Dynamic measurement techniques of contact pressure using piezoelectric PVDF film

The main purpose of this paper is to obtain the dynamic behavior of contact pressure on contacts using polyvinylidene fluoride (PVDF) piezoelectric film. Based on the pressure measurement principle of PVDF piezoelectric film, an AC contactor contact pressure sensor was developed whose sensitive elements were made of PVDF. The sensor's output was connected to a charge amplifier via shielding line to get voltage signal, which was proportionate to the contact pressure, and thus whose dynamic behavior was obtained. A distinct dynamic behavior of contact pressure was got from a dynamic testing on CJ20-25. The voltage waveform reflects the dynamic variation trend of the contacts contact pressure. It also indicates the changes of the peak contact pressure and contact bounce under different close phase angle. Previous AC contactor dynamic characteristics test system does not have this function. Finally the influence factors of sensitivity were discussed.