LG WF-T851 Service Manual page 11

2-9. NEW UNBALANCE SENSOR (OPTICAL BALL SENSOR) / WF-T851, T902
To detect unbalance, the optical sensor, BALL SENSOR, is used, which is differed from SAFETY SWITCH
incoporated in others models. In normal operation, +5 of voltage is applied between DIODE and TR. In the
abnormal operation like unbalance of clothes during spinning, etc, the ball inside of case is moved from the
hole. In this case any voltage is not applied between DIODE and TR. That is unbalance detection system of
this model.
2-10. AUTO POWER OFF
Power is automatically cut 10 seconds after wash progrom finishes.
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