The Principle Of Load Sensing - Daewoo DW-3000 Series Training Manual

5. The Principle of Load Sensing

1. Concept
Experienced customers know how much is the approximate weight of laundries what they want to
wash, and how much of water will be proper for the laundries. So the customers can select the proper
water level and amount of detergent so as not to damage the laundries and not to waste water and
not to contaminate environment.
But, on the other hand, unskilled customers do not know about that. So all of our washers provide
FUZZY course.This FUZZY course has the function to select water level automatically
according to the amount of laundry after checking the amount of laundry.
2. Principle
The basic principle of automatic selection of water level is as follows
1. The basic idea is the INERTIA force and INERTIA energy of rotating parts of washer,
especially Motor and Condensor.
2. Although turning off the power of Motor, the motor will turn more several turns by the INERTIA energy
of Pulsator, Rotor of Motor, Pulley and Shaft of Gear Mechanism.
3. But the number of more turns varied depend on amount of the washing in the Tub. When the washing
in the Tub is small, the Motor will turn more compared to the case of large load. This is because
those laundries in the Tub are disturbing rotation of Pulsator.
4. While the Motor turning more, the Motor will act like a generator. The reason is that after TRIAC,
one of component assembled on the PCB, is turned off the Condensor discharges the charged
electrons generated by rotating of Motor.
So, hereby, the Micom can check the sinewave of voltage generated by the Motor.
5. The Micom, assembled on the PCB, checks the period of sinewave voltage generated by the
Motor just after turning off the TRIAC. When the amount of the washing in the Tub is small,
the Motor will turn more rapidely and long compared to the case of large load.
small washing load
large washing load
TRIAC 'ON'
TRIAC 'OFF'
T r i a c O N T r i a c O F F
'
TRIAC 'ON TRIAC 'OFF'
T r i a c O N T r i a c O F F
start to check period of sinewave
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