| 摘要 |
PURPOSE: A resonance noise removing apparatus for dust separator using ultrasonic wave is provided to remove resonance noise by controlling the resonance forming time of ultrasonic wave at the ultrasonic wave generating circuit, without changing the structure of ultrasonic vibrator. CONSTITUTION: An apparatus comprises a frequency generating unit(31); a drive unit(32) for driving the frequency generated from the frequency generating unit; a switching power amplifying unit(33) for switching and amplifying the frequency driven by the drive unit; an impedance matching unit(34) for impedance matching the output from the switching power amplifying unit; an ultrasonic vibrator(35) for taking, as an input, the matched output from the impedance matching unit, and generating an ultrasonic wave by converting the electric signal into an ultrasonic wave; a phase detection and alarm unit(36) for receiving ultrasonic wave generated from the ultrasonic vibrator, detecting phases, and generating alarm upon occurrence of abnormality; and a control unit(37) for taking, as an input, the signal of the ultrasonic vibrator from the phase detection and alarm unit, and removing the resonance noise by periodically turning on/off the ultrasonic wave during a predetermined time period by controlling the drive unit in accordance with the resonance of the ultrasonic wave.
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