– 74 –
9. Reset Circuit
●
Reset circuit performs initial setting of the microcomputer program when power is turned on.
●
Microcomputer resets program with reset voltage set to Lo, to enable operation at Hi level.
●
Fig. 9-1 shows the reset circuit, and Fig. 9-2 shows waveform at each point when power is turned on/
off.
●
After power is turned on, 12V line and 5V line voltages rise: When 12V line voltage reaches 7.2V (Zener
voltage of ZD201), ZD201 turns ON and Q211 and Q205 turn on, and reset voltage becomes Hi. Reset
voltage is not set to Hi until VDD of microcomputer rises to 5V, enabling operation, due to ZD201.
●
After power turns off, when 12V line voltage drops, ZD201 also turns OFF.
12V line
12V line
5V line
5V line
Reset voltage
Reset voltage
12
6
0
V
oltage when power is turned ON
12
6
0
V
oltage when power is turned OFF
Time
Time
Fig. 9-1
0V
0V
0V
C224
5V
Q212
C223
R368
R369
R367
R365
C351
R366
Q205
R345
48
12V
ZD201
Reset
(AX-6V01)
Outdoor
Microcomputer
Fig. 9-2
Содержание RAC-50DH7
Страница 30: ... 29 CIRCUIT DIAGRAM Wired Remote Control ...
Страница 31: ... 31 CIRCUIT DIAGRAM MODEL RAD 50DH7A RAD 60DH7A RAD 70DH7A ...
Страница 32: ... 33 CIRCUIT DIAGRAM MODEL RAC 50DH7 RAC 60DH7 RAC 70DH7 ...
Страница 35: ... 39 51 53 53 55 57 49 29 66 Heating ...
Страница 76: ... 86 SELF DIAGNOSIS LIGHTING MODE MODEL RAC 50DH7 RAC 60DH7 RAC 70DH7 ...
Страница 79: ... 89 2 Outdoor unit does not operate but receives remote infrared signal ...
Страница 82: ... 92 CHECKING THE REMOTE CONTROLLER ...
Страница 87: ... 97 16 ...
Страница 101: ...HITACHI PM NO 0411E Printed in Malaysia RAD 50DH7A RAC 50DH7 RAD 60DH7A RAC 60DH7 RAD 70DH7A RAC 70DH7 ...