Piezoelectric audible alarm frequency self-calibration system
US4275388A · kind A · utility
11Cited by
4References
10Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Jan 9, 1980 |
| Grant date | Jun 23, 1981 |
| Priority date | — |
| Expiry date | Jan 9, 2000 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB06B2201/55
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
A piezoelectric transducer frequency self-calibration system interrogates the transducer by driving it with various frequencies within a specified range while monitoring the transducer output power level. Two threshold frequency points are identified at which the output power level is at a predetermined threshold level less than the expected maximum output level, and the average of these two threshold frequencies is taken to be the optimum frequency.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.