44results about How to "Eliminate Harmonic Interference" patented technology

The embodiment of the invention discloses an anti-harmonic interference device for carrier aggregation, an antenna device and a mobile terminal. The anti-harmonic interference device comprises a first duplexer of which the sending terminal is connected with a first uplink interface in a power amplifier, wherein the first uplink interface is used for sending uplink signals in a first band, and the receiving terminal of the first duplexer is used for sending downlink signals in the first band to a wireless transceiver; a second duplexer of which the sending terminal is connected with a second uplink interface in the power amplifier through a first filtering unit, wherein the second uplink interface is used for sending the uplink signals in a second band, and the receiving terminal of the second duplexer is used for sending the downlink signals in the second band to the wireless transceiver, and there is overlap between the frequency of the harmonics of the uplink signals in the first band and the frequency of the downlink signals in the second band; and the first filtering unit which is used for filtering the part in the harmonics of the uplink signals in the first band overlapping with the frequency of the downlink signals in the second band. According to the embodiment of the devices and the mobile terminal, the scheme for eliminating carrier aggregation harmonic interferences is small in size and low in cost.

The present invention relates to an excitation method and device of a vibrating wire instrument. The method generates a SPWM wave, and then filters the generated SPWM wave through a filter circuit to obtain a sinusoidal waveform signal, and then applies the sinusoidal waveform signal to the vibrating wire instrument. The two ends of the frequency measuring coil in the instrument generate alternating electromagnetic force under the action of the permanent magnet, which drives the steel string to generate resonance. The SPWM waveform excitation signal whose pulse width changes according to the sinusoidal waveform rule generated by the method improves the precise control ability of the excitation signal and solves various limitations caused by the traditional excitation method using a pulse square wave.

The present invention discloses a passive mixer which comprises an input resistance circuit that including: a first electric resistance, a second electric resistance and a switch tube that connected in series, wherein, source electrode and drain electrode of the switch tube is respectively bridge connected to two ends of the first electric resistance, and grid of the switch tube is connected to local oscillation signal VLOO while the drain electrode is connected to voltage signal VIN; a switch converting circuit that used to frequency convert electrical current signal flow from converted VIN under control of VLOO by input resistance to output frequency; electrical current voltage convert circuit that used to convert electrical current signal after frequency conversion to voltage signal to output. Through adopting switch tube in input resistance branch path, harmonic interference can be effectively dispelled, and problems like harmonic interference oversize and that leading to output desired signal most likely be inundated by harmonic interference signal hence system unable work in existing passive mixer can be overcome.

The invention claims a method for eliminating harmonic interference of earthquake data, comprising the following steps: according to the original waveform data in the earthquake data, determining the initial frequency of harmonic interference through the oscillation period of the original data and the maximum position of the amplitude spectrum; calculating the amplitude of the harmonic interference cosine function; and according to the earthquake data vector, the amplitude of harmonic interference cosine function, the harmonic interference cosine function vector and the target function derivative, the harmonic interference frequency amendment quantity and the time delay amendment quantity, adopting a frequency modifier formula to determine the harmonic interference frequency; and calculating the effective signal of earthquake. The method overcomes the disadvantage that the frequency domain suppresses the harmonic interference, and is quicker in speed than the time domain harmonic interference suppressing method, thereby improving the signal-to-noise ratio, and being capable of eliminating the harmonic interference in the earthquake data generated by high voltage transmission line and also eliminating the harmonic interference in the earthquake data generated by periodic vibration.

The invention discloses an electricity saving device, comprising a system control module, a main loop control module and a chopper, wherein the main loop control module is respectively connected with the system control module and the chopper. The system control module is used for receiving the working condition data of a power grid, sent by the main loop control module, and setting the voltage reduction parameters of the main loop control module; the main loop control module is used for generating four groups of pulse width modulation signals according to the voltage reduction parameters and outputting the four groups of pulse width modulation signals to the chopper; and the chopper is used for receiving the voltage of the power grid, completing voltage reduction according to the four groups of pulse width modulation signals and outputting the voltage to loads. Based on the technical scheme, the automatic voltage stabilization type electricity saving device is provided, and by means of the technical scheme, harmonic interference is eliminated and voltage-stabilizing output is realized. In addition, according to the technical scheme, when the voltage of the power grid is lower thana preset low-voltage threshold, the power grid automatically quits an electricity-saving working state and the voltage of the power grid is directly transmitted to the loads.

The invention discloses a radio frequency matching circuit and a radio frequency system. The radio frequency matching circuit comprises an L-form matching circuit, a first transmission line and a second transmission line, wherein the first transmission line and the second transmission line are connected to form two sections of open circuit transmission lines in parallel; a transmission line connection point is formed between the first transmission line and the second transmission line; the transmission line point is connected with the L-form matching circuit and can be arranged at the output end of a radio frequency power amplifier and used for an in-band signal power loss problem of the radio frequency (especial the wide frequency band radio frequency), and the echo interference is greatly reduced; the radio frequency system comprises radio frequency transmitting/receiving circuits connected in order, the above-mentioned radio frequency matching circuit, a filtering circuit and an antenna, wherein the lengths of the first transmission line and the second transmission line are different. The system disclosed by the invention can make improvement on a wide frequency band power loss problem and shorten the radio matching debugging time when changing the frequency band port impedance.

The invention discloses a hybrid compensation filter cabinet in the field of reactive power compensation equipment of the power system. The hybrid compensation filter cabinet comprises a cabinet body.A dynamic filter reactive power compensation device and a static filter reactive power compensation device are arranged in the cabinet body; and each of the dynamic filter reactive power compensationdevice and the static filter reactive power compensation device consists of a controller, a change-over switch, a compensation capacitor bank, a fuse and a circuit breaker; and a current transformerand a voltage transformer are arranged between an external three-phase power grid and controllers of the dynamic filter reactive power compensation device and the static filter reactive power compensation device. Active power filters and the filter reactors are connected in series to the compensation capacitor banks of the dynamic filter reactive power compensation device and the static filter reactive power compensation device in sequence. Besides, a CPU processing module is arranged in the controller and includes a clock circuit and an energy storage module. The dynamic filter reactive powercompensation device and the static filter reactive power compensation device are connected in parallel with the external three-phase power grid. Therefore, harmonics in the power grid can be eliminated effectively; and the quality of the power grid is improved.

The invention relates to an automated testing system for testing bearing performance of an automobile. The automated testing system comprises a power supply, an upper computer, a motor driver and a motor, wherein the power supply is electrically connected with the upper computer, the motor driver and the motor separately; and the upper computer is electrically connected with the motor through themotor driver. According to the automated testing system, the upper computer issues system parameters and test tasks to the motor driver; and the motor driver drives the motor to run according to the system parameters and test tasks issued by the upper computer, thereby achieving automatic testing of the bearing performance. The automated testing system can meet the durability test conditions withhigher requirements; and compared with a traditional testing system for controlling a servo motor to test a bearing in a PLC pulsing mode, the automated testing system has the advantages that the testefficiency is greatly improved and the control accuracy on angles and torque is obviously improved.

The invention discloses a mems digital loudspeaker system and a working method thereof. The mems digital loudspeaker system comprises a DSP unit, a switching circuit, a driving unit and a mems loudspeaker array unit, wherein the DSP unit is provided with a digital audio signal and analog audio signal input port and eight digital signal output ports; the switching circuit and driving unit is composed of eight independent driving units; and the mems loudspeaker array unit is composed of 255 array elements. By arranging the DSP unit, the eight driving units and the mems loudspeaker array, very strong directional sound is generated, sound distortion can be effectively reduced, the DSP has a digital signal processing algorithm for audio to eliminate harmonic interference, and each driving unitis internally provided with a corresponding matching circuit to adjust sound pressure, so that the sound distortion is reduced, and by virtue of the high directivity of the ultrasonic waves, a sound directional propagation process is realized.

The invention relates to an automatic test system for clutch performance test. The automatic test system comprises a power supply, an upper computer, a motion controller, a motor driver and a motor; and the power supply is electrically connected with the upper computer, the motion controller, the motor driver and the motor respectively, and the upper computer is electrically connected with the motor through the motion controller and the motor driver in sequence. The upper computer issues system parameters and a test task to the motion controller, and the motion controller generates an electronic cam curve according to the system parameters issued by the upper computer and sends a motion control instruction to the motor driver according to the test task issued by the upper computer; and themotor driver receives the motion control instruction of the motion controller, and is used for driving the motor to operate according to the motion control instruction, so the automatic test system realizes automatic testing of clutch performance and can meet durability testing conditions with higher requirements, and the automatic test system greatly improves the testing efficiency and obviouslyimproves the testing frequency and the control precision of the angle and the torque.