A Driver for Piezoelectric Transducers with Control of Resonance

Abstract

Variations in electric impedance curves of piezoeletric transducers occur under influence of mechanical load, temperature, electric excitation, among others. Electronic circuits for driving these transducers should correct the tune to maintain the performance of the transducer. Considering the changes at resonance, we have developed a circuit for a laboratory bench that performs two functions. The first, working on low power, by swapping frequencies around resonance, allows to the user define electric impedance and frequency operation that intend to apply in the experiment. The operation of this circuit is based on detection of magnitude of current in the transducer. A microcontroller and Labview are used to obtain the results. In the second, while under high power operation, deviations from original impedance are corrected by using a feedback network that evaluates amplitude of impedance. In this circuit, a class D MOSFET amplifier is used for exciting the transducer. Also, a microcontroller system controls the feedback network. Experiments with variation of mechanical loads have shown the effectiveness of the system.

[1929] Uma Abordagem Didática Para O Estudo De Amplificadores Eletrônicos

“…Do ponto de vista prático, significa que as amplitudes de vibração também seriam reduzidas fazendo com que o sistema acústico deixe de operar em sua plenitude. Como essas variações de R1 e C1 são consequências de efeitos externos ao circuito eletrônico excitador, muitas vezes é empregado um sistema PLL (Phase-Locked Loop) (RAMOS-FERNANDEZ; MONTOYA-VITINI; GALLEGO-JUAREZ, 1985;ARNOLD et al, 2015) que corrige a frequência de excitação do transdutor. As potências de dissipação dos transistores, média e máxima, são mostradas nas Figuras 11 e 12, respectivamente.…”

Wide temperature operation of piezoelectric sensors for detecting precursor levels in a canister

“…The optimization of driving piezoelectric devices is a central issue in developing end-user applications. Significantly, optimization of operation frequency is crucial to minimize the energy loss during the electrical driving [13][14][15][16] and maximize the signal-to-noise ratio (SNR) in sensing the mechanical waves [12,17]. However, the previous works overlooked the critical fact that the resonance frequency of the piezoelectric devices is susceptible to environmental temperature.…”