Apparatus for controlling an electric heater energized from a single voltage alternating current supply
US6118106A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Aug 21, 1998 |
| Grant date | Sep 12, 2000 |
| Priority date | — |
| Expiry date | Aug 21, 2018 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH05B3/74
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
Apparatus is described for controlling an electric heater incorporating at least one electric heating element (2A, 2B, 2C) and energized from a single voltage alternating current supply (8). The apparatus includes a control knob (15) for manually selecting any one of a predetermined number of power settings for the heater from the voltage supply (8), the power settings varying progressively between a minimum power setting and a maximum power setting. The apparatus further includes a controller (10) adapted and arranged to supply to the electric heater within a predetermined constant time interval in each power setting a first dissipated power level and a second dissipated power level. The first dissipated power level comprises a first selected proportion of half cycles in a predetermined number of half cycles of the voltage supply and the second dissipated power level comprises a second selected proportion of half cycles in a predetermined number of half cycles of the voltage supply. In a plurality of power settings the second selected proportion is different to the first selected proportion. There is no more than one change between the first and second dissipated power levels with…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.