Electronic washer control including automatic load size determination,

Abstract

A fabric washing machine has a container for fabrics and fluid to wash the fabrics. A switched reluctance motor is connected to the container. The motor is operated at a constant torque and the time needed to accelerate the container and a load of fabrics from one speed to a higher speed is measured. The measurement may be repeated with a different torque input. The inertia of the system, and thus the size of the fabric load, is calculated from the time measurement. The load size information, whether calculated or inputted, is used to calculate the blend of fabrics in the load. Water is added to the container in predetermined increments, and the container is oscillated a predetermined number of strokes and the required torque is measured after each addition of water. The required torque is used to calculate the blend of fabrics as the torque value varies with load size (already known) and the percentage of cotton in the load. An operation control includes a memory storing a number of set of values representing motor velocities and corresponding to particular load sizes and blends. The control calls up values from the set corresponding to the size and blend of the fabric load in the machine.