The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 04, 1999
Filed:
Jun. 26, 1996
Lamar Heath Gipson, Acworth, GA (US);
Bernard Cohen, Berkeley Lake, GA (US);
Lee Kirby Jameson, Roswell, GA (US);
Other;
Abstract
An apparatus and method for controlling an ultrasonic transducer preferably including a signal generator circuit, a signal sensing circuit, a modulator circuit, and a bias circuit. The signal generator circuit provides a pulsed drive signal to the ultrasonic transducer. The signal sensing circuit senses the voltage and current of the drive signal. The modulator circuit provides a frequency control signal and an energy control signal to the signal generator circuit corresponding to a detected phase difference between the sensed voltage and the sensed current of the drive signal. The frequency control signal and energy control signal operate to adjust the frequency and energy level, respectively, of the drive signal. Within the transducer, a movable element in contact with a liquid is preferably positioned corresponding to the level of a dc bias signal provided by the bias circuit. By adjusting the level of the dc bias signal, the flow rate of the liquid is adjusted. By applying the drive signal to the transducer, the viscosity of the liquid is adjusted which establishes a second flow rate of the liquid. When the frequency and energy level of the drive signal are changed, a third flow rate of the liquid is established.