We have previously succeeded in measuring the acoustic signal due to the dielectric barrier discharge and the dominant frequency components have been studied to discriminate the sound signal. We have been performed that the dominant frequency components appear over 20kHz of acoustic signal by the dielectric barrier discharge.
Recently surface discharge control technology has been focused from practical applications such as ozonizer, NOX reactors, light source or display. The fundamental experiments were carried to examine the creeping discharge using the acoustic signal. When the high voltage (6kV, f=10kHz: in use of continuous high frequency high voltage power supply) was applied to the electrode, the discharge current flew and the acoustic sound was generated. The current waveform was pulse-like, and it seemed to generate the creeping discharge. The current, voltage waveforms of creeping discharge and the sound signal detected by the condenser microphone were stored in the memory recorder.
In this scheme, Continuous Wavelet Transform (CWT) was applied to discriminate the acoustic sound of the micro discharge and the dominant frequency components were studied. CWT result of sound signal showed the frequency spectrum of wideband up to 150kHz. In addition, the energy distribution of acoustic signal was examined by CWT, when the discharge time was changed from 60ms to 100ms.
Moreover, we performed the measurement of the acoustic signal by the laser light diffraction effect between the ultrasonic wave and laser beam. This method is useful to measure the acoustic signal in the ultrasonic frequency domain.
The electric discharge sound may be considered the utilization of the monitor of the creeping discharge, the effective ozone generation and NOX reactors.
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