US Patent 7475495 Dryness sensor for clothes dryer

The current invention relates to a clothes dryer having a dryness sensing device and method of use comprising at least two electrically conductive sensor bars placed closely together but not touching one another so that articles in the dryer can contact two of the sensor bars at the same time. At least one sensor bar is electrically connected to an electrical current source and at least one sensor bar is electrically connected to an electrical ground. A microcontroller is electrically connected between the electrical current source and the electrical ground so as to be capable of measuring the voltage across the sensor bars when the sensor bars are contacted by the articles being dried. The microcontroller is configured so as to determine the dryness of the articles by calculating the electrical resistance of the articles by using the value of the voltage across the sensor bars and the value of the current through the sensor bars.