38results about How to "Eliminate electromagnetic noise" patented technology

The invention relates to a pulse width modulation (PWM) control circuit of an elevator brake. The PWM control circuit comprises an electro-magnetic interference (EMI) filter, an alternating current / direct current converter, a high-end power switching circuit, a low-end power switching circuit, a pulse width modulation circuit, an excitation voltage regulation feedback circuit, a sustaining voltage regulation feedback circuit, an excitation control circuit, a residual magnetism removal control circuit, a freewheeling circuit, a bleeder circuit, a direct current power supply and the like. The PWM control circuit adopts a pulse width modulation mode to control the direct current working voltage of the elevator brake, thereby eliminating electromagnetic noise of the elevator brake, and improving the working stability, reliability and interference resistance of the elevator brake. The PWM control circuit can be used in various elevator brakes with different structures and other electromagnetic brakes, and can be provided with various backup and online uninterrupted power supplies (UPS).

Proposed is an apparatus for silencing electromagnetic noise, characterized by a plurality of centrally symmetrical ring-shaped through-via-hole crystalline units provided between a high voltage plane and a low voltage plane at a regular interval, thereby forming an omnidirectional noise suppression frequency band for reducing noise interference and electromagnetic radiation. In a first embodiment of the ring-shaped through-via-hole crystalline units, the through via holes are perpendicularly coupled between a metal plane and the low voltage plane. In a second embodiment of the ring-shaped through-via-hole crystalline units, the through via holes are perpendicularly coupled between two metal planes. Positioned at a regular interval, the through via holes enable provision of omnidirectional noise suppression frequency band, simplified design of a power plane, and reduction of production costs.

The present invention is to provide a cooling element for eliminating electromagnetic noise, which is formed by bending a plate into a symmetric structure symmetrically comprising a contact part being in connect with an electronic component to absorb heat and noise radiated therefrom; an extension part having one end connected with said contact part to absorb heat and noise from said contact part; and a dissipation part connected with the other end of said extension part to absorb heat and noise from said extension part; wherein the noises absorbed by the cooling element are transmitted along the paths among the contact part, extension part and the dissipation part, and are mutually offset with each other in accordance with the symmetric structure thereof.

The present invention is to provide a cooling element for eliminating electromagnetic noise, which is formed by bending a plate into a symmetric structure symmetrically comprising a contact part being in connect with an electronic component to absorb heat and noise radiated therefrom; an extension part having one end connected with said contact part to absorb heat and noise from said contact part; and a dissipation part connected with the other end of said extension part to absorb heat and noise from said extension part; wherein the noises absorbed by the cooling element are transmitted along the paths among the contact part, extension part and the dissipation part, and are mutually offset with each other in accordance with the symmetric structure thereof.

The invention discloses a magnetic conductive assembly of an electromagnetic coil. The magnetic conductive assembly of the electromagnetic coil comprises two magnetic conductive parts which are equipped with end plates; each end plate is equipped with a through hole which is in match with an inner hole in a coil part; at least one of the two end plates is fixedly equipped with a magnetic conductive sleeve which is inserted into the inner hole; two magnetic conductive parts sleeve the coil part to be fixedly connected; the magnetic conductive assembly is of a split type structure; the magnetic conductive parts and the magnetic conductive sleeves are integrally arranged; when in assembling, the inner end surfaces of the magnetic conductive parts are reliably clung to the end surfaces of the coil parts, so that the electromagnetic noise produced between the magnetic conductive parts and the coil part or between the magnetic conductive parts and the magnetic conductive sleeves in the background technology can be avoided; in addition, each magnetic conductive sleeve is inserted into the inner hole of the coil part, so that the relative positions of the magnetic conductive parts and the coil part is limited; the two magnetic conductive parts are fixedly connected are being assembled, thus the magnetic conductive assemblies are reliably located to the coil part, and the quality problem that the magnetic conductive assembly and the coil part are separated and even fallen down during being transported can be avoided. The invention also discloses an electromagnetic coil comprising the magnetic conductive assembly.

The present invention provides an elevator control device for restarting up a synchronous motor while restraining the generation of electromagnetic noise in the condition of restarting up the synchronous motor when a rotary encoder has faults. The abnormities of the rotary encoder is detected to obtain the current, flowing through armature coils, of the motor until the synchronous motor is stopped by dynamic braking, the current of the motor is used for calculating the pole position of the time point of stopping the synchronous motor, the synchronous motor is restarted up according to the pole position to move an elevator car to a given floor. Thus, the generation of electromagnetic noise when a synchronous motor is restarted up may be eliminated due to the calculation of a pole position with no need for applying voltage to the synchronous motor.

The invention discloses an electronic water pump for an automobile. The electronic water pump for the automobile comprises a pump case, a pump head, an outer shell, a rotor and a stator. The pump head is mounted on one end face of the pump case, and a pump cavity is formed through enclosure of the pump head and the pump case. The outer shell is mounted on the other end face of the pump case, and an airtight accommodating cavity is formed through the enclosure of the outer shell and the pump case. The rotor is located in the pump cavity. The stator is fixed in the accommodating cavity and surrounds the rotor. A static sealing ring is arranged between the pump head and the pump case to form a static sealing structure so that a water channel in the pump cavity can be completely isolated from the stator, and the design of a traditional dynamic mechanical sealing structure is substituted. As a result, on one hand, performance loss caused by resistance generated by dynamic mechanical sealing friction in a working process of the electronic water pump can be eliminated effectively, and the efficiency of the electronic water pump is improved; on the other hand, the situation that a water leakage fault happens because the service life of a mechanical sealing piece is shortened due to the abrasion of the mechanical sealing piece can be eliminated effectively, and therefore the reliability of the electronic water pump is improved.

The invention relates to a four-pole electric machine rotor sheet for an injection molding machine, which is specifically applied in a four-pole electric machine rotor core for the YZS280 injection molding machine with high center. The rotor sheet mainly comprises a rotor sheet body and is characterized in that the rotor sheet body is provided with 52 slots, the width of each slot is 3.8-4.0 mm, and the depth of the slot is 57-58 mm. Because the matching slots arranged on the stator and rotor sheet bodies of the electric machine are changed into 60 / 52, i.e. the number of stator sheet slots remains unchanged and the slot shape of the rotor sheet also remains unchanged, only the number of the slots of the rotor sheet is increased to 52. When the invention is used, electromagnetic noise generated by the original electric machine used at double load in a short time can be eliminated.

Proposed is an apparatus for silencing electromagnetic noise, characterized by a plurality of centrally symmetrical ring-shaped through-via-hole crystalline units provided between a high voltage plane and a low voltage plane at a regular interval, thereby forming an omnidirectional noise suppression frequency band for reducing noise interference and electromagnetic radiation. In a first embodiment of the ring-shaped through-via-hole crystalline units, the through via holes are perpendicularly coupled between a metal plane and the low voltage plane. In a second embodiment of the ring-shaped through-via-hole crystalline units, the through via holes are perpendicularly coupled between two metal planes. Positioned at a regular interval, the through via holes enable provision of omnidirectional noise suppression frequency band, simplified design of a power plane, and reduction of production costs.

The invention provides an electromagnetic heating low-power continuous output control circuit, and the circuit comprises a rectifier bridge, a controller and a heating module. The rectifier bridge comprises a first input end connected with an ACL line, a second input end connected with an ACN line, a first output end connected with the heating module, and a second output end connected with a ground end. The heating module comprises a wire coil, an IGBT tube and capacitors C1 and C2. The circuit also comprises a zero-crossing detection circuit, a feedback circuit and a feedback control circuit. The zero-crossing detection circuit is connected between the first input end and the controller and is used for feeding back the voltage change of the first input end to the controller; the feedback circuit comprises a first feedback branch and a second feedback branch; the first feedback branch circuit is connected between the first input end and the ground end, the second feedback branch circuit is connected between the first output end and the second input end, the first feedback branch circuit and the second feedback branch circuit are controlled by the feedback control circuit to be switched on or off, and charges stored in the capacitor C1 are discharged to a power grid when the first feedback branch circuit and the second feedback branch circuit are switched on.

The invention relates to a pulse width modulation (PWM) control circuit of an elevator brake. The PWM control circuit comprises an electro-magnetic interference (EMI) filter, an alternating current / direct current converter, a high-end power switching circuit, a low-end power switching circuit, a pulse width modulation circuit, an excitation voltage regulation feedback circuit, a sustaining voltage regulation feedback circuit, an excitation control circuit, a residual magnetism removal control circuit, a freewheeling circuit, a bleeder circuit, a direct current power supply and the like. The PWM control circuit adopts a pulse width modulation mode to control the direct current working voltage of the elevator brake, thereby eliminating electromagnetic noise of the elevator brake, and improving the working stability, reliability and interference resistance of the elevator brake. The PWM control circuit can be used in various elevator brakes with different structures and other electromagnetic brakes, and can be provided with various backup and online uninterrupted power supplies (UPS).

The invention discloses a TiO-containing compound with dual functions of pressure sensitivity and capacitance, which belongs to the field of information electronic components. 2 Non-linear varistor ceramic resistors and methods of making the same. The non-linear piezo-sensitive ceramic resistor is made by coating a layer of electrodes on the surface of a disc-shaped or ring-shaped ceramic substrate. The chemical composition formula of its ceramic substrate is A x B・TiO 2 . Manufacture of Bi and Pb-free TiO on ceramic substrates 2 It is a nonlinear varistor ceramic resistor, which solves the shortcomings of Bi and Pb oxides contained in the dopant in the past, not only improves the thermal shock resistance of the varistor, but also through the appropriate selection of the molar ratio and the amount of semiconducting agent And types, can improve the electrical properties of varistors, and meet the practical requirements of electrical properties. Used in DC micro-motors, it can not only effectively eliminate electromagnetic noise, but also prolong the life of the motor.

The present invention provides an elevator control device capable of restarting a synchronous motor while suppressing the generation of electromagnetic noise when restarting a synchronous motor when a rotary encoder fails. Detects the abnormality of the rotary encoder, obtains the motor current flowing through the armature coil until the synchronous motor is stopped by dynamic braking, uses this motor current to calculate the magnetic pole position at the time point when the synchronous motor stops, and uses this magnetic pole position to restart the Synchronous motors are used to move the car to a given floor. Accordingly, since the magnetic pole position can be calculated without applying a voltage to the synchronous motor, it is possible to eliminate the generation of electromagnetic noise when the synchronous motor is restarted.

The invention discloses a preparation method of an electromagnetic wave shielding / absorbing composite patch. The preparation method comprises the following steps: step 1), preparing a wave-absorbed layer; step 2), manufacturing a mixture obtained in step 1) into a sheet material through a tape casting or calendering process; step 3), carrying out vulcanization treatment on the sheet material prepared in step 2), wherein the obtained patch is the wave-absorbed layer; step 4), preparing a shielding layer; and step 5), compounding the wave-absorbed layer with the shielding layer: coating paint onthe surface of the wave-absorbed layer by adopting a spraying technology, drying and solidifying the coating, carrying out oil polish treatment on the shielding layer, and finally obtaining the composite patch. The preparation method of the electromagnetic wave shielding / absorbing composite patch provided by the invention can suppress electromagnetic radiation more effectively, and the absorbingproperty of the composite patch can be improved, thus the short circuit phenomenon can be avoided, and more electromagnetic noises can be eliminated thoroughly.

A laser-electromagnetic ultrasonic nondestructive testing system belongs to the field of nondestructive testing and evaluation of metal materials. This kind of non-destructive testing system first uses the pulse laser system to emit pulse laser, which is transported to the surface of the metal material through the line focusing optical lens, and uses the principle of thermal expansion or ablation of the surface of the metal material caused by the laser to excite ultrasonic waves, and then uses the designed electromagnetic The ultrasonic sensor can receive ultrasonic signals within the range of lift-off distance ≤ 10mm (lift-off distance refers to the distance between the electromagnetic ultrasonic sensor and the material to be detected). This system overcomes the problem that the existing laser ultrasonic detection technology is difficult to use in the detection of rough surface materials, and gets rid of the limitation that the lifting distance of the electromagnetic ultrasonic sensor must be less than 2mm. The equipment used in the system is simple, easy to operate, easy to use, and high in measurement accuracy. The repeatability is good, it is helpful to the further popularization and application of the laser-electromagnetic ultrasonic detection technology, and it has great economic and social benefits.

The invention discloses an electrical accessory for an auxiliary starting relay or an alternating current contactor. Compared with an existing product, electrical energy is saved by 65% to 80%; the calorific value of an electromagnetic coil is far less than existing calorific value, due to the fact that the calorific value of the coil is reduced, the ageing time of components and parts and insulating materials is greatly retarded, the service life of the relay is also longer, more than 90% of relays and alternating current contactors are burnt out due to excess temperature of the coil, fires further occur for several relays and alternating current contactors, the lethal link such as temperature is alleviated, except the ageing of natural materials, theoretically the service life of the working coil can be infinitely long; and the electrical accessory has ultra-wide working voltage, so that any fluctuation of network voltage can be met. In a 380 V circuit, the electrical accessory can normally and continuously work when the power supply is between 250 V and 500 V, an existing working power supply is generally between 300 V and 450 V, in a 220 V circuit, the electrical accessory cancontinuously and safely work when the power supply is between 150 V and 300 V, and an existing working power supply is generally between 180 V and 250 V; and alternating current electromagnetic vibration and noise are eliminated.

A linear actuator is an actuator for directly driving (moving) a slider. The linear actuator has an actuator unit constituted by the slider and an actuator body on which the slider is movably provided for linear movement. The actuator body has a base, a vibrating element for moving the slider, two rollers to movably support the slider, pushing means for pushing the vibrating element into contact with the slider, and a conducting circuit for conducting each of electrodes of the vibrating element by selecting a conducting pattern to each of the electrodes. Grooves are respectively formed in outer circumferential surfaces of the rollers, and the slider is arranged inside each of the grooves.

Embodiments of the present invention relate to a touch display device and a touch sensing circuit for applying to a touch display panel a no-load driving signal having a phase difference or an amplitude difference with a touch driving signal. According to the embodiment of the invention, the anti-electromagnetic noise capability can be improved, and the touch precision can be improved. The touch sensing circuit includes: a touch driving circuit configured to output a pulse-type touch driving signal to at least one touch electrode among a plurality of touch electrodes disposed on a touch display panel; and a no-load driving signal output circuit configured to output at least one no-load driving signal, the at least one no-load driving signal having a frequency equal to a frequency of the touch driving signal, and the at least one non-load driving signal has a phase difference or an amplitude difference with the touch driving signal.

The invention discloses a SF6 circuit breaker arc extinguish chamber service life prediction method based on arc energy. The method comprises the following steps: calculating rated accumulated arc energy; calculating electric arc energy borne by the circuit breaker; and obtaining the residual service life of the arc extinguish chamber by the ratio of the arc energy born by the circuit breaker to the rated accumulated arc energy. A device for measuring the arc energy on line is used for measuring the arc voltage, and a current transformer is used for measuring the arc current, so that the arc energy value is calculated on line. On the basis, the novel method for predicting the service life of the arc extinguish chamber is verified in an artificial short-circuit test. The test result shows that the life prediction result of the new method is better than that of the traditional method and is more consistent with the actual situation. The arc voltage continuously changes along with the arc current, so that the arc energy is more suitable for life evaluation. The method is favorable for realizing online state evaluation of the arc extinguish chamber of the circuit breaker.

The invention discloses a three-phase permanent magnet synchronous motor for injection molding. According to the three-phase permanent magnet synchronous motor, a permanent magnet is installed in a rotor and squirrel cage guide bar, end ring, fan blade and balance column structures are designed for asynchronous starting, control drive devices such as a frequency converter do not need to be added,a traditional three-phase asynchronous motor of the same specification can completely replaced, and the problem of low efficiency of an injection molding machine during a whole operating period, especially during light load and no-load operation are solved; and meanwhile, the three-phase permanent magnet synchronous motor adopts the measures that single-and-double-layer unequal-turn low harmonic windings are adopted to greatly reduce the high harmonic content except tooth harmonic, the tooth harmonic is reduced by being matched with a skewed stator slot and an air gap between a stator and a rotor is appropriately increased to further eliminate the unilateral magnetic tension noise caused by the decentraction of the stator and the rotor, so that the motor has low noise throughout the operating period, and especially eliminates the harsh electromagnetic noise during overload, and the motor noise is lower than the Chinese national standard requirements of 5-10dB (A).