4results about How to "Eliminate howling" patented technology

The application discloses a kind of full-automatic hardware intervention method and device of pulse width modulation signal, method includes: S1, the extreme point of triangular carrier signal is set as absolute center;S2, by bottom hardware logic gate, an absolute symmetrical time execution window is automatically demarcated to two sides of absolute center;S3, when the count value enters time execution window, bottom hardware logic gate is configured to ignore current main duty cycle setting and carry out forced operation, for the level of PWM output channel is set or cleared;S4, carry out hardware level automatic flip: in successive PWM period, carry out hardware level automatic flip, for in fundamental center seamless superimposed alternating high-frequency square wave signal.The application introduces independent physical execution window and polarity automatic flip mechanism in the bottom digital logic of microcontroller timer, realizes high-frequency alternating voltage injection and accurate waveform clipping under zero CPU computing power consumption, completely eliminates phase distortion and risk of magnetic bias.

This invention relates to the field of microphones and discloses a microphone vibration reduction and noise reduction structure, which includes a body component and a connecting component. The body component includes a microphone assembly consisting of an upper microphone head and a lower microphone head, and a connecting frame located below the upper microphone head. The connecting frame has multiple protrusions arranged in a circular array inside. The connecting component includes a groove formed on the outer side of each protrusion. The bottom end of the lower microphone head is located inside the connecting frame, and its outer periphery is provided with multiple protrusions that are adapted to the grooves, allowing the two to be connected with a clearance fit. A stabilizing mechanism is also provided between the connecting frame and the lower microphone head for further stabilizing the microphone assembly. In this invention, firstly, the connecting frame engages with the connecting frame through the action of the grooves and protrusions, so that the lower microphone head engages with the connecting frame, while the upper microphone head does not contact the connecting frame. In addition, under the action of the stabilizing mechanism, the two can be further stabilized after the connecting frame and the lower microphone head are engaged, preventing the microphone assembly from vibrating, thereby eliminating the problems of feedback and hand noise.

The application discloses a PP material air-cooled extruder for cable insulation layer extrusion, and belongs to the technical field of plastic recycling and processing, which comprises a fixing base, the top end of the fixing base is provided with an extrusion mechanism, the extrusion mechanism comprises a conveying pipeline fixedly installed at the top end of the fixing base, a plurality of material guiding assemblies are fixedly installed inside the conveying pipeline, the material guiding assemblies comprise a plurality of extrusion pipe bodies for conveying PP materials and arranged inside the conveying pipeline, and the outer surface of the conveying pipeline is provided with a cooling mechanism. The buffering pressure relief cavity is arranged on the wall of the extrusion pipe body, and the air pressure linkage structure is formed by cooperating with a sliding block and a spring. The air cooling amount can be automatically controlled according to the cold air pressure, intermittent self-adaptive cooling is realized, and meanwhile, the global air cooling system is formed by matching the inner-outer combined cold air pipe, the problems of local supercooling and cooling dead angle are effectively avoided, the cooling rate of the PP molten material is uniform and stable, and the defects of cable insulation layer warping, eccentricity and excessive internal stress are reduced.

A window frame for a windshield of a civil aircraft and a civil aircraft including the window frame can reduce the number of fasteners or connectors used while enabling a force transmission path to be more continuous, thereby improving the overall load bearing performance. The window frame comprises a first opening frame and a second opening frame which are used for installing and fixing the windshield, the first opening frame and the second opening frame are adjacently arranged in the transverse direction of the civil aircraft, and the civil aircraft is characterized in that the first opening frame and the second opening frame are integrally formed.