Induction motor for loudspeaker
US8009857B2 · kind B2 · utility
9Cited by
9References
21Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Feb 15, 2007 |
| Grant date | Aug 30, 2011 |
| Priority date | — |
| Expiry date | Jul 1, 2030 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04R2209/043
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An audio loudspeaker having an induction motor whose yoke components are formed of powdered iron or other material which is highly magnetically permeable and highly electrically resistive. The oscillating magnetic flux caused by the alternating current applied to the primary coil induces eddy currents in the shorted turn secondary coil but not in the yoke components. This reduces heating of the yoke components, reduces flux modulation, and reduces wasted power.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.