82results about How to "Suppress electromagnetic noise" patented technology

An electromagnetic noise suppressor of the present invention has magnetic resonance frequency of 8 GHz or higher, and the imaginary part μ″_H of complex magnetic permeability at 8 GHz is higher than the imaginary part μ″_L of complex magnetic permeability at 5 GHz. Such an electromagnetic noise suppressor is capable of achieving sufficient electromagnetic noise suppressing effect over the entire sub-microwave band. The electromagnetic noise suppressor can be manufactured by forming a composite layer 3 on the surface of a binding agent 2 through physical deposition of a magnetic material on the binding agent 2. The structure with an electromagnetic noise suppressing function of the present invention is a printed wiring board, a semiconductor integrated circuit or the like that is covered with the electromagnetic noise suppressor on at least a part of the surface of the structure.

A brush holder of a motor is provided with a holder body portion and a connector portion, which are integrally formed from a resin. The holder body portion is installed in a yoke housing of the motor to hold a brush to be in slide contact with a commutator. The connector portion is connected with an external connector to energize an armature. A grounding terminal is embedded in brush holder to extend from the holder body portion to the connector portion to be connected to a grounding line of the external connector. A capacitor is installed on the holder body portion to connect a point on a power supply terminal between the connector portion and the brush to the grounding terminal.

A liquid ejection head driving system includes an ink jet head, a driving circuit substrate provided with a driving circuit in which a driving signal is generated, a driving signal wiring that branches an output of the driving circuit into two or more systems, and a plurality of connectors that extract the driving signal wiring for each system, and a flexible flat substrate (FFC) in which a connector connected to a connector of the driving circuit substrate is installed, a driving signal pattern for transmitting the driving signal for each system is formed on a first layer, and a reference potential pattern is formed on a second layer. The driving circuit substrate is configured such that the same number of connectors as the number of wiring substrates are mounted at a position where a direction of insertion and extraction of the connector of the FFC is released.

A power supply apparatus suitable for a computer is provided. The provided power supply apparatus includes an isolated DC-DC converter, an auxiliary power conversion circuit and a switching circuit. The isolated DC-DC converter receives and converts an input voltage, so as to generate a first main power. The auxiliary power conversion circuit receives and converts the input voltage, so as to generate an auxiliary power. The switching circuit receives the first main power and the auxiliary power, wherein the switching circuit outputs the received auxiliary power to be served as a standby power of the power supply apparatus when the power supply apparatus is in a standby state; moreover, the switching circuit outputs the received first main power to be served as the standby power of the power supply apparatus when the power supply apparatus is in an operation state.

An image projection apparatus includes laser light sources that each emit laser light; a beam combiner combining the laser lights; a beam deflector periodically changing a traveling direction of the combined laser lights and directing the laser lights to a screen; and a controller controlling a drive current supplied to the laser light sources based on a relationship between the drive current and a total light intensity outputted from the laser light sources, in which the total light intensity comprises three ranges, the controller supplies the drive current to the laser light sources when the laser lights are emitted in the total light intensity included in either the first or the third range, and the controller supplies the drive current to at least one or some of the laser light sources when the combined laser lights are emitted in the total light intensity included in the second range.

A power factor correction conversion device and control method thereof are adapted to send an AC signal to a power factor correction conversion device, convert the AC signal into a DC signal, and perform power factor correction of the DC signal, so as to change a power factor sent to a back-end load, wherein the control method includes a rectification step, a feedback step, a ripple calculating step, a ripple offsetting step, a logical computation step, a pulse width modulation step and a power factor correcting step. Hence, the second-order ripple component in a feedback signal is eliminated to thereby increase the response speed of the power factor correction conversion device and reduce the distortion rate of the current, thus increasing the power factor sent to the back-end load.

This invention provides an electronic control unit is capable of suppressing electromagnetic noise having a frequency band used in a portable wireless apparatus, and capable of exhibiting a noise resistance property against electromagnetic noise. The electronic control unit including a constant voltage power supply circuit portion, an analog signal inputting circuit portion, and a conversion processing circuit portion, an analog sensor and a driving power supply being connected to the outside, and the unit being connected to the analog sensor through a power supply line and a signal line, in which the analog signal inputting circuit portion includes a current limiting circuit portion, an integrating circuit portion, a current limiting resistor, a signal noise absorbing circuit, and a first bypass capacitor, and capacitance (C1) and parasitic inductance (L1) of the first bypass capacitor are set in a range of 7×10⁶<1/[2π✓(L1×C1)]<35×10⁶.

The invention relates to a compensation method of motor load pulsation based on nonlinear space vector pulse width modulation and belongs to the technical field of motor control. The method detects the motor running speed and variation of motor three-phase current in real time. Whether the motor load pulsation exceeds an index value is judged; if the motor load pulsation exceeds the index value, nonlinear feedback compensation load pulsation is conducted, adjacent vector action time in space vector pulse-width modulation (PWM) is adjusted, and the motor rotation speed fluctuation caused by the load pulsation is compensated. If the load pulsation is within an allowed range, compensation is not needed, and motor control is conducted according to a traditional space vector pulse-width modulation mode. The compensation method of the motor load pulsation based on the nonlinear space vector pulse width modulation can effectively control pulsation generated by a motor under the condition that the load is carried, and the motor is enabled to run smoothly. The method can effectively suppress electromagnetic noise when a permanent magnet synchronous motor runs at high speed, and noise pollution to environment in the process of running of the motor is reduced. The working efficiency of the permanent magnet synchronous motor in the process of slow running is improved, and the application range of the motor is expanded.

A motor includes a rotor, a brush card assembly arranged to supply an electric current to the rotor, a housing, a permanent magnet, and a bearing. The rotor includes a core fixed to a shaft, a coil arranged to excite the core and a commutator connected to the coil. The coil is wound around the core in a concentrated winding method. The brush card assembly includes at least one pair of brushes having different polarities, the brushes disposed along a circumferential direction and connected to each other via the commutator and the coil, a X capacitor parallel-connected to the brushes, Y capacitors parallel-connected to the brushes and a brush card arranged to hold the brushes, the X capacitor and the Y capacitors. The brush card includes a ground portion. The X capacitor is positioned between the brushes in the circumferential direction. The Y capacitors are connected to the ground portion.

A box for an image reading apparatus, the box comprising a box body and a reinforcing member, the box body comprising a rectangular frame and a base plate fixed to the rectangular frame, and the reinforcing member being attached to the box body. The reinforcing member has a downwardly drawn area, upwardly drawn areas which are adjacent to the downwardly drawn area on front side and rear side for placing a reading block without interfering with the movement of an original document scanning unit and a cutout portion for disposing at least an image processing unit formed from the downwardly drawn area to end-of-scan side in the subscanning direction of the box body. An image reading apparatus having reduced thickness is provided by employing this box. An image forming apparatus in which height position of the image reading apparatus is set to such a height position that allows easy operation is provided.

The interference-compensated sensor (10) for detecting an object located in a detection area in a contactless manner, particularly a rain sensor, is provided with a first and a second measuring channel (12,14) each having a control device and an output (20,22), wherein both measuring channels (12,14) are substantially identical. The sensor (10) further comprises a main subtractor (24) having an output (26) for outputting the difference of the signals at the outputs (20,22) of the measuring channels (12,14). The sensor (10) is provided with a controller unit (30) having an input that is connected to the output (26) of the main subtractor (24) and with an output for outputting a controller signal, by means of which the two measuring channels (12,14) can be controlled in such a way that the signal at the output (26) of the main subtractor (24) can be controlled to zero. By means of the magnitude of the signal at the output of the controller, it can be determined if an object is located in the detection area.

The invention discloses a stator assembly and a motor. The stator assembly comprises a stator core and a stator winding, the stator core is provided with N grooves, the stator winding is formed by winding a plurality of hairpin coils in the grooves, each phase of stator winding comprises two sub-windings, each sub-winding is provided with a plurality of hairpin coils, and the hairpin coils are distributed in L different layers of the N grooves. The plurality of hairpin coils of each sub-winding comprise a first hairpin coil positioned on a first layer, a second hairpin coil positioned on an Lth layer, and middle hairpin coils positioned between the first layer and the Lth layer; one of the two first hairpin coils is a long-distance hairpin coil, the other hairpin coil is a short-distance hairpin coil, one of the two second hairpin coils is a short-distance hairpin coil correspondingly, and the other hairpin coil is a long-distance hairpin coil; the total number of the middle hairpin coils of the two sub-windings is the same, the pitch types of the middle hairpin coils are the same, and the distribution of the pitch types is the same. Counter electromotive force, resistance and inductance of all the sub-windings are the same, and the assembly efficiency of the windings is improved.

The invention provides a split pole-changing variable-speed outer rotor asynchronous motor and relates to a motor. The split pole-changing variable-speed outer rotor asynchronous motor comprises a stator component and a rotor component. By changing a connection type of a working winding coil in a working winding circuit and changing the connection type of a starting winding coil in a starting winding circuit at the same time, the quantity of stator magnetic poles of the motor is adjusted, pole changing and speed changing of the motor are realized, and the demand of a blower-pump load on a low-cost small-type motor energy saving technology is met. When the motor operates at a low speed gear, a silicon controlled chopping speed regulation method is adopted for lowering the terminal voltage of the motor, compared with the technical scheme that a common outer rotor asynchronous motor adopts the silicon controlled chopping speed regulation method for obtaining the same low rotational speed, the reduction extent of the terminal voltage of the motor is relatively small, waveform distortion of silicon controlled alternating current voltage is relatively small, electromagnetic noise of the motor during operation at a low rotational speed can be effectively inhibited, the copper loss of the motor is reduced, and the motor efficiency is improved.

Provided is an in-vehicle step-down switching power supply capable of obtaining a stable output while suppressing nose in a harmful frequency band even when an input voltage decreases. The in-vehicle step-down switching power supply includes a switching frequency control unit and the switching frequency control unit includes a switching frequency range setting unit that changes a switching frequency between fa and fb and a switching frequency path setting unit that skips a frequency band from fd to fe between fa and fb, via an intermediate frequency fc between fa and fb.

The invention discloses a control method and device for an air conditioner, a storage medium and the air conditioner. The method comprises the following steps: adjusting carrier frequency of an inverter compressor in the air conditioner so as to obtain current carrier frequency; determining current driving parameters of the inverter compressor according to the current carrier frequency; and controlling the air conditioner to run according to the current driving parameters. According to the scheme disclosed by the invention, the problem that an inverter air conditioner has high electromagneticnoises can be solved and the effect of reducing the electromagnetic noises is achieved.

The invention provides a PFC jitter frequency control method, a PFC jitter frequency control system and an electric appliance. The PFC jitter frequency control method comprises steps of controlling aPFC frequency jitter module to generate a PFC carrier frequency periodically changing with the time through a PFC carrier jitter frequency function; obtaining the phase of a mains supply voltage signal, and controlling the PFC carrier frequency corresponding to each frequency point of the PFC carrier jitter frequency function to periodically change along with the phase of the mains supply voltagesignal; wherein the minimum frequency point and the maximum frequency point of the PFC carrier frequency function correspond to a zero crossing point phase of the mains supply voltage signal, and thezero crossing point phase of the PFC carrier frequency function corresponds to the minimum frequency point and the maximum frequency point of the mains supply voltage signal. The method is advantagedin that the electric stress of power devices such as an IGBT or an MOS in the PFC circuit can be effectively reduced, switching loss is reduced; electromagnetic noise of household appliances or powersupplies and other products can be effectively suppressed, and electromagnetic interference to the outside is reduced.