Ic Block Diagram - Onkyo A-8780 Service Manual

A-8780
1) When it is not backed up
When ENCD5"L", the indicators of the INPUT SELECTOR corresponding to codes ENCD4-ENCD1 wiil light. Also, S1
and §2 will be output. When the ENCDS input is"H", or when the 4-bit code is not effective or is not present, the rotary
switsh will rotate in the UP direction and stop at the nearest effective position, the INPUT SELECTOR will be indicated
and the port will output a signal. If an effective position cannot be found within 10 sec. after this operation has started,
the rotation of the rotary switch will be stopped and all the indicators of the INPUT SELECTOR will flash with a fre-
quency of 1 Hz.
2) When it is backed up
The positions of the INPUT SELECTOR before power went down will be indicated and the port will output a signal.
When ENCDS
is"H", or when the 4-bit code is different from the last one, the rotary switch will be rotated to the last
position. At this time, if the last position cannot be detected within 10 sec., the rotation of the rotary switch will stop and
the indicator of the last INPUT SELECTOR will flash with a frequency of 1 Hz.
IC BLOCK DIAGRAM
TA7317P (Protective circuit)
8 9
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t
' CIRCUIT CIRCUIT
SHUMITT RELAY
: VOLTAGE DISCHARGE SUB i
3—4 DETECTION
CIRCUIT
STRAIGHT
IRCUIT
GND
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7 ri S