– 63 –
●
The reset circuit initializes the microcomputer program when power is ON or OFF.
●
Low voltage at pin
7
resets the microcomputer and Hi activates the microcomputer.
●
When power “ON” 5V voltage rises and reaches 4.4V, pin 1 of IC521 is set to “Hi”. At this time the
microcomputer starts operation.
●
When power “OFF” voltage drops and reaches 4.2V, pin 1 of IC521 is set to “Low”. This will RESET the
microcomputer.
DESCRIPTION OF MAIN CIRCUIT OPERATION
MODEL RAK-25NH5, RAK-35NH5
1. Reset Circuit
Fig. 1-1
Fig. 1-2
2
1
5
3
7
NORMAL : HI
RESET
: LO
RES
Microcomputer
C524
R551
C522
C521
R522
5V
0V
IC521
Voltage
5.0V
Reset enter at 4.2V
Reset release at 4.4V
voltage
5.0V
Voltage at pin
7
of microcomputer
Voltage supply to
pin
2
of IC521
Содержание RAC-25NH5
Страница 31: ... 29 MODEL RAK 25NH5 RAK 35NH5 ...
Страница 37: ...CIRCUIT DIAGRAM MODEL RAK 25NH5 RAK 35NH5 37 ...
Страница 38: ...CIRCUIT DIAGRAM MODEL RAC 25NH5 RAC 35NH5 39 ...
Страница 39: ... 41 PRINTED WIRING BOARD LOCATION DIAGRAM MODEL RAK 25NH5 RAK 35NH5 MAIN P W B Marking on P W B ...
Страница 40: ... 42 MODEL RAK 25NH5 RAK 35NH5 RECEIVING P W B Marking on P W B ...
Страница 41: ... 43 MODEL RAC 25NH5 RAC 35NH5 MAIN P W B Marking on P W B COMPONENT SIDE ...
Страница 53: ... 64 ...
Страница 54: ... 65 ...
Страница 55: ... 66 ...
Страница 56: ... 67 ...
Страница 90: ... 101 SELF DIAGNOSIS LIGHTING MODE MODEL RAC 25NH5 RAC 35NH5 ...
Страница 92: ... 103 2 Outdoor unit does not operate but receives remote infrared signal ...
Страница 94: ... 105 6 Check the main P W B power circuit ...
Страница 95: ... 106 CHECKING THE REMOTE CONTROLLER ...
Страница 100: ... 111 ...
Страница 106: ... 117 PARTS LIST AND DIAGRAM INDOOR UNIT MODEL RAK 25NH5 RAK 35NH5 ...
Страница 112: ...HITACHI PM NO 0324E Printed in Malaysia RAK 25NH5 RAC 25NH5 RAK 35NH5 RAC 35NH5 ...