9-8) Eeprom Circuit; 9-9) Option Circuit; 9-10) Load Drive Circuit - M2 MC2125PALS Service Manual

Circuit Descriptions

9-8) EEPROM Circuit

EEPROM is semiconductor memory not to be
erased. It can be used in the area of unstable
electric power.

9-9) Option Circuit

There are a variety of models that have a
different function. A different model can set up to
use option circuit as shown.

9-10) Load Drive Circuit

1) The control of load in the system is accomplished by the main PCB.
2) Most of relays or SSRs can control the compressor, refrigerator/freezer defrost heater, and several option functions.
3) For the compressor, #18 pin of micro processor signals High (5V). This signal enters #5 pin of IC3 and #14 of output
terminal which have base and collector functions of IC3 turns on and connects the GND. Relay 73 will be grounded
through #14 of IC. Magnetic field will generate so that the second side of RY73 is activated and 115V is supplied to
the compressor. On the other hands, if #18 of micro processor turns Low(0V), #5 of IC3, the current of RY 73 relay,
and magnetic field will shut down in sequence. A contact point in secondary side of Relay 73 is off. Finally compressor
will stop.
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