Electric heating elements free of electromagnetic fields
US4998006A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Feb 23, 1990 |
| Grant date | Mar 5, 1991 |
| Priority date | — |
| Expiry date | Feb 23, 2010 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02B30/00
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
An electric heating element which includes two sets of adjacent electrically conductive wires electrically insulated from each other. By adjacent is meant that the two sets of wires are placed as close to each other as is possible without electrically connecting the two wires; for example, the wires are preferably within 2 to 4 millimeters of each other. One set of wires is constructed and arranged to carry electric current in a first direction through the heating element. The other set of wires is constructed and arranged in a parallel circuit to the first set to carry electric current in the opposite direction through the heating elements. At least one of the sets of wires is further constructed to generate heat when the electric current passes through that set of wires. Each set of wires in the heating element has equal impedance such that any magnetic field generated by one set of wires is reduced or eliminated by an opposing magnetic field generated by the other set.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.