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).

A laser-electromagnetic ultrasonic nondestructive testing system belongs to the field of nondestructive testing and evaluation of metal materials. The nondestructive testing system first uses a pulsed laser system to emit a laser pulse, which is transported to the surface of a metal material through a line focusing optical lens; a thermal expansion principle or ablation principle of the metal material surface caused by laser is utilized to motivate ultrasonic; and then a designed electromagnetic ultrasonic sensor can receive ultrasonic signal in a lift-off distance of no more than 10 mm (lift-off distance refers to the distance between the electromagnetic ultrasonic sensor and the material to be detected). The system overcomes a problem that an existing laser ultrasonic detection technology is difficult to be used for the detection of material with rough surface, so as to get rid of the limit that the lift-off distance of the electromagnetic ultrasonic sensor must be less than 2mm. The system uses simple equipment, is convenient for operation and easy for practicability, and has high measurement accuracy and good repeatability. Therefore, the system provided by the invention is beneficial to further promotion and application of laser-electromagnetic ultrasonic detection technology, and has great economic and social benefits.

A well drilling orientating sensor can achieve the high anti-interference capacity, the high precision and high guiding operation efficiency and is installed in a measurement and control system connected with a drilling-following measurement tool through an inserted shaft. The well drilling orientating sensor comprises an orientating sensor body, a magnetic orientation angular compensator and an inductive coil.

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 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 electrolysis control circuit, a disinfectant manufacturing device and an electrolysis control method. The electrolysis control circuit comprises a control chip, an electrolysis assembly, a first resistor, a second resistor and a diode. According to the arrangement, electrolysis is started with the maximum current in the electrolysis process after starting, and the voltage of the first resistor is higher than that of the second resistor, so that the diode is conducted. At the moment, the electrolysis efficiency is high. Along with the proceeding of electrolysis, the current is gradually reduced, the voltage is gradually increased, the diode is cut off at the moment, and when the current flowing through the electrode plate is smaller than the preset current and thevoltage at the two ends of the electrode plate is equal to the preset voltage, the electrolyte is electrolyzed at the preset maximum voltage until electrolysis is finished. Therefore, the electrolytic current can be well controlled, the electromagnetic noise is eliminated, and the electrolytic efficiency can be improved.

The invention discloses a low-electromagnetic-noise miniature direct-current motor and a manufacturing method thereof, and particularly relates to a miniature direct-current motor capable of effectively reducing noise and electromagnetic interference and a manufacturing method of the miniature direct-current motor. The low-electromagnetic-noise miniature direct-current motor comprises a motor device, a filtering device and a shielding ring device. The motor device comprises a stator assembly, a rotor assembly and a cover plate assembly. The filtering device comprises a network consisting of aninductor and a capacitor, is arranged at the lead end of the cover plate, and prevents an electromagnetic disturbance signal from being conducted and input into the motor; the shielding ring device is an isolation ring formed by stamping a galvanized steel sheet and is wrapped on the casing. The miniature direct-current motor, the filtering device and the shielding device are combined for use, noise caused by disturbance signals conducted and input to the motor by a power supply is eliminated or weakened, an internal magnetic field is prevented from diffusing outwards or an external magneticfield is prevented from entering, and interference is reduced.

The arc welding power supply system is formed from transformer consisting of iron core and first winding and second winding, and a auto compensator transformer is connected on the first winding of the transformer. The second winding of the auto compensator transsformer is series-connected with one end of first winding of the transformer, its first winding is series-connected with its second-winding, then is series-connected with bidirectinoal triod thyristor, finally connected on another end of first winding of the transformer, and the series-connected end of first winding and second winding of the compensator transformer is tapped and connected to power supply. The transformer and compensator transformer can be single-phase, also can be three-phase ones. The power factor is high, arc is stable, can be extensively used for transformation current regualtion and A.C and D.C. welding various metal material.

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.

Embodiments of the present disclosure relate to a touch display device and a touch sensing circuit that apply a load-free driving signal having a phase difference or amplitude difference from the touch driving signal to a touch display panel. According to embodiments of the present disclosure, electromagnetic noise immunity may be improved and touch accuracy may be increased. The touch sensing circuit comprises: a touch driving circuit configured to output a pulse type touch driving signal to at least one of a plurality of touch electrodes disposed on a touch display panel; and a load-free driving signal output circuit configured to output at least one load-free driving signal having a frequency equal to a frequency of the touch driving signal and having a phase difference or amplitude difference from the touch driving signal.

Disclosed herein is a semiconductor package including a redistribution layer and a semiconductor chip connected to the redistribution layer, the semiconductor chip being sealed with a resin layer, the redistribution layer including a ground line exposed to the side surface of the redistribution layer. The semiconductor package includes a contact metal formed on the side surface of the redistribution layer so as to cover the ground line and a shield layer formed on the upper surface and the side surface of the semiconductor package so as to cover the contact metal. The shield layer is connected through the contact metal to the ground line exposed to the side surface of the redistribution layer.

There is disclosed an ink jet recording head comprises a plurality of recording elements for applying an energy to discharge ink, a recording element driver for driving the recording elements, a control circuit for controlling the recording element driver, and a high resolution reference signal generator using a plurality of input signals continuously given from the outside in a predetermined period and generating a reference signal which has a period shorter than the predetermined period, so that recording control is performed by supplying the reference signal to the control circuit. The bluntness of a pulse waveform by the transmission of the signal via a cable, and a radiation noise generated from the cable can be inhibited, and the ink jet recording head can cope with high speed and a multiplicity of nozzles.

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.

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.