36results about How to "Weak noise" patented technology

A slider is provided with projections. Each projection is formed with tapered surfaces. A casing is provided with concave portions having the same shape as the projections. During the return of an operating body, the slider ascends while being inclined, and the slider stands upright as the tapered surface of the projection and the tapered surface of the concave portion of the casing slide on each other. Then, each projection is fitted into the corresponding concave portion, thereby positioning the slider.

To provide a noise suppressing device which accurately suppresses weak electric field strength pulse noise.A band-limiting unit (5) band-limits a composite signal obtained by demodulating an FM baseband signal, to a frequency band equal to or lower than a predetermined frequency so as to output a monaural audio signal. A pulse detecting unit (62) which detects pulse noise in the audio signal outputted by the band-limiting unit (5). A pulse judging unit (63) judges that a detection result of the pulse detecting unit (62) is valid in the case where pulse noise is detected in the composite signal, at a position corresponding to the detected pulse noise. A pulse suppressing unit (64) suppresses the pulse noise detected in the audio signal, in the case where the pulse judging unit (63) judges that the detection result is valid. Specifically, the amplitude of the composite signal which is synchronized with the audio signal is compared with a threshold, and it is judged that the detection result is pulse noise in the case where the amplitude of the composite signal exceeds the threshold.

The invention provides an electromagnetic energy-saving concrete vibrator which comprises a vibration bar. The vibration bar comprises a shell and an internal structure, the internal structure comprises an electromagnetic bar extending along the axis of the vibration bar, the electromagnetic bar is formed by connecting two or more segments of electromagnets in series, the segments of electromagnets are isolated through non-magnetism substance and are fixed, and the electromagnets are coupled with the same control module; one end of the electromagnetic bar is an end A, the other end of the electromagnetic bar is an end B, and the electromagnets are powered on circularly and alternately in a reciprocating mode through the control module from the end A to the end B of the electromagnetic bar first, then from the end B to the end A and finally from the end A to the end B; the control module is electrically connected with an external cable, the electromagnetic bar is surrounded by a spiral tube composed of non-iron magnetic substance, the two ends of the spiral tube are closed, a steel ball is arranged in the spiral tube, and the spiral tube and the electromagnetic bar are fixed to the shell. The vibrator is low in cost, small in energy consumption, low in noise and good in vibrating effect.

The invention aims to provide an internal-rotation vertical type bionic drag-reducing testing experiment platform which comprises a pool, a torque signal coupler, a device base, a device frame, and a rotary drum, wherein a liquid is filled in the pool, the device frame is arranged in the pool and is of a non-closed structure, the device base is fixed on the device frame, a water distributing sealing cavity and a device cavity are fixed on the device frame, the water distributing sealing cavity is located in the device cavity, a frequency modulation motor is fixed on the device cavity, the torque signal coupler is installed on the inner wall of the device cavity through a signal coupler base, the frequency modulation motor is connected with the torque signal coupler through an elastic pin coupler, a water distributing hollow shaft is arranged in the water distributing sealing cavity, the upper end of the water distributing hollow shaft is connected with the torque signal coupler through a plum blossom coupler, the lower end of the water distributing hollow shaft is connected with the rotary cylinder, the rotary cylinder is arranged in the device frame, a water pump is communicated with the pool through a first water pipe, and the water pump is communicated with the water distributing sealing cavity through a second water pipe. The internal-rotation vertical type bionic drag-reducing testing experiment platform is small in volume, simple in structure and convenient to operate.