Ultrasonic horn driving apparatus and method with active frequency tracking
US4687962A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Dec 15, 1986 |
| Grant date | Aug 18, 1987 |
| Priority date | — |
| Expiry date | Dec 15, 2006 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB06B1/0261
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
The actual resonant frequency of an ultrasonic horn is tracked actively while the horn is operating in a working environment, such as in a clinical analyzer where the horn is partly immersed in a liquid bath in which a series of liquid-filled cuvettes are passed near the horn to dissolve solid tablets in the cuvettes. The horn is driven initially by a signal of fixed amplitude but at a frequency which is varied between set limits about a nominal resonant frequency. Ultrasonic vibration waves of the horn are sensed and fed back for rectification and peak detection over the scan operation. The peak feed back level is held and a second scan is initiated with the drive signal at the same fixed amplitude. When the rectified feedback signal level substantially attains that of the held peak level, a comparison is determined and control logic acts to lock on the frequency at which the comparison was established for a given operating time period.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.