Ultrasonic oscillation circuit
US4879528A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Aug 30, 1988 |
| Grant date | Nov 7, 1989 |
| Priority date | — |
| Expiry date | Aug 30, 2008 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB06B1/0253
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
A circuit for generating a driving signal for an ultrasonic vibrating element including a voltage controlled oscillator for generating an oscillation signal which is supplied to the ultrasonic vibrating element as the driving signal, a phase difference detector for detecting a phase difference between the voltage and the current of the driving signal to produce a control voltage corresponding to the detected phase difference, said control voltage being applied to a control input of the voltage controlled oscillator, a comparator for comparing the control voltage from the phase difference detector with a reference voltage to generate an output signal when the control voltage exceeds the reference voltage, and a voltage setter for responding to the output signal to reset the oscillation frequency of the voltage controlled oscillator to a predetermined frequency which is lower than the optimum resonance frequency so that the ultrasonic vibrating element is energized in the most efficient manner.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.