Odobescu G., Odobescu R.

The paper presents a method to measure the power transfer from electric generators to high intensity piezoelectric transducers, when their acoustic load has any complex value. In fact, the transducers working in ultrasonic welding equipment, in ultrasonic cleaning systems or even in other technological installations, can not be considered as having at least a approximate constant charge. Instruments used to measure transferred power sound from electric generators to high intensity piezoelectric transducers are commercially available but they are extremely expensive. In addition, using “square law” multipliers makes the modern commercial instruments. But these works only over a limited range of power factor, which irrespective of cost, precludes their use with our system where the operating power factor could be overcome by using dynamometer-type instruments. But these do not lend themselves to recording transient changes in the measured parameter due to their poor frequency response. They also present difficulties in obtaining an electrical output proportional to the measured value. Using an integrated circuit multiplier, author has developed a wattmeter capable to measure active power in specific conditions of work for high intensity piezoelectric transducers: high currents and tensions, high phase difference between the current and the tension and frequency range [10-100] kHz. This mode of measurement is capable of measuring active power-W, reactive power-VAR and peak power-VA. Its power factor range and frequency response together with its cheapness has enabled this instrument to be used for assessment and measurements in high power ultrasound systems.