable economy and manufacturability, high efficiency and energy saving.

The invention discloses a conveniently used energy-saving motor, which comprises a base, and is characterized in that the internal part of the base is provided with cavities which are arranged at equal intervals, the internal part of each cavity is fixedly connected to a first shock-absorbing spring, the top of the base is provided with an accommodating cavity, the upper part of the inner side wall of the accommodating cavity is fixedly connected with two symmetric limiting blocks, the inner side wall of the accommodating cavity is provided with two symmetric sliding slots, a movable plate matched with the accommodating cavity is placed in the accommodating cavity, the upper surface of the movable plate is contacted with the bottom of the limiting blocks. According to the conveniently used energy-saving motor, a simple air convection channel can be formed, the flowing speed of the air is accelerated, the head can be dissipated quickly, a phenomenon of burning loss of the motor is effectively avoided, the heat dissipation effect is good, a shaking force of the energy-saving motor can be effectively released, a shaking force of a storage box can be effectively buffered, the shake absorbing mode is more diversified, the shake absorbing performance is good, and the use is more convenient.

The invention discloses a universal clamp for machining pin holes of ball-head screws. The universal clamp comprises a drilling die bracket arranged on the right end surface of a V-shaped base, wherein a drilling sleeve is embedded into a hole on the drilling die bracket; a drilling die is arranged in a hole of the drilling sleeve; the right end surface of the V-shaped base is provided with a key groove which is internally provided with a guide key by a fixed bolt; the center line of the key groove is consistent to the center of a V-shaped surface; the right end surface of the V-shaped base is also provided with a ball bowl which is provided with a handle; the ball surface of the ball bowl is matched with the ball surfaces of the top ends of the ball-head screws, and the other surface of the ball bowl is matched with the inner side surface of the drilling die bracket; the center of the drilling die bracket is provided with a vertical U-shaped through groove which is matched with the guide key. The universal clamp disclosed by the invention has the advantages that the pin holes of the ball-head screws with different specifications are conveniently machined, the production accuracy is improved, the production cost is reduced, the production efficiency is improved, the phenomena of wearing, chip falling and burning in use of the ball-head screws are effectively avoided, and the production need is met.

The invention provides a display device and a source electrode driver thereof, wherein the source electrode driver comprises a temperature sensor and a power switch. The temperature sensor is used for measuring a first operation temperature of the source electrode driver, and generates an overtemperature protection starting signal through comparing the first operation temperature with a first preset temperature. The power switch is coupled in a power transmission path of a core circuit of the source electrode driver for receiving the operating power. The power switch switches on or off the power transmission power according to the overtemperature protection starting signal.

The invention discloses a high-energy multi-state low-temperature ionizer, comprising an internal electrode and an external electrode, wherein the internal electrode and the external electrode are respectively connected with a power supply. The internal electrode and the external electrode are both tubular structures, and a hollow cavity of the internal electrode is a cooling channel; two ends of the internal electrode and two ends of the external electrode are respectively provided with an electrode support, and the two ends of the internal electrode and the two ends of the external electrode are respectively fixed on the electrode support; the internal electrode is sleeved in the external electrode, and an ionization channel is formed between the external surface of the internal electrode and the internal surface of the external electrode; two ends of the ionization channel are respectively provided with an aerial fog input port and an aerial fog output port, and the aerial fog input port and the aerial fog output port are respectively communicated with the ionization channel. The ionizer provided by the invention is simple in structure and convenient to use, the cooling channel is formed at the center of the internal electrode, when working, the cooling channel can cool the ionization channel so as to generate a large amount of low-temperature plasmas, the cooling effect is better, and the generated plasmas have high energy charge.

A door lock actuator enabling a motor to not be electrified in the state of mechanically limiting actions is characterized in that a cam component (4) is equipped with a first operation part (13) and a second operation part (14), the first operation part (13) is rotated further at a locking complete angle to enable a switch component (7) to swing towards an unlocking drive region in which a movable contact (20) is contacted with a first fixed contact (27) and a second fixed contact (28) and is not contacted with a third fixed contact (29), and the second operation part (14) is rotated further towards the unlocking direction at a unlocking complete angle to enable the switch component (7) to swing towards a locking drive region in which the movable contact (20) is abutted against the first fixed contact (27) and the second fixed contact (28) and is not abutted against the third fixed contact (29). By swing a locking component (6) to the locking position and the unlocking position, the switch component (7) swings towards a transaction region in which the movable contact (20) is contacted with all the fixed contacts (27, 28, 29).

The invention discloses a control method and a control device of a slow speed type electric valve. The control method is characterized in that a control box is internally provided with a ripple time relay, thereby achieving the purpose of adjusting the rotation speed of an electric valve motor and the running time in the opening and closing process. The control method not only can prevent a pipeline from generating a water hammer when the electric valve is rapidly opened and closed, and the deformation and detonation of the pipeline are avoided; and a valve electromotion device is prevented from abidingly operating for a long time, the burnt phenomenon of the valve electromotion device is avoided, the power of a motor is reduced, and the investment cost and operating cost are reduced.

The invention discloses an internal heating type anti-freezing cable for a severe cold area and an anti-freezing method thereof, belongs to the technical field of cables, and can realize that a contraction action is triggered after external cold is sensed by arranging cold sensing outer coating scales outside the cable, so that the cable can be prevented from being frozen. Pre-filled magnetic heat-generating microspheres are subjected to powder scraping and adsorption by virtue of shrinkage action, and then an external gap is opened to be communicated with the outside after the magnetic heat-generating microspheres are shrunk to a certain extent, so that a small amount of external air enters the cable and is subjected to an oxidation reaction of releasing heat with the scraped powdery magnetic heat-generating microspheres, a gentle heating environment can be formed in the cable, on one hand, the cable can be assisted to resist external cold, on the other hand, burnout caused by excessive heat release can be avoided, technicians can regularly supplement the magnetic heat generation microspheres to realize autonomous low-temperature protection action of the cable, the use safety of the cable in severe cold areas is effectively improved and the service life is greatly prolonged.

The invention relates to the laser field and discloses a large-aperture polarization independent high-power isolator. The large-aperture polarization independent high-power isolator comprises a first birefringent prism, a 45-degree faraday rotator, a second birefringent prism and a beam combiner, all of which are orderly arranged in the forward transmission direction of a light path, wherein the first birefringent prism and the second birefringent prism both are reflective polarizing beam splitting prisms; a half-wave plate is optically cemented on a light transmission surface at the magneto-optical crystal side of the faraday rotator. The birefringent prisms of the reflective polarizing beam splitting prisms are employed to divide light transmitted in the isolator into two beams of polarized light, the polarization directions of the two beams of polarized light are perpendicular to each other and a large separation angle is formed between the two beams of polarized light, and a pair of total-reflection optical elements is employed to further reflect two sub-beams of the returned light so that the two sub-beams are deviated away from the forward transmitted light, and therefore, the large-aperture polarization independent high-power isolator is realized; the half-wave plate is added on the side of the magneto-optical crystal so that the isolation of the isolator is enhanced, and as a result, the high-power isolator is enabled to be more stable and reliable and can be prevented from being burnt out.

The invention discloses an arrangement rod bundle positioning structure for a reactor thermal-hydraulic experiment. The arrangement rod bundle positioning structure comprises four outer sleeve pieces. The outer sleeve pieces are welded to form a square cavity structure, inner fixing rings are arranged at the axes of the outer sleeve pieces, the inner sides of the outer sleeve pieces are provided with four heating rod bundles, the heating rod bundles are tangent to and fixed to the inner fixing rings through two adjacent outer sleeve pieces, and the outer sides of the outer sleeve pieces are fixed to the side wall of a runner through equidistant pieces. The arrangement rod bundle positioning structure can rotate, so that reasonable disturbance is caused through heating, local burnout is avoided, and the whole arrangement rod bundle positioning structure is reasonable in structure, suitable for the thermal-hydraulic experiment of a rod bundle fuel assembly and high in substitutability. Besides, the arrangement rod bundle positioning structure is very low in cost; compared with a framework, cost of the arrangement rod bundle positioning structure is only 20%, and the positioning reliability is guaranteed.

The invention discloses a medicinal material drying device, which relates to the technical field of traditional Chinese medicinal material processing equipment. The invention includes a drying tank body and a tank cover matched with the drying tank body. The drying tank body includes an inner container and an outer shell, and the inner container and The outer casing constitutes a heating cavity, and a circulating hot water pipe is arranged around the inner tank in the heating cavity. Feeding hopper and exhaust port, an intermittent feeding box is arranged above the feeding hopper, a stirring shaft is arranged in the inner tank, and the stirring shaft is connected with a motor that drives the stirring shaft to rotate in the inner tank. Regularly and intermittently feed materials to the drying tank, and continuously stir the medicinal materials during the heating process, which can make the medicinal materials evenly heated, avoid burning the medicinal materials, and improve the drying efficiency, and the drying effect is good.

The invention relates to a raw material preparation device of a straw biomass organic fertilizer, and belongs to the technical field of biomass organic fertilizer preparation. The device comprises a pedestal, a charging box, a cutting device, a swinging device, a driving mechanism and a collecting drum, the pedestal comprises a base plate, a main support, a charging box support, an auxiliary support, a motor rack, a main shaft lower support, a main shaft upper support and a collecting drum support, the main support is fixedly connected to the right end of the base plate, the charging box support is fixedly connected to the top end of the main support, the auxiliary support is fixedly connected to the front end of the base plate, and the motor rack is fixedly connected to the middle end ofthe auxiliary support. The cutting device cuts different straws into segments, a crushing device crushes the segments, the crop straws in different length, thickness and hardness can be processed effectively, and during use, it is only required put the straws in the charging box to realize automatic cutting, crushing, screening and discharging, and the workload of straw processing of farmers is reduced.

The invention discloses a freeze prepared eel skin and a preparation method thereof. The eel skin is subjected to preprocessing, stripping and slicing, fishy smell eliminating, seasoning meat strips rolling, binding, stewing or frying, quick-freezing, bagging and cold storing to obtain the freeze prepared eel skin. According to the freeze prepared eel skin and the preparation method thereof, the deep development and utilization of eel processing by-product eel skin are realized, raw material sources are various, the cost is low, the preparation method is simple, the product is full of nutrition, mouthfeel is excellent, and the freeze prepared eel skin and the preparation method thereof have remarkable economic and social benefits.

The invention discloses a plastic extruder for producing chairs. The plastic extruder comprises a barrel of which one end is fixedly provided with a first driving motor, and the driving end of the first driving motor is connected to a first rotating shaft; one end, far away from the first driving motor, of the first rotating shaft penetrates the side wall of the barrel, and extends into the barrel; and one end, located in the barrel, of the first rotating shaft is fixedly connected to a screw conveyer. According to the plastic extruder disclosed by the invention, the inside wall of the barrelis provided with a thermal insulating layer, so that the operation of the first driving motor is prevented from being affected by high temperature of molten plastic colloid in the barrel; the barrel and the colloid in the barrel are cooled in time through spiral cooling pipes wound on the outside wall of the barrel, and the colloid in the barrel is prevented from being charred; and through the driving effect of the first driving motor, relative rotation between a first grinding disc and a second grinding disc is formed, thereby facilitating grinding of plastic particles in the plastic colloid,and the smoothness of plastic parts and the product quality are improved.

Embodiments of the invention relate to the technical field of motor control, and disclose an over-current protection method, device and system, and an unmanned aerial vehicle. The over-current protection method comprises the following steps: acquiring a present throttle of the motor and a present current corresponding to the present throttle; generating a preset throttle current curve; determininga threshold range of the present current according to the present throttle and the preset throttle current curve; if the value of the present current exceeds the threshold range of the present current, determining that the motor is in an abnormal state; and if the motor is in an abnormal state for more than a preset time threshold, performing over-current protection. In the above manner, the invention can perform over-current protection when the motor is stalled, thereby preventing the motor from being burnt.

The invention belongs to the technical field of power system relay protection, and specifically relates to an intelligent controller for preventing switch trip and coil burnout, solves problems of a circuit breaker trip control loop, and mainly improves the switch trip reliability and prevents the trip coil burnout. The controller achieves the intelligent control of an original switch control loop, and effectively prevents the burnout of a switch trip coil and a switch rejection accident caused by a switch auxiliary contact. The controller also provides the functions of trip coil breakage monitoring, circuit breaker auxiliary contact reliability monitoring, trip coil temperature monitoring and switching-on pulse recording of all parts.

The invention discloses a converter slagging device and a method for controlling converter slagging, and the device comprises a slagging runner in a platy structure and a retaining wall, wherein the slagging runner is aslant fixed on a buggy ladle and is arranged in front of the steel ladle on a converter tapping direction, the slagging runner comprises a first surface back to the surface of the buggy ladle and a second surface facing to the surface of the buggy ladle, and the slagging runner comprises a first end and a second end lower than the first end along the height direction; and the retaining wall comprises a first retaining wall and a second retaining wall respectively fixed on the left side and the right side of the first surface of the slagging runner to limit the channel for the flowing of converter slag. The phenomenon that steel slag falls in the ladle in the process of reducing the titling angle of the converter after the molten steel in the converter is completely discharged, the quality of the molten steel is improved, and the steel slag is prevented from splashing to the buggy ladle to burn the buggy ladle and the support equipment.

The invention discloses an internal mixer for rubber mixing. The internal mixer comprises an internal mixer body. A feeding opening is formed in the outer wall of one side of the internal mixer body,and a feeding hopper and a mixing chamber are formed in the internal mixer body. The feeding hopper is located above the mixing chamber, and an upward-jacking bolt is mounted in the middle of the feeding hopper. A second motor, a screw, a second guide rod, a fixing seat, a driving gear, a driven gear and a screw sleeve are arranged, during unloading, firstly, an PLC controls a first motor to startto work, the first motor drives the driving gear to rotate through a rotary shaft, the driving gear is engaged with the driven gear and drives the screw sleeve to rotate through the driven gear, thescrew sleeve is in rotating fit with the screw when rotating, and thus the purpose of screw ascending is achieved; and when ascending, the screw drives the upward jacking bolt to move upwards throughthe second guide rod till one end of the second guide rod makes contact with the screw sleeve, in the unloading process, the upward jacking bolt is started, and on the one hand, the discharging pressure of a downward jacking bolt can be relieved.

The invention discloses a centrifuge for automatically separating pulp and dregs. The centrifuge comprises a machine bin for fixing a gearbox and a stepping motor, and a liquid collecting bin for filtering, wherein the stepping motor is connected to the gearbox through a driven shaft; a liquid outlet is formed right below the liquid collecting bin; a feeding tube for conveying a material is arranged at the outer side of the liquid collecting bin; the output end of the gearbox is connected to a filtering frame in the liquid collecting bin through a rotating shaft, so that the gearbox drives the filtering frame to rotate; the filtering frame has a frame structure of which the outer end is provided with an opening and the middle is provided with a filtering screen; the output end of the feeding tube extends into the filtering frame from the opening end of the filtering frame; a dreg outlet is formed in the bottom part of the liquid collecting bin at the outer part of the opening end of the filtering frame. According to the centrifuge, a washing plate reciprocates in the filtering frame, so that the material on the filtering screen can be removed without stopping the centrifuge, and as a result, the working efficiency can be greatly improved.

The invention discloses a multifunctional environment-friendly garbage can which comprises a base and an inner cylinder. The inner cylinder is fixed in the base. Four angles in the upper surface of the base are respectively provided with supporting rods. Each supporting rod is provided with a water collector. Each water collector directly facing the bottom of the inner cylinder is provided with a firefighting spray system. Two sides of each water collector are provided with anti-overflow drain pipes. The top of each water collector is in an opening structure. The upper end of each opening is provided with a filter screen. A groove is formed between the inner wall and the outer wall of the opening end of each water collector. The multifunctional environment-friendly garbage can has the advantages that each water collector directly facing the bottom of the inner cylinder is provided with the firefighting spray system, the rainwater collected by the water collectors can be used for putting out the fire occurs in the garbage can, the groove which is formed between the inner wall and the outer wall of the opening end of each water collector can be used for being planted with some flowers and plants so that the problem of single function of the garbage can is solved.

The invention provides an outdoor barbecue grill, and relates to the field of barbecue equipment. The outdoor barbecue grill comprises a grill frame, a charcoal placing plate, a grill body, a supporting plate, a storage box and a ventilation mechanism, a rectangular groove is formed in the outer wall of one side of the grill frame, a sliding groove is formed in the inner wall of the bottom end of the grill frame, the inner wall of the sliding groove is slidably connected with the charcoal placing plate, and the supporting plate is movably connected with the outer wall of the bottom end of the grill frame through a hinge; the inner walls of the two sides of the barbecue grill are connected with the storage box in an inserted mode, the barbecue grill is connected with the inner wall of the barbecue grill frame in a clamped mode, and the ventilation mechanism is arranged on the barbecue grill frame located below the barbecue grill. According to the invention, the direct contact area of kebabs and the hollow pipes is reduced, and the cavities are formed in the hollow pipes, so that heat conduction is slow, the kebabs are prevented from being burnt due to overheating of the barbecue grill in the contact process with the kebabs, oil cannot directly drip on charcoal, open fire is reduced, and the temperature of all positions in the barbecue grill is more stable.

The invention relates to a resonance elimination apparatus and a resonance elimination system. The resonance elimination apparatus comprises a three-phase five-column type reactor and a damping resistor, wherein the three-phase five-column type reactor comprises reactor primary windings and reactor secondary windings, one end of each reactor primary winding is grounded in parallel, the other end is used for connection with a three-phase power source, the reactor secondary windings are connected in series to form an opening triangle, one end of the opening triangle is grounded, the other end is connected with one end of the damping resistor, and the other end of the damping resistor is grounded. The resonance elimination system comprises an electromagnetic voltage transformer, a three-phase power source and the resonance elimination apparatus. According to the resonance elimination apparatus and the resonance elimination system provided by the embodiments of the invention, when a single-phase grounding fault takes place in a power system, a low-impedance discharge channel of grounding capacitive currents is provided, burning damage of an electromagnetic voltage transformer and fusion of an electromagnetic voltage transformer fuse are effectively prevented, and the operation stability, safety and reliability of the power system are enhanced.

The invention discloses an antiresonant three-phase four-wire integrated casting insulated mutual inductor. In the mutual inductor, terminals of primary winding coils of three voltage mutual inductors are mutually electrically connected, and the other terminals of the primary winding coils are respectively connected to primary connecting terminals; winding coil measuring tail ends of secondary sides of the three voltage transformers are mutually connected and used as grounding ends, and start ends thereof are respectively connected to secondary connecting terminals; protective winding coils of the secondary sides of the three voltage transformer are sequentially, serially and electrically connected in an opened triangle pattern, damping resistors are connected in series among the openings of the opened triangle, and output ends of the opened triangle formed by the serial connection are respectively connected to the secondary connecting terminals; and the three voltage mutual inductors are cast by insulation materials to form a fully enclosed casting body arranged in a shell. The mutual inductor can effectively absorb high order harmonic elements of secondary circuits by the damping function of the damping resistors so as to prevent the output circuit from resonance and prevent the transformer from being burnt down due to the ferromagnetic resonance.

The invention relates to the field of copper alloys for toilet and kitchen industries, and provides a preparation method of an anti-dezincification lead-free bismuth arsenic brass pipe. The preparation method comprises the steps of casting as a copper ingot-extrusion as a copper pipe blank-stretching-annealing-inspection of a finished copper pipe-warehousing of the finished copper pipe after smelting of the following raw materials in percentage by mass: 61-63% of Cu, 0.5-0.9% of Bi, 0.07-0.12% of As, 0.5-0.8% of Al, 0.08-0.24% of Sn, Pb not more than 0.1%, and the balance of Zn and impuritieswith a total amount not more than 0.25%.

The invention discloses an over-temperature protection circuit of a fan board, and a server system. The over-temperature protection circuit comprises a temperature detection circuit for detecting thetemperature of a power supply input port of the fan board, and a power supply control circuit; and the power supply control circuit is used for utilizing a fan board input hot-plugging chip to cut offpower supply input of the fan board when the temperature is not smaller than a preset temperature threshold value. Compared with other positions of the fan board, the power supply input port of the fan board has fastest temperature rise and maximum heat accumulation, thus the temperature of the power supply input port of the fan board is detected, if the temperature is smaller than the preset temperature threshold value, the fan board is considered to be in a safe state, and a protection action is not executed; and if the temperature is not smaller than the preset temperature threshold value,the fan board is considered to be in an over-temperature state, then power supply input of the fan board is cut off through the fan board input hot-plugging chip, it is guaranteed that the fan boarddoes not have a heat accumulated energy source, thus the fan board is prevented from being burned, and the safe reliability of the server system is improved.

The invention discloses a glass lifting control device with a maximum stroke protection function, and relates to the technical field of control. The glass lifting control device comprises an output shaft, wherein the inner wall of the output shaft is fixedly connected with elastic sheets which are uniformly distributed; the inner wall of the output shaft is fixedly connected with springs; the outer sides of the springs are fixedly connected with movable blocks; and the outer sides of the movable blocks are rotatably connected with rollers. According to the glass lifting control device with the maximum stroke protection function disclosed by the invention, blocking blocks are matched with gears for use, so that when a motor works, the output shaft drives the gears to rotate, and the gears do not rotate when a car window moves to the maximum stroke, and therefore, the output shaft continuously rotates through action of the motor; moreover, the blocking blocks are extruded into a mounting base while the output shaft drives the mounting base to idle on the middle parts of the gears, so that an overload operation condition of the motor is avoided, and therefore, the effect of protecting the motor is achieved, the motor is prevented from being burnt as a result of over-load operation, and the service life of the motor is prolonged.