8-6. KEY SCAN and DISPLAY circuit part
1. Running of KEY SCAN and DISPLAY
As shown in the following waveform of each part, ÒHighÓ output is sent in turn from MICOM PIN
#3 #4 #5 #6 #7 for 2 msec at 10msec interval using five Terminal of MICOM NO #3, 4, 5, 6, and 7.
This signal appears at OUTPUT Terminal through INPUT Terminal of IC05 (UDN2981 or UPA2981C).
At this time, PEAK TO PEAK voltage of square-wave is about 11 V (DC RMS 1.5 V) and output waveform
is as follows.
2. KEY SCAN
When GRID #1 waveform is outputted, this signal is supplied to the button for temperature-setting of freezing
room through resistance 10 . At this time, when you push button for freezing room, the signal becomes
decreased by R506 (6.8 ) and about 4.5 V of PEAK TO PEAK voltage is approved to MICOM. After supply
of about 4.5 V of PEAK TO PEAK voltage to MICOM, MICOM can judge that GRID #1 waveform is inputted
and then, change the temperature-setting for freezing room. Like this way, each GRID waveform is perceived.
POWER-
FREEZING
POWER-FREEZING
POWER-
REFRIGERATING
POWER-REFRIGERATING
F, R ROOM
DEODORIZATION
DOOR-SECURING
or CUBE
COLDER-HUMIDITY
or CRUSH
Door-Securing ONor
CRUSHED/CUBE
POWER REF
POWER FRE
REFRIGERATOR ROOM SETTING
'
FREEZER ROOM SETTING
Door-Securing OFF or
LIGHT ON/OFF
RED-RED
BLU-BLUE
ORG-ORANGE
BRN-BROWN
PNK-PINK
GRY-GRAY
WHT-WHITE
YEL-YELLOW
BLK-BLACK
PRP-PURPLE
W/BLK-
WHITE/BLACK
S/BLU-
SKY BLUE
REFERRENCE
27