Water loss warning system for domestic washing machines - has two=way circuit interrupter to illuminate signal lamp or sonic alarm unit

摘要

The automatic warning system enables water loss system in a domestic washing machine to be signalled. The circuit arrangement incorporates a receiver electrode (1), a signal electrode (2) and a bipolar interrupter (6). Each of the limbs of the latter is in series with a line of differential resistance (23) each in turn being on series with one way of a two way switch (22) connected between the neutral and one phase of an AC supply. When the water level falls to a level which is too low, the switch (22) is closed and this illuminates a warning lamp (5) in the circuit. The base and screen system (3, 4) of the machine are connected to the earth line of the electric power circuit. The lamp may be replaced by a sonic alarm with a current consumption of less than 300 mA.