Patent · US Expired

Automatic fire detection for a microwave oven

US4496817A · kind A · utility

16Cited by
15References
7Claims
0Family size

Assignee

Inventor

Key dates

Filing dateJul 7, 1983
Grant dateJan 29, 1985
Priority date
Expiry dateJul 7, 2003

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH05B6/666
  • WIPO fieldElectrical machinery, apparatus, energy
  • WIPO sectorElectrical engineering

Abstract

A method and apparatus for anticipating the occurrence of a fire in the cooking cavity of a microwave oven. The oven is provided with a blower for continuously circulating outside air through the cooking cavity to carry away gases by food loads being heated therein. A sensor responsive to the concentration of gases in the circulating air monitors the gas concentration level and generates an output signal representative thereof. Sensor monitoring circuitry responsive to the sensor output signal is operative to determine the rate of change of the gas concentration level, and a detect a characteristic rate of change indicative of the load being heated closely approaching its combustion point. Upon detection of the characteristic rate of change, power to the oven is turned off and and indication is provided to the user that a combustion condition in the oven cavity is imminent.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.