LG LSC27931SB Service Manual page 33

1.10 Duct door motor driving circuit
P40
P41
1. When ICE PAD is pressed in order to dispense ICE (Crushed or Cubed), Duct door motor will be energized by 1 second, in
order to open the duct door (+ 12V).
2. While ICE PAD is being pressed, voltage is not present between terminals A & B.
3. 5 seconds after release ICE PAD, duct door motor will be energized by 1 second with the inverse voltage than applied at
opening, in order to close duct door.
Duct door driving waveform
+12 V
1 SEC
0 V 0 V
DUCT DOOR
OPEN
ICE DISPENSER S/W SIGNAL
(ICE PAD)
OFF
R59* R60*
4.7K 4.7K
41
Forward
42 Reverse
CC24*
223
CC25*
223
CC26*
223
ON
VARIABLE TIME
CE18
7 8
+
100uF
/25V
5
10
6
R61
IC8
68,1/2W
4
BA6222
CM4
223/100V
2
3
1
9
5 SEC
OFF
- 32 -
CON6
13
M
14
DUCT DOOR
0 V
CLOSE
1 SEC
-12 V
A
B