47
6) When the digital clock does not operate properly
If clock does not keep exact time, you must check resistor R21, R22 and capacitor C5
LVT1
A
D12
1N148M
R22
10K
R21
4.7K
ZD2
5.1V
C5
104
23
EXINT
IC1
POINT
WAVEFORM
A
4.3V
GND
T
T: 20 ms(50Hz)
16.67ms(60Hz)
T:16.67ms(60Hz)