DAEWOO ELECTRONICS DWF-5590DP Series, Service Manual, Page: 38 / 63

• 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.
• RA1 (473J, 47K
Ω
) is a ‘PULL DOWN’ resistance for preventing floating action.
• 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.
38
Duty part
Waveform
No Generation
Segmental Waveform for
Button Input
Segment part
51 BUTTON SCAN
6
IC06
62 SEGMENTAL PART
MICOM
57
PART OF THE
BUTTON INPUT
58
RA1,473J
D15 D11
D13 D12
SW3 SW3
SW4
R66.22O
R67.22O
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