Article Contents

1. Introduction
2. FM: Sweep and Dual Sweep
3. Ultrasonic Power Into a Tank
4. FM: Upsweep
5. Multiple Frequencies (1)
6. Multiple Frequencies (2)
7. Cavitation
8. Transducer Impedence (1)
9. Transducer Impedence (2)
10. Transducer Impedence (3)
11. Universal Transducer
12. Applying the Technology (1)
13. Applying the Technology (2)
14. Applying the Technology (3)
15. Conclusion

Designer Waveforms: Ultrasonic Technologies to Improve Cleaning and Eliminate Damage
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There are many ways to alter the characteristics of ultrasonic waves in a liquid contained in a tank. The ultrasonic waves can be frequency modulated (FM) by varying the output frequency of the ultrasonic generator. The ultrasonic waves can be amplitude modulated (AM) by changing the amplitude of the generator output and/or by tailoring the impedance versus frequency characteristics of the transducer array. A frequency modulated ultrasonic wave can be amplitude modulated. This is the most general case of "designer waveform" for a single generator driving a single transducer array. Multiple generators of different frequencies can drive multiple transducer arrays on the same tank; the addition of the resulting sound waves within the liquid creates the "designer waveform".

This article will attempt to catalog the most useful, newest and theoretically interesting of the many ultrasonic waveforms that can be produced in an ultrasonic tank. Where appropriate it will give the history of the waveform, a practical description of its function and suggestions of where it may be advantageous, or in some cases, destructive. Empirical data supporting the theory is left for a future article.

Before starting the body of this article, we would like to give credit to inventors such as Antonevich, Branson, Cook, Puskas, Honda, Kosaka, Kouzaka, Ferrell, Thompson, Miyamoto, Goodson, Shibano, Saito, Quint and Pedziwiatr who have patents issued or pending that describe some of the concepts presented below.

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