A low-cost alternative power supply for integrated electronic piezoelectric transducers

Comercial hardware compatible with IEPE precision sensors normally are expensive and often coupled to proprietary and expensive software packages. commercially available sound cards are a low cost option for AD, but are incompatible with IEPE sensors. To create 4 mA constant current for IEPE transducers commercial solutions are available and labs also have created such solutions, e.g., ITA at RWTH Aachen University. Unfortunately, commercially available circuits are still to expensive for large scale classroom use in Brazil and circuits created elsewhere contain parts subject to US export restrictions or require machines for creation of circuits. Thus, based on a previous project, a new low-cost prototype was mounted on phenolic board. The circuit was tested with an IEPE microphone connected to a commercial soundcard and ITA-Toolbox software and compared to a commercial hardware/software package. The results were very similar in the frequency range between 20 Hz and 10 kHz. The difference below 20 Hz prob...