摘要:
An apparatus for reducing noise for an interior of enclosed space, e.g., a vehicular compartment using an FIR adaptive digital filter is disclosed in which a control circuit is provided which outputs drive signals to a plurality of loud speakers which generate control sounds to interfer with a noise sound propagated in the interior so that a performance function including terms of residual noise signals output from residual noise signal detecting microphones and drive signals to the loud speakers is minimized and contributivity of the drive signals to the performance function is changed according to an occurrence of divergence in the noise reducing apparatus.
摘要:
A method for electrically attenuating a noise in an area for a sound wave to be propagatable in a three dimensional direction by making up a drive signal from the information on the noise and previously given filter coefficients by use of an adaptive digital filter and then generating an additional sound wave in accordance with the drive signal for cancellation of the noise. In the electric noise attenuation method, there are provided in a given region for noise attenuation, first and second error sensor groups for detecting an interference sound wave produced between the noise and additional sound wave, at a sampling time, a filter coefficient is calculated based on the information relating to the first error sensor group, at the next sampling time, another filter coefficient is calculated based on the information relating to the second error sensor group, and these operations are repeatedly executed sequentially for each error sensor to thereby update the filter coefficient of the adaptive digital filter.
摘要:
An automatic sound suppression system is automatically disengaged whenever noise in an area and generated counter noise deviate in their reverse phase relationship or if the amplitude of the counter noise deviates from that of the noise. The system can also be automatically disengaged whenever divergence prediction means predicts that sounds of the noise and the counter noise diverge or whenever divergence prediction means predict that sounds of the noise and the counter noise are about to diverge. The system can also operate as a vibration reducing apparatus which is also automatically disengaged whenever divergence prediction means predicts that a vibration and a generated countervibration diverge.
摘要:
A swash plate type compressor including a partition plate mounted in a side cover for axially partitioning the interior of the side cover into two portions. One of said two portions interposed between the partition plate and a valve plate functions as a high pressure chamber, and the other portion interposed between the partition wall and a bottom wall surface of the cover functions as a silencing chamber. A compressed refrigerant discharged from cylinder bores and introduced into the high pressure chamber is discharged from the high pressure chamber through the partition plate into the silencing chamber where pulsations of pressure are removed from the refrigerant.By directing the compressed refrigerant discharged from the high pressure chamber toward the center of the silencing chamber and by drawing off the refrigerant from the center of the silencing chamber and introducing same into the refrigerant cycle, increased effects can be achieved in silencing noises.
摘要:
An easy-to-use remote keyless entry system is provided. To execute 2-way long distance communication at a low output and within a short time, transmission is effected while a data rate of a terminal board is changed. To reduce battery consumption in a system capable of setting an automatic output mode, the operation mode is shifted to the automatic output mode when an automatic output mode button is pushed or when a door lock release button of an operation button, etc, is kept pushed for a predetermined time. To execute a reserved operation at a reserved time, a storage circuit for storing reservation is provided to the terminal board.
摘要:
An easy-to-use remote keyless entry system is provided. To execute 2-way long distance communication at a low output and within a short time, transmission is effected while a data rate of a terminal board is changed. To reduce battery consumption in a system capable of setting an automatic output mode, the operation mode is shifted to the automatic output mode when an automatic output mode button is pushed or when a door lock release button of an operation button, etc, is kept pushed for a predetermined time. To execute a reserved operation at a reserved time, a storage circuit for storing reservation is provided to the terminal board.
摘要:
A capacity control device for a compressor used with an air conditioning system for an automotive vehicle and driven by an engine of the automotive vehicle, including flow resistance portions provided in a refrigerant inlet passage and capable of reducing the flow rate of a refrigerant flowing into working chambers of the compressor as the rotational speed of the compressor (or the engine speed) rises, to thereby reduce the volumetric efficiency of the compressor in a high engine speed range.
摘要:
In a method of adjusting the axis of a car on-board radar, especially, a car on-board mono-pulse radar having the function of transmitting radio waves, light or ultrasonic waves, a car axis and an offset axis are set and the mount angle of an antenna offset-mounted on the offset axis can be adjusted with high precision and with ease through a reduced number of process steps. In the method, at least two points are set on the car, at least two isosceles triangles having a common base defined by a line connecting the setting points and sides of different lengths are drawn, a line connecting vertexes on the same plane of the obtained isosceles triangles and an extension of that line are determined as the car axis, the radar antenna is mounted on the car at an offset position which is apart from the car axis by a constant distance in the horizontal direction, a straight line parallel to the car axis and passing through the offset position is determined as the offset axis, a reflector is disposed in a direction at a constant azimuth angle as viewed from the offset position of the antenna, and the reflector is used as a detection target of the radar to adjust the mount angle of the radar antenna such that an azimuth angle detection value of the reflector detected by the radar equals a setting value of the azimuth angle.
摘要:
When noise is caused by the mechanical vibration propagated from the engine, the microprocessor calculates from the vibration frequency of the engine the secondary sound signal which is in antiphase with the noise and which is thus able to cancel out the noise, and supplies it to the loudspeaker which then emanates the secondary sound according to this signal. At this time,the divergence detection circuit monitors the incoming secondary sound signal, and when the secondary sound signal is remarkably increased, it decides that the noise is increased, and automatically stops the secondary sound output from the loudspeaker. Therefore, it can be prevented that the noise is reversely increased by the secondary sound.