![Hitachi RAC-18YH4 Скачать руководство пользователя страница 36](http://html.mh-extra.com/html/hitachi/rac-18yh4/rac-18yh4_service-manual_139624036.webp)
– 39 –
2
1
7
3
5
NORMAL : HI
RESET
: LO
RES
Microcomputer
C524
C522
C521
R551
IC521
0V
R552
5V
MODEL RAS-18YH4
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.
Power "OFF"
Power "ON"
Reset enter at 4.2V
Reset release at 4.4V
Voltage
Voltage
Voltage supply to
pin 2 of IC521
Voltage at pin 7
of microcomputer
5.0V
Fig. 1-2
Fig. 1-1
5.0V
DESCRIPTION OF MAIN CIRCUIT OPERATION
1. Reset Circuit
Содержание RAC-18YH4
Страница 21: ... 19 GRAM 18YH4 RAC 18YH4 CAUTION The marked parts are very important ones for safety ...
Страница 23: ... 21 RAS 18YH4 MODEL ...
Страница 24: ... 23 RAC 18YH4 MODEL H8 3 0 3 9 AX 8 T 1 0 ...
Страница 27: ... 26 MAIN P W B MARKING ON P W B COMPONENT SIDE SOLDERING SIDE MODEL RAC 18YH4 ...
Страница 29: ... 29 button MODEL RAS 18YH4 BASIC MODE 31 33 33 33 37 35 ...
Страница 35: ... 38 REFRIGERATING CYCLE DIAGRAM MODEL RAS 18YH4 RAC 18YH4 SUCTION TANK SUCTION TANK ...
Страница 99: ...Printed in Japan TSK AW NO 0004E RAS 18YH4 RAC 18YH4 ...