Over-current protection device
US8446245B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 19, 2011 |
| Grant date | May 21, 2013 |
| Priority date | — |
| Expiry date | Jan 23, 2032 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01C7/027
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
An over-current protection device includes two metal foils and a PTC material layer laminated therebetween. The PTC material layer has a volume resistivity between 0.07 Ω-cm and 0.32 Ω-cm. The PTC material layer includes a crystalline polymer, a conductive ceramic carbide filler of a particle size between 0.1 μm and 50 μm and a volume resistivity less than 0.1 Ω-cm, and a carbon black filler. The weight ratio of the carbon black filler to the conductive ceramic carbide filler is between 1:90 and 1:4. The conductive ceramic carbide filler and the carbon black filler are dispersed in the crystalline polymer. The resistance ratio R100/Ri is between 3 and 20.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.