Development of Signal Conditioning Circuit for Piezoelectric Energy Harvester

Signal conditioning is critical in electronic measurements and instrumentation, particularly for piezoelectric energy harvesters (PEHs) that rely on precise and accurate signal conversion. The inherent electrical signals generated by PEH devices are typically small and can be easily obscured by noise or may not be in a suitable form for direct processing. Therefore, a charge amplifier, a fundamental signal conditioning component, was developed to address these challenges. Moreover, precision full wave rectifier was designed to convert generated alternating current (AC) voltage from the charge amplifier to direct current (DC) voltage. A polyvinylidene fluoride (PVDF) / polyethylene terephthalate (PET) PEH device was prepared and mounted on a specially designed holder. Vibration was applied to this device using an electromagnetic shaker, and its resonance frequency and output voltage were monitored and observed using a digital signal analyser (DSA). Additionally, the integration of this circuit with the PVDF/PET device was presented in this work. The output of the PVDF/PET device was amplified by a charge amplifier from 2.12V peak-to-peak to 4.16V peak-to-peak and then converted to a 2.08V peak-to-peak DC voltage by the precision full-wave rectifier.