Description Of Indoor Unit Control Circuit - Toshiba RAV-162BH-PE Service Manual

8. DESCRIPTION OF INDOOR UNIT CONTROL CIRCUIT

8.1 Serial signal circuit
indoor units)
This is a circuit for transmitting and receiving the signals
between the indoor and outdoor units in serial signal. As
230V is used for transmitting the signal, the microcomputer
section is insulated by means of photo-coupler with the
voltage reduced to 5V.
With AC interrupt, judgement is made as to the presence or
absence of serial signal based on the reference pulse taken
out from the voltage across R and S.
AC interrupt
Serial signal
AC interrupt
Serial input
/ ... are measurement points on the printed circuit board.
provides flashing (orange) on LED in the serial input.
8.2 Float switch circuit
In normal condition in which float switch is not operated,
230V is applied across the pins 1 and 2. At this time, point
is at the GND level. If the float switch is operated,
be at the level of 5V.
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AC interrupt Serial input Serial output
Float switch
Blk
SERIAL/
COMP
C N 0 3
W H I
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