Methods and apparatus for a variable resistor configured to compensate for non-linearities in a heating element circuit
US7002114B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 26, 2003 |
| Grant date | Feb 21, 2006 |
| Priority date | — |
| Expiry date | Aug 28, 2023 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG05D23/2401
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
An improved variable resistor at least partially compensates for non-linearities in an electrical circuit containing a heating element, for example, a thin-film heating element. A controllable heater includes a heating element, a voltage source (for example, a standard AC electrical outlet) coupled to the heating element, and a variable resistor coupled to the heating element and voltage source. The variable resistor includes a fixed resistive element (for example, one or more thin-film resistors) and a moveable element such as a slider control. The moveable element adjustably contacts the fixed resistive element at a contact point associated with the position such that the variable resistor has a resistance that is at least partially non-linearly related to the position, but wherein the heating element has a dissipated power that is at least partially linearly related to the position of the variable resistor. Such a system may be used in conjunction with a vapor-delivery device to provide more linear control over the intensity of fragrance provided within an environment.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.