18
OPERATION PRINCIPLES BY PARTS OF CIRCUIT
5-5) DOOR SWITCH DETECTON CIRCUIT
1) If R-Door is opened, the contact point of the door switch (4-3) becomes open, and the current of PCB line
comes through R404 and R405 and provides 5 volt which is recognized as door is opened, and turn off the fan
at different load. When the door is closed, the voltage goes out from R404 to Switch, the MICOM is applied
with OV and the door is recognized as closed.
2) If F-Door is opened, the contact point of the door switch (4-3) becomes open, and the current of PCB line
comes through R402 and R403 and provides 5 volt which is recognized as door is opened, and turn off the fan
at different load. When the door is closed, the voltage goes out from R402 to Switch, the MICOM is applied
with OV and the door is recognized as closed.
3) Q401 is the circuit to turn off the auger motor operation when the door is opened. If the door is closed, Vcc
voltage of R402 works as ground via door switch, OV is applied to the base of Q401, and Q401 becomes
operable, Vcc voltage on "A" part Q702 base works as emitter on Q401 collector and creates OV. (Check the
operable condition for other parts at load terminals)
4) Condition for door open is the opposite of condition 3 above.
Category
Door
DOOR S/W Contact Point
MICOM PORT NO
MICOM INPUT
F
R
#50
#49
CLOSE
OPEN
CLOSE
OPEN
CLOSE
OPEN
CLOSE
OPEN
"LOW"
"HIGH"
"LOW"
"HIGH"
