OPERATION PRINCIPLES BY PARTS OF CIRCUIT
5-7) DAMPER CIRCUIT
1)The temperature of
2)TA7774P (IC07) operates the damper. TA7774P is the driver IC only for step motor. If the regular signal is provided to TA7774P from Micom, send combined signal to
3)Since the damper always touches the cold air, DC 12V/1W heater is installed, always on to prevent the malfunction from moisture and is controlled on conditions. (Operation conditions can be changed). Micon #15 pin connected to IC4 controls the damper heater like category 3.
5-8) DISPLAY Circuit
1) KEY SCAN
When Grid #6 is output, this signal goes through PCB resistance 10 ㏀ and provided to power frequency. When the switch is pressed, R502(6.8 ㏀) and R501 (12 ㏀) decrease the signal and less than 5.1V peak to peak signal is provided to MICOM, the MICOM recognizes the grid #6 is provided, and change the function corresponding to switch key. [Refer the circuit diagram below]
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