The Piezoelectric Demonstrator apparatus consists of a piezoelectric cell mounted in a retainer that allows axial pressure to be applied through a pushpin on a cam and lever. When the cell is compressed by rotating the lever, many thousands of volts are created across the crystal, enough to jump a gap of up to a ¼ inch. The output at each end of the cell is connected by wires to an adjustable spark-gap. The electrodes can be arranged with small balls or sharp points opposite one another. This will show the variation in the breakdown voltage of air depending on the geometry of the electrodes. When the lever is returned to level and the pressure across the cell is released, another spark, this time of reverse polarity, will be generated as the cell returns itself to neutral. This is an example of the direct conversion of energy from one form to another - in this case, from mechanical to electrical.
For those who wish to experiment in other ways with a piezoelectric device the mounted cell is available separately as GS-711.
Apparatus dimensions are 12.5x33cm. Cell dimensions are θ12mm x 60mm.
Instructions for Piezoelectric Demonstrator & Cell
Forensics Lab Supply Number 3178710.
Formerly Grau-Hall Corporation dba Grau-Hall Scientific.
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