Samsung RS2578BB - 10-8) Fan Motor(BLDC) Drive Circuit

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Circuit Descriptions
10-8) Fan Motor (BLDC) Drive Circuit
2-1) CoolSelect Zone
TM
Drawer is controlled by a damper to supply or block cold air. For Quick Cool, the damper will be
close. So cold air is supplied only to CoolSelect Zone
TM
Drawer. For Thaw, the evaporator heater of refrigerator is
ON and the damper is controlled by the refrigerator temperature.
2-2) The stepping motor controlled by a Driver IC TA7774P(IC7) operates the damper. The stepping motor uses 4
combined signals to open and close the damper.
Note) To prevent the malfunction from a high humidity, a Dc12V, 1 watt heater is mounted and activated continuously.
1) Motor drive circuit
1-1) This refrigerator adopts a BLDC motor froeduce energy consumption, Motors of the freezer, refrigerator and the
machine compartment are composed of the BLDC. For RS2534, R-fan is operated by AC 115V Motor.
1-2) Voltages between high-speed and low-speed
Note) Under the conditions, the fans will be operated in 2 options, such as High and Low mode. Generally, it is
operated in the High mode during a day time and in the Low mode at night.
Voltage of motor
High
Low
Measure b (F-FAN)
11.1V
10V
Measure C (R-FAN)
10V
10V
Measure d (C-FAN)
10V
8.3V
In the normal operation, MICOM No. 40, 41 and 42 applies a constant frequency; and
MICOM defects the signal to check the failure of motor.
(frequency(Hz)×12 = motor rpm)
Remark