SOI/DT 2007-02 dmm
50/66
599 38 61-92
9.3
Water fill system
The electric valves are powered by the PCB by means of the triac and the control of the water level in the tub is
carried out by the analogue pressure switch.
3 Analogue
pressure
switch
5
Prewash electric valve
6
Wash electric valve
7
Bleach electric valve
20 PCB
9.4
Analogue pressure switch of water level control in the tub
General features
The electronic pressure switch is an analogue device that controls the water level in the tub, used in the models
with electronic control and it is directly connected to the main PCB.
ELECTRONIC PRESSURE SWITCH
Electronic pressure switch
Electric symbol
The pressure switch is connected by a hose to the pressure chamber.
When the tub is filled with water, the pressure created inside the hydraulic circuit expands the diaphragm. This
in turn modifies the position of the core inside the coil, thus changing the inductance and the frequency of the
oscillating circuit.
The electronic PCB, according to the frequency, recognizes the quantity of the water in the tub.
1 hose
3 coil
5 core
Frequency variation according to the water quantity in the tub
