Hitachi RAK-25PEB Service Manual page 46

Caution
The indoor fan motor and drive circuit are connected to the primary power supply. They therefore have voltage to ground.
Guard against electric shocks.
Caution
cause a high voltage to r
the C003 before detaching or reattaching the connectors.)
computer. After the amplitude of this
signal has been set to 12Vp-p by a
transistor
5
[Typical communication waveform]
Remote control reception input
(pin of microcomputer)
66
Beep (reception tone)
5V
An infrared signal from the remote control unit is converted to an electrical signal by the remote
control light-receiving unit (IC821) and is received by the microcomputer. Data is transmitted as
digital data 0 and 1 by changing the interval of the basic pulses at about 420 s.
ny circumstances detach or reattach a connector. Any such practice would
r.
Approx. 400 ms.
Enlarged reception waveform
420 s.
Approx.
fan motor and board circuit being destroyed. (Check the discharge of
+
GND
Fig. 5-2
46
R640
66
INPUT