Method for controlling the lye pumping-off operation in washing machines

摘要

Method for controlling the lye pumping-off operation in washing machines. The lye-pump feed is to be matched to the quantity of waste spinning water occurring. Appliances available on the market control the lye pump via permanently predetermined time profiles by means of a programme-switching unit. The "on" and "off" times of the lye-pump are not synchronous with the quantity of waste spinning water, so that the idling pump sucks up air and does not transport the lye away. As a result of the solution according to the invention, the lye-pump feed is matched exactly to the quantity of waste water occurring. The current consumption of the drive motor (8) is monitored constantly and is fed as an input signal (11) to electronics (10). Desired values corresponding to the current consumption of a full-feed lye-pump (5) are stored in the electronics (10). By means of an actual/desired value comparison, the electronics (10) decide whether, via an output signal (12), the drive motor (8) is briefly switched off intermittently during idling and remains switched on during full feed. The method is suitable for domestic washing machines which have lye-pumps driven by synchronous motor. Moreover, it can be used in dishwashers having the same lye-pump drive motors. <IMAGE>