Abstract: An ultrasonic electro-mechanical resonant system and instrument that provides improvements in the design and implementation of a feedback system. The disclosed configuration and orientation of coils enhance the motional or velocity feedback signals while minimizing the effects of transformer coupling. A two coil and a three coil approach is disclosed that takes advantage of non-homogeneous magnetic fields. An asymmetrical arrangement enables velocity signals to be coupled into the coils without requiring additional signal conditioning or capacitive elements.
Type:
Application
Filed:
April 1, 2011
Publication date:
October 6, 2011
Applicant:
Paschke Consulting Group Inc. (PCG INC.)
Abstract: A magnetostrictive ultrasonic dental scaler is disclosed. The magnetostrictive device comprises an oscillator adapted to provide electrical energy including a current and a voltage signal, a handpiece having a tool tip which vibrates in response to the electrical energy supplied to the handpiece and a control circuit. The control circuit includes a phase detector adapted to detect phase between current and voltage signals and to generate a phase detection signal as a function of the phase. The control circuit also includes a digital signal processor operatively connected to the phase detector. The digital signal processor adapted to process the phase detection signal through a digital loop filter to generate an error signal.
Type:
Grant
Filed:
May 18, 2006
Date of Patent:
November 10, 2009
Assignee:
PCG, Inc.
Inventors:
Richard Paschke, Noel S. Paschke, Emery S. Rose