Electrical resistance element and use of this resistance element in a current limiter
US5602520A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 18, 1994 |
| Grant date | Feb 11, 1997 |
| Priority date | — |
| Expiry date | Aug 18, 2014 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01C7/13
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
The electrical resistance element (10) includes a resistance body (3), which is arranged between two plane-parallel, pressurized electrodes (1, 2), has PTC behavior and comprises a polymer matrix and two filler components of electrically conducting particles embedded into the polymer matrix (4). When a short-circuit current occurs, the resistivity of the resistance body (3) changes abruptly above a temperature limit value in a surface layer resting on the electrodes and containing at least a first of the two filler components. A second of the two filler components is selected such that a composite material containing at least the polymer matrix and the second filler component has PTC behavior, with an abruptly changing behavior greater by at least one order of magnitude in comparison with the surface layer. At the same time, this composite material has a resistivity which is lower by at least one order of magnitude than a composite material formed by the polymer matrix and the first filler component. The resistance element has a high nominal current carrying capacity and can limit large short-circuit currents permanently.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.