Operating Principle Of The Flowmeter - Electrolux WE170V Service Manual

10.18.2 Operating principle of the flowmeter

The main components of the flowmeter are:
1. Turbine (with magnet and
counterweight mounted on
the outside)
2 Reed switch (normally open)
3 Magnet
4 Counterweight
Water entering the solenoid valve rotates the turbine (1) and magnet (3), which passes in front of the Reed
switch (2), thus closing it. As this contact opens and closes, it generates pulses (at a frequency that depends
on the water flow rate).
The turbine completes 230 revolutions for each litre of water. The operating range of the flow sensor is
0.2÷10 bar.
Using the signal it receives, the micro-processor can calculate the number of litres of water passing through
the solenoid valve.
Closed contact
Signal 0
50
Open contact
Signal 1