System for monitoring spray arm rotation of dishwasher - has each spray arm driven by reaction of rinsing liquid leaving spray arm nozzles and sensor detecting rotation

摘要

The vibrations produced by the spray arms (2) at the flushing container inner wall (6) and/or the door (6') are sensed. The thus obtained signal mixture is evaluated for identifying the spray arm rotation. An electrical signal is converted from the signal mixture consisting of the vibrations resulting at the flushing container inner wall (6) and/or the door (6'). Each spray arm (2) is assigned a characteristic frequency range (f1,f2,f3) from the frequency spectrum of the electrical signals. The signal components in this frequency range call uo amplitude modulating alternating signals, for identifying and indicating or not indicating the rotational movement of an individual spray arm (2). USE/ADVANTAGE - Method and system for monitoring spray arm rotation in dishwasher. The sensing of spray arm rotation is simplified, without need for auxiliary switch or control elements such as magnets or coils.