10-8) Fan Motor(Bldc) Drive Circuit - Samsung RS257BABB Service Manual

Circuit Descriptions
2-1) CoolSelect Zone
close. So cold air is supplied only to CoolSelect Zone
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.
10-8) Fan Motor (BLDC) Drive Circuit
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 RS253BA, R-fan is operated by AC 115V Motor.
1-2) Voltages between high-speed and low-speed
Measure b (F-FAN)
High
Low
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.
Drawer is controlled by a damper to supply or block cold air. For Quick Cool, the damper will be
TM
Voltage of motor
Measure C (R-FAN) Measure d(C-FAN)
11.1V 10V 10V
10V 10V 8.3V
TM Drawer. For Thaw, the evaporator heater of refrigerator is
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)
42
Remark