Patent ID: 6163017
Filing Date: 2000-12-19
Classification: F25D,G05B,G05D

Abstract:
A device for controlling a physical quantity, such as temperature or humidity, which is set by a user in a household electrical appliance such as an oven, a refrigerator or a washing-drying machine, said device comprising:at least one measuring member for measuring the physical quantity,an electrical signal generator means connected to the measuring member, the at least one measuring member feeding an electrical signal (A1) corresponding to the value of the measured quantity to the electrical signal generator means, the signal generated by said signal generator means being proportional to the value of the measured physical quantity,a control means operatively connected to said measuring member, said electrical signal emitted by said signal generator means being fed to the control means,regulating means for regulating the physical quantity, the regulating means being operatively connected to the control means,wherein said control means measures the ON and OFF period of the electrical signal emitted by said signal generator means and on the basis of the ratio of the ON and OFF period evaluates and measures a finite value of the physical quantity, said finite value then being compared with a reference value set by the user, the control means acting on the regulating means for the controlled quantity such that the value of the measured quantity is made equal to and/or maintained at the set value.