Fuse state indicator
US6566996B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 29, 2000 |
| Grant date | May 20, 2003 |
| Priority date | — |
| Expiry date | Mar 29, 2020 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01H85/30
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A fuse state indicator includes a fuse casing having a transparent lens, a combustible substance disposed adjacent the lens, and a base layer disposed adjacent the combustible substance and having a contrasting color relative to the combustible substance. A secondary fuse indicating circuit is electrically connected to a main fuse circuit in parallel with a main fuse link, and includes a secondary fuse wire link which is disposed adjacent the combustible substance. Heat created upon vaporization of the secondary fuse link ignites the combustible substance and reveals the base layer through the lens after combustion, thereby indicating a state of the fuse as operable or inoperable by the color visible through the lens. Combustion may be assisted with an energetic chemical compound applied to secondary fuse wire link and combustible substance.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.