The ultrasonic power supply (generator) converts 50/60 Hz voltage to high frequency electrical energy.
This alternating voltage is applied to disc-shaped ceramic piezoelectric crystals within the converter, causing them to expand and contract with each change of polarity. These longitudinal vibrations are amplified by the probe (horn) and transmitted into the liquid as ultrasonic waves consisting of alternate expansions and compressions. The pressure fluctuations pull the liquid molecules apart creating micro-bubbles (cavities), which expand during the negative pressure excursions, and implode violently during the positive excursions. As the bubbles collapse, millions of shock waves, eddies and extremes in pressures and temperatures are generated at the implosion sites. Although this phenomenon, known as cavitation, lasts but a few microseconds, and the amount of energy released by each individual bubble is minimal, the cumulative amount of energy generated is extremely high. The high shear energy delivered is at maximum near the tip of the probe, and decreases as the distance away from the tip increases.
