Circuit protection devices
US4352083A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 21, 1980 |
| Grant date | Sep 28, 1982 |
| Priority date | — |
| Expiry date | Apr 21, 2000 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01C7/027
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
Circuit protection devices which comprise two columnar electrodes and a conductive polymer element, at least a part of which is a PTC element. The device is so constructed that if a hot zone forms in the PTC element when current is passed through the device, it forms at a location away from the electrodes, thus increasing the useful life of the device. In one preferred embodiment, the conductive polymer element has an intermediate portion of increased resistance, thus causing the hot zone to be located at or near the intermediate portion. The intermediate portion may be of reduced size and/or be composed of conductive polymer of relatively high resistivity.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.