Maytag Corporation

The Maytag Company

Pamela M Kuecker

Michael D Lafrenz

Charles L Jackson

Gregory K Harmelink

J Christopher Millet

The proper adjustment of a potentiometer is achieved through the use of a software routine that detects the output frequency from a thermistor circuit and compares the detected frequency with a predetermined desired frequency. A control signal is sent to either an adjustment means or a display means or both. Thus, there is no need for external frequency meters eliminating the disadvantages associated therewith to properly adjust a potentiometer. The display means will activate the proper light emitting diodes such that said comparison is displayed. The shaft of the potentiometer can then either be turned manually or automatically in the correct direction and to the correct degree so that a proper adjustment is achieved.

Method and apparatus for the fine adjustment of a potentiometer

A microprocessor controlled clothes dryer wherein the posture of a switch in the lint filter system is monitored and a signal to CHECK FILTER is displayed if the switch posture has not changed. The switched is a reed switch mounted stationary on the lint filter assembly and a magnet operator is attached to the removable filter screen. Movement of the filter screen into and out of filtering position in the lint filter assembly of the exhaust duct changes the posture of the magnet operated reed switch. Change of posture of the switch through its cycle impresses a change of voltage on the microprocessor. The microprocessor effects control over the CHECK FILTER signal that is visually illuminated on a VFD tube; such that, if the microprocessor sees the cycling of the switch the CHECK FILTER signal is extinguished.

Lint filter signal for automatic clothes dryer

A fabric drying apparatus including a fabric tumbler is provided which includes control circuitry for interrupting a cycle upon detection of temperature signals outside a predetermined range. A power supply energizes the fabric drying apparatus. A heater is generally associated with the fabric tumbler for providing heated airflow thereto. Temperature sensing circuitry includes at least one thermostat for controlling the cyclic operation of the heater to provide airflow in a predetermined temperature range. The temperature sensing circuitry further includes oscillator circuitry operable to provide a frequency output variable in response to airflow temperature. A control system includes a microcontroller in communication with the oscillator circuitry, the cycle selection switches, the display system and the power supply. The microcontroller is operable for monitoring the temperature of the airflow through the frequency output of the oscillator circuit and for deenergizing the fabric drying apparatus and preventing reenergization thereof responsive to a frequency output outside a predetermined range. The frequency output outside of the predetermined range is indicative of a failure of the cycling thermostat or the thermistor circuitry and the microcontroller will effect the display of a coded message corresponding thereto in the display system.

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Prairie City, IA, United States of America

Pamela M Kuecker