7results about How to "Reduce high frequency noise" patented technology

This utility model relates to the field of pipeline technology, specifically to a compressor venting and noise reduction pipeline and its noise reduction system. The compressor venting and noise reduction pipeline includes: an exhaust pipeline, a bend downstream of the exhaust pipeline, a branch pipeline downstream of the bend, an output pipeline downstream of the branch pipeline, and a silencer downstream of the output pipeline. The silencer includes a spiral flow guiding device. This utility model reduces the velocity of the medium flow by using the bend, branch pipeline, and silencer, consuming part of the kinetic energy of the medium flow, thereby reducing the noise generated by the medium colliding with the pipe wall during discharge and reducing the safety risks to on-site personnel.

This utility model discloses a sound absorption and noise reduction structure for a vacuum cleaner, including an airflow channel pipe. One end of the airflow channel pipe is snapped into a vacuum cleaner connector. Dust chamber shell one and dust chamber shell two are respectively attached to both sides of the airflow channel pipe. The mating surfaces of dust chamber shell one and dust chamber shell two are snapped into each other, and a handle ring is snapped into the outer side of the dust chamber shell one near the vacuum cleaner connector end, and a limit ring is snapped into the outer side of the dust chamber shell one away from the handle ring end. A dust chamber shell cover is snapped into the top of dust chamber shell one and dust chamber shell two. Heat dissipation holes are opened on the bottom side of each dust chamber shell one and dust chamber shell two, and a motor assembly is fixedly connected inside the corresponding heat dissipation holes. Through the integrated design of airflow channel optimization, vibration isolation, composite noise reduction and efficient heat dissipation, the acoustic performance of the vacuum cleaner is improved while ensuring heat dissipation efficiency and structural reliability, achieving a comprehensive technical effect of low noise and high stability.

This application provides a single-sided detection system and vehicle. The single-sided detection system includes a voltage divider circuit, an amplifier circuit, an isolation circuit, an output circuit, and a controller. The voltage divider circuit divides the voltage of the high-voltage DC bus to obtain a first output voltage. The amplifier circuit is connected to the voltage divider circuit. The isolation circuit is connected to both the amplifier circuit and the voltage divider circuit. The output circuit includes a first operational amplifier and a first resistor. The inverting input terminal of the first operational amplifier and one end of the first resistor are connected to the fifth terminal of the isolation circuit, and the non-inverting input terminal of the first operational amplifier is connected to the sixth terminal of the isolation circuit. The first operational amplifier generates a second output voltage. The controller determines the voltage of the high-voltage DC bus based on the second output voltage. This single-sided detection system can isolate and monitor the voltage of the high-voltage DC bus, promptly detect voltage anomalies, and, with the isolation circuit, provides a high level of overall system safety.

The utility model relates to the technical field of stamping dies, in particular to a noise reduction type automobile stamping die and a control method.The noise reduction type automobile stamping die comprises a base, a die table is fixedly installed above the base, a die groove is formed in the upper end of the die table, a channel is formed in the lower end of the die table, and first air cylinders symmetrically distributed along the base are arranged in the channel; the lower end of the first air cylinder is fixed to the surface of the base through a screw, and a first piston rod for stretching is arranged in the first air cylinder. According to the scheme, wide-frequency-band noise control is achieved through the design of the five-layer composite sound insulation cover, the core innovation is that the synergistic effect of the array type rubber sound insulation columns and layered materials is achieved, the hollow structures of the sound insulation columns are combined with the rubber damping characteristic, 500-2000 Hz high-frequency noise can be attenuated in a targeted mode, and the impedance gradient design of the polyurethane foam reinforcing layer and the sound insulation cotton layer can achieve the purpose of noise reduction. And the die adopts a two-way limiting mechanism and a double-cylinder driving design, so that the accurate matching of a die head and a die groove is ensured, and the repeated positioning accuracy of stamping is high.

This application provides a headphone sound transmission device and a headphone. The headphone sound transmission device includes a sound transmitting element and a sound receiving element; the sound transmitting element has a first sound transmission channel and a second sound transmission channel that are interconnected, forming a sound transmission angle between the first and second sound transmission channels. The first sound transmission channel is connected to the inlet of the sound transmitting element, and the second sound transmission channel is connected to the outlet of the sound transmitting element. The sound receiving element is connected to the sound transmitting element and has a sound receiving port that is connected to the outlet of the sound transmitting element. When sound enters the sound transmitting element, it passes through the first and second sound transmission channels in sequence. The first and second sound transmission channels intersect each other, which attenuates and blocks high-frequency noise signals in the sound signal, thus reducing the high-frequency noise in the incoming sound and effectively improving the noise reduction capability against external noise.

The utility model relates to a kind of exhaust muffler of power supply vehicle and power supply vehicle, first turnover cover and second turnover cover are respectively set in the two sides of exhaust port, the bottom of first turnover cover and second turnover cover is respectively hinged with the carriage of power supply vehicle;Two first flow guides are respectively located in the inside of the other two sides of exhaust port, two first flow guides are respectively connected with the left and right sides of first turnover cover;Two second flow guides are respectively located in the inside of the other two sides of exhaust port, two second flow guides are respectively connected with the left and right sides of second turnover cover, two second flow guides are respectively located in the inside of two first flow guides;First turnover mechanism is used to turn over first turnover cover and two first flow guides up and down, to open or close exhaust port;Second turnover mechanism is used to turn over second turnover cover and two second flow guides up and down, to open or close exhaust port.When working, form the exhaust passage that is closed in all directions upward, reduce noise, reduce the influence to surrounding environment.

This utility model discloses an electromagnetic interference-resistant end cover for an automotive lock motor, comprising an end cover body, a thermal protector, a varistor, an inductor, a first carbon brush, a second carbon brush, a positive terminal, and a negative terminal. The first carbon brush is connected to one end of the thermal protector via a first conductive terminal, and the other end of the thermal protector is connected to the positive terminal. The second carbon brush is connected to one end of the inductor via a second conductive terminal, and the other end of the inductor is connected to the negative terminal. A first capacitor is connected between the first and second conductive terminals. The thermal protector of this utility model can automatically cut off the current when the motor is overloaded or the temperature is too high, preventing motor damage. The inductor can suppress electromagnetic interference, smoothing the current during frequent motor starts and stops and high-speed operation, thereby attenuating electromagnetic emission and radiation interference. The first and second capacitors filter out high-frequency noise and reduce current fluctuations, thereby effectively attenuating impedance-conducted interference. The overall structural layout is reasonable, effectively improving the electromagnetic compatibility and stability of the motor.