Patent ID: 7475495
Filing Date: 2009-01-13
Classification: D06F

Abstract:
1. A dryness sensing device for use in a laundry drying appliance comprising: two closely spaced electrically conductive dryness sensor bars, inside the drying appliance so that articles which are to be dried inside the drying appliance can contact both of the sensor bars at the same time; a current mirror configured to provide constant electrical current; the sensor bars being electrically connected between the current mirror an electrical ground; and a microcontroller electrically connected between the current mirror and the electrical ground, the microcontroller taking a measurement of a voltage across the sensor bars when the sensor bars are contacted by articles being dried, the microcontroller further determining the dryness of the articles being dried in the drying appliance by calculating an electrical resistance of the articles by dividing a value for the measured voltage across the sensor bars by a value for the constant electrical current through the sensor bars.