DAEWOO ELECTRONICS DWF-5590D Series, Service Manual, Page: 37 / 63

BUZZER UNIT
1) CIRCUIT DIAGRAM
2) EXPLANTION OF CIRCUIT
• After the button action and total process ends, BUZZER is active.
• It is active directly with offering an output the frequency waveform of 2 KHz from the MICOM terminal No. 7
• The R7 is ‘PULL UP’ resistance, and R8 is restrict resistor of Q1 base current, and R5 is resistance of excess current
under phenomenon of short circuit, when the electric current changes abruptly according to the condenser component
of piezoelectric element, and R8 remove the phenomenon of abnormal oscillation by preventing the collector floating
state of Q1.
• The waveform in the part of the BUZZER DRIVE TR Q1 collector.
BUZZER INPUT UNIT
1) CIRCUIT DIAGRAM
37
M
I
C
O
M
R6,1k
BUZZER
WES27-20P
7
R7, 10k
Q1
C3202Y
R5,220
R8,620 12V
0V
12V
f = 2 KHz
t
7
8
5
4
3
2
1
8
10
11
12
13
14
15
16
9
D11
D12
D25
D24
LOAD
SELECT
D19
D18
D17
D16
OPTION : PUMP
SW3
SW4
D19
D18
SW8
SW7
SW6
SW5
SW12
SW9
D22
1N4148
R66,220
R67,220
R68,220
R69,220
ULN-2004
I.C6
RA1(4X473)
50
51
52
53
54
57
58
59
60
S23
S24
S25
S26
S27
P100
P01
P02
P03
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