LG Gr P227 Ytqa Service Manual

							1-6. Switch entry circuit
The following circuits are entry circuits for sensing signal form test S/W, electronic single motor damper reed S/W for
examining refrigerator.
1-7. Option designation circuit (model separation function)
The above circuits are used for designating separation by model as option and notifying it to MICOM. Designation of option
by model and the application standards are as follows:
uThese circuits are accurately pre-adjusted in shipment from factory and so you must not additionally add or remove
option.
EXPLATION FOR MICOM CIRCUIT 
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Separation Connection Status  Application Standard
Connection Export model
OP1
OUT Domestic model
 
						

							1-8. Stepping motor operation circuit
EXPLATION FOR MICOM CIRCUIT 
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							For motor driving method, rotation magnetism is formed at coils wound on each phase of motor and stator and so motor
becomes to rotate if applying “High” signal to the IC8 (TA777AF) at the MICOM PIN 33 and outputting “High”, “Low” signal
by step numbers fixed through MICOM PIN 34 and 35,.
Explanation) For driving method of the stepping motor, send signals in the cycle of 3.33 mSEC using terminal of MICOM
PIN 33, 34 and 35 as shown in wave form of the following part. 
These signals are output to the output terminal (No.10, 11, 14, 15) via the input terminal (No. 3, 6, 8) of the
IC10 (TA7774F) as IC for motor driving. Output signals allow motor coils wound on each phase of stator to
form rotation magnetic field and the motor to rotate. Inputting as below figure to the input terminal (INA, INB)
as IC (TA7774AF) for motor driving allows motor coils wound on each phase of stator to form rotation
magnetic field and the stepping motor damper to rotate
EXPLATION FOR MICOM CIRCUIT 
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INA
INB
A
B
A
B
CCW (Reverse rotation) (Positive rotation) CW
 
						

							1-9. Fan motor driving circuit (freezing room, M/C room)
1. This circuit performs function to make standby power ‘0’ by cutting off power supplied to ICs inside of the fan motor in the
fan motor OFF.
2. This is a circuit to perform a temporary change of speed for the fan motor and applies DC voltage up to 7.5V ~ 16V to
motor.
3. This circuit performs function not to drive the fan motor further by cutting off power applied to the fan motor in the lock of
fan motor by sensing the operation RPM of the fan motor.
EXPLATION FOR MICOM CIRCUIT 
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a ,  d  part b  part e  part
Motor OFF 5V 2V or less 2V or less
Motor ON 2 ~ 3V 12 ~ 14V 8 ~ 16V

 
						

							EXPLATION FOR MICOM CIRCUIT 
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b
a
e
d
 
						

							EXPLATION FOR MICOM CIRCUIT 
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b
a
e
d
b
a
e
d
 
						

							1-10. Temperature compensation and over-cool/weak-cool compensation circuit
1. Temperature compensation at freezing room, cold storage room 
EXPLATION FOR MICOM CIRCUIT 
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							EXPLATION FOR MICOM CIRCUIT 
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uTemperature compensation table by adjustment value (difference value against current temperature) 
Ex) If changing compensation resistance at a cold storage room (RCR1) from 10 kΩ(current resistance) to 18 kΩ
(modified resistance), temperature at the cold storage will increase by +1°C. 
Ex) Now (R)J1=           , (R)J2=1.2kΩ, RCRI=5.6kΩwant to compensate -2°C for Freezing room temperature and
+2°C for Cold storage room temperature
(R)J1 = 12kΩ1kΩ
(R)J2 = 12kΩ
RCRI = 5.6kΩ18kΩ
Freezing room Cold storage room
Resistance value
Temperature Resistance value Temperature Remarks
(R)J1       (R)J2compensation (RCR1) compensation
+5 °C 180 kΩ+2.5 °C Warmly 
+4 °C 56 kΩ+2.0 °C compensate
+3 °C 33 kΩ+1.5 °C
+2 °C 18 kΩ+1.0 °C
+1 °C 12 kΩ+0.5 °C
0 °C 10 kΩ0 °CReference temperature
-1 °C 8.2 kΩ-0.5 °C
-2 °C 5.6 kΩ-1.0 °C
-3 °C 3.3 kΩ-1.5 °C
-4 °C2 kΩ-2.0 °C Coolly 
-5 °C 470 Ω-2.5 °C compensate
6.2 kΩ
5.1 kΩ
3 kΩ
2.4 kΩ
1.2 kΩ
1 kΩ
1.8 kΩ
2.7 kΩ
3.9 kΩ
5.1 kΩ
: JUMP WIRE
 
						

							uTemperature compensation table at the cold storage room is as follows:
uThis circuit is a circuit to enter the necessary level of temperature compensation for adjusting different temperature every
model at the cold storage room into MICOM.
EXPLATION FOR MICOM CIRCUIT 
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470 Ω2 kΩ3.3 kΩ5.6 kΩ8.2 kΩ10 kΩ12 kΩ18 kΩ33 kΩ56 kΩ180 kΩ
No 0.5 °C1 °C 1.5 °C2 °C 2.5 °C3 °C 3.5 °C4 °C 4.5 °C5 °C
470Ω
changeUp Up Up Up Up Up Up Up Up Up
0.5 °C No 0.5 °C1 °C 1.5 °C2 °C 2.5 °C3 °C 3.5 °C4 °C 4.5 °C
2 kΩ
Down changeUp Up Up Up Up Up Up Up Up
1 °C 0.5 °C No 0.5 °C1 °C 1.5 °C2 °C 2.5 °C3 °C 3.5 °C4 °C
3.3 kΩ
DownDownchangeUp Up Up Up Up Up Up Up
1.5 °C1 °C 0.5 °C No 0.5 °C1 °C 1.5 °C2 °C 2.5 °C3 °C 3.5 °C
5.6 kΩ
Down Down DownchangeUp Up Up Up Up Up Up
2 °C 1.5 °C1 °C 0.5 °No 0.5 °C1 °C 1.5 °C2 °C 2.5 °C3 °C
Cold storage 8.2 kΩDown Down DownDropchangeUp Up Up Up Up Up
room2.5 °C2 °C 1.5 °C1 °C 0.5 °C No 0.5 °C1 °C 1.5 °C2 °C 2.5 °C
(RCR1) 10 kΩ
Down Down Down Down DownchangeUp Up Up Up Up
3 °C 2.5 °C2 °C 1.5 °C1 °C 0.5 °C No 0.5 °C1 °C 1.5 °C2 °C
12 kΩ
Down Down Down Down Down DownchangeUp Up Up Up
3.5 °C3 °C 2.5 °C2 °C 1.5 °C1 °C 0.5 °C No 0.5 °C1 °C 1.5 °C
18 kΩ
Down Down Down Down Down Down DownchangeUp Up Up
4 °C 3.5 °C3 °C 2.5 °C2 °C 1.5 °C1 °C 0.5 °C No 0.5 °C1 °C
33 kΩ
Down Down Down Down Down Down Down DownchangeUp Up
4.5 °C4 °C 3.5 °C3 °C 2.5 °C2 °C 1.5 °C1 °C 0.5 °C No 0.5 °C
56 kΩ
Down Down Down Down Down Down Down Down DownchangeUp
5 °C 4.5 °C4 °C 3.5 °C3 °C 2.5 °C2 °C 1.5 °C1 °C 0.5 °CNo
180 kΩ
Down Down Down Down Down Down Down Down Down Downchange
Modification
resistance
Current
resistance
 
						

							1-11. Display Circuit
EXPLATION FOR MICOM CIRCUIT 
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