Daewoo DWF-7588TE, Руководство по обслуживанию

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• Part of the button scan
The system of the BUTTON SCAN is in wide use for the method of the DUTY output part in L.E.D DRIVE,
yet here, it is in use for the method of the segmental output.
• Though the period of the DUTY part is 1/9, the last 9th part does not generate the waveform and checks
the button input with getting out the segmental output at the same time.
• The RA1(473J, 47K
Ω
) is a ‘PULL DOWN’ resistance for preventing floating action.
• The D15 prevents the L.E.D from turning on unnecessarily with forming the closed loop like a threaden
line at the time of button push.
IC6
ULN
2004A
6
5
4
3
SW2 SW6
SW7 SW3
R66,220
R67,220
RA1
4X473J
58
57
59
60
M
I
C
O
M
Duty Part
Segment Part
Waveform
No Generation
Segmental Waveform
for Button Input
BUZZER UNIT
1)CIRCUIT DIAGRAM
2) EXPLANATION 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 the R8 is restrict resistor of the Q1 base current, and the R5 is
resistance of excess current under phenomenon of short circuit, when the electric current changes
abruptly according to the condenser component of piezoeletric element, and the R8 remove the
phenomenon of abnormal oscillation by preventing the collector floating state of the Q1.
• The waveform in the part of the BUZZER DRIVE TR Q1 collector.
BUTTON INPUT UNIT
1) CIRCUIT DIAGRAM
M
I
C
O
M
R7, 10K
R6,1K
Q1
C3202Y
R5, 220
BUZZER
WES27-20P
R8, 620
12V
0V
12V
f=2KHz
t
0V
6V
0V
5.4V
0V