Jump phenomena of current in piezoelectric-ceramic vibrators under high power conditions

In order to investigate the origin of current-jump phenomenon when piezoele ctric-ceramic vibrators were driven at high power levels, the influence of higher harmonics due to the ferroelectric nonlinearity on the jump phenomen on was studied. Using the equivalent circuit equation including a higher ha rmonic term, the theoretical calculation was performed. Since the calculate d values of current under jump phenomena agree well with the measured ones, the jump phenomenon is due to the higher harmonics caused by ferroelectric nonlinearity. It was also found that the strain jump phenomenon appears wh en the jump of current occurs around the resonance frequency. (C) 1999 Else vier Science Limited. All rights reserved.