Microprocessor based control circuit for washing appliances

A control circuit for a washing appliance having electro-mechanical means for filling, circulating, and draining water in said appliance, which permits the user to select a plurality of operating cycles;

• said circuit comprising:
• (a) means for controlling said electro-mechanical means;
• (b) input means permitting user selection of desired operating cycles and including means for communicating with said control means to permit said control means to determine the cycles selected by the user and to control said electro-mechanical means in accordance therewith;
• (c) drain feedback means for detecting an operating condition of said drain means and producing an electrical signal indicative thereof, said operating condition being initiated by said electro-mechanical means for draining, said control means including means responsive to said electrical signal for detecting and distinguishing among a plurality of malfunctions in the operation of said drain means and effecting a change in the operating cycle if necessary to prevent water overflow or damage to the appliance;
• and means responsive to said electrical signal for timing the duration of said operating condition, determining the time difference between said duration and a reference, allocating this time difference to a subsequent user selected cycle when said duration is within said reference, and advancing to the next user selected cycle.