Daewoo DWF-7588TE Service Manual page 19

WATER LEVEL SENSOR UNIT
1) CIRCUIT DIAGRAM
M
I
R18,220Ω
C
24
O
M
2) EXPLANATION OF CIRCUIT
• Push the power switch. And, in order to carry on the action of course selection, input the selection of
frequency according to each water level selection.
• The frequency of water level sensor in each water level becomes square wave and is sended to the
MICOM.
WATER LEVEL NAME FREQUENCY WATER LEVEL
HIGH 22.52KHz 400±15
MIDDLE 23.04KHz 340+10, -15
LOW 23.56KHz 280±15
SMALL 24.05KHz 220±15
E.SMALL 24.33KHz 180±15
RESET 25.02KHz
60 ± 20
0 25.40KHz
If the water level is selected 'HIGH' in washing, water suppply proceeds until inputing the frequency 22.70
KHz of 'HIGH' in the MICOM terminal No. 24. Being finished the water supply, washing process is
proceeded. After the washing process, water level reaches to RESET point, and then after the (D) + 60
seconds, the spin process begins.
• The value of the frequency between the MICOM terminal No. 24 and the GND.
5.4V
0V
f=22~25KHz
3) CAUTION FOR A/S
• The output of the frequency in the WATER LEVEL SENSOR varies in accordance with temperature and
using condition. If it doesn't input the output of the WATER LEVEL SENSOR in the MICOM, the error
message is displayed as 'E9'. In case of proceeding the water supply continuously in 'HIGH' water level,
it is desirable to change the WATER LEVEL SENSOR because of the defect in the WATER LEVEL
SENSOR.
• Check the TR Q4(A1270Y)
• Being checked with tester, the value of the voltage reaches about 4V.
• As the frequency is low, the water level is higher.
R21,10KΩ
Q4
A1270
R22, 3.9KΩ
R20,10KΩ
DWF-7588 DWF-9288 DWF-1088
80L 98L 96L
68L 78L 81L
55L 61L 65L
42L 48L 49L
30.5L 33L 36L
KHz
32
ELECTRIC POWER SUPPLY UNIT
1) CIRCUIT DIAGRAM
D1,1N4003
16
C3 6
C13 C34
3300µF 470µF
104Z
10V 16V
2) EXPLANATION OF CIRCUIT
• The primary voltage of the transformer sets 220V, the secondary voltage of the transformer is full
wave rectified by use of the D7 (1N4003) & D8(1N4003).
1 The gray & red (The waveform in
secondary part of the transformer)
f=60Hz
Vpeak=11.4V
Vrms=8V
2 Measuring the wave form in case of the
removing condenser by the removal ripple
C33
12V
0V
3 It is removed the ripple with attaching the
C33(2200µF).
0V
REGULATOR
D8,1N4003
220V
7806
C32
C33
104Z 2200µF
35V
COMMON
D7,1N4003
4 The waveform of output in the
REGULATOR I.C 7806.
6V
0V
5 The waveform after passing the D2.
5.4V
0V
12V
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