PTC heating wire
US4661690A · kind A · utility
8Cited by
7References
13Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Jun 21, 1985 |
| Grant date | Apr 28, 1987 |
| Priority date | — |
| Expiry date | Jun 21, 2005 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH05B3/14
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
This invention provides a PTC heating wire (12), (13) of a tubular or band form which comprises a pair of electrodes (2), (2'), a PTC resistor (3) provided between the electrodes, and an insulative sheath (4) covering the electrodes and resistor, in which a numerical formula for setting a resistance, R.sub.E, within a tolerance range including an optimum resistance value is first determined. In practice, the resistance, R.sub.E, of the electrodes (2), (2') is properly determined, according to use conditions, using the numerical formula, thereby obtaining a PTC heating wire which ensures safe service.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.