Heating-control isolation-diode temperature-compensation
US7746087B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 13, 2007 |
| Grant date | Jun 29, 2010 |
| Priority date | — |
| Expiry date | Dec 4, 2027 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01K2207/00
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A semiconductor integrated circuit (IC) acts as a controller of a heating-controlled device or appliance. A heating body has a positive temperature coefficient and acts as both a heating element and a temperature sensor. A Silicon-Controlled Rectifier (SCR) switches AC current to the heating body to increase its temperature. When the SCR switches off, temperature sensing is performed using a sampling resistor, isolation diode, voltage comparator, and switch for a low-voltage DC supply are formed on an integrated circuit that has a first circuit branch and a second circuit branch. A compensation diode and a compensation resistor can be added in parallel to reference resistors. The compensation diode compensates for the forward voltage drop of the isolation diode that would otherwise create an inaccurate temperature measurement. The diodes have the same temperature response, allowing for a more accurate temperature measurement over a full temperature range of the sensorless appliance.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.