Piezoelectric acoustic alarm
US6541894B1 · kind B1 · utility
1Cited by
11References
5Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Jun 3, 2002 |
| Grant date | Apr 1, 2003 |
| Priority date | — |
| Expiry date | Jun 3, 2022 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04R17/00
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
In a piezoelectric acoustic alarm piezoelements (2a, 2b) each excited by a square-wave voltage are arranged opposite each other in a resonance cavity (1) and each oscillate in opposing directions. The two square-wave voltages (Va, Vb) controlled by a microprocessor (8) are phase displaced by a square-wave pulse length and are positive or negative. A piezo-sound source designed and excited in this way is characterised by a high sound volume with low current consumption and small size.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.