Method and apparatus for controlling ultrasonic transducer
US6819027B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Mar 4, 2002 |
| Grant date | Nov 16, 2004 |
| Priority date | — |
| Expiry date | Jun 11, 2022 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB06B1/0261
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
Method and apparatus for implementing ultrasonic systems that maximize efficiency by dynamically detecting and maintaining peak operational resonance frequency. In one embodiment, the invention dynamically sweeps the output frequency range to locate the peak load current. The resonance frequency corresponding to the peak load current is used as a reference frequency in a control loop. The control loop includes a voltage-controlled oscillator (VCO) that is controlled by a loop controller and operates to lock onto the dynamically sensed reference frequency. In response to the VCO output, a pulse-width modulator (PWM) circuit drives a pair of switches that adjust transducer current to maintain the circuit locked on the resonance frequency at a substantially constant current.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.