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Automatic Function Switching
If audio components featuring "'one-touch auto-
play"?
functions
are
connected
to the
relevant
PHONO
(PL), TUNER
(TX), CD, or TAPE1(CT)
"AUTO
FUNCTION"
terminal on the rear panel
of the A—X700,
the function
is switched
auto-
matically to the operated component.
When the PLAY or STATION
CALL switch of
the component connected to the PHONO, TUNER,
CD, or TAPE1 terminal is switched on, the generat-
ed L level signal is passed to the microcomputer
which
in turn passes
corresponding
data to the
function
switch
(TC9162N)
to effect the actual
switching operation.
Stop Signal
When a function is switched by automatic func-
tion switching or amplifier function switching, an
H level signal is generated at pin 30 of the micro-
computer.
Q301
is thus turned on, and auto stop
output signals are passed to PL, CD, and CT.
Double Deck and Single Deck Switching
S301 is switched according to whether the tape
deck connected
to TAPE1
is a double
or single
deck. When a double deck is used, S301 is switched
on
resulting in pin 25 of the microcomputer
re-
maining
at H level. Q404 is thus turned on, and
Q406 then Q102 are turned off. When Q101 and
Q102 are both turned off, REC1 is switched on.
When S301 is off, pin 25 of the microcomputer
is switched to H or L level depending on whether
or not function has been switched to TAPE1.
If
the function has been switched to TAPE1, pin 25
is switched to L level, resulting in Q101 and Q102
being
turned
on
and REC1
being switched
off.
When
the function is switched to other positions,
the reverse occurs.
Remote Control Terminal
The photosensitive section of the remote control
mechanism is located in the tuner. Upon reception
of a remote control signal in the tuner,
a VR UP,
DOWN,
muting,
VIDEO/AUX,
or tuntable start/
stop signal is decoded by the microcomputer. Re-
mote control signals for CD or TAPE]
are passed
direct from the tuner.
Microcomputer Reset Circuit
+17V(B2)
Q4ot
c401
+5.6V(B1)
[
S76
V(B
R405
Fig. 7-8
ie
= Se
B2 voltage
§.5-—-——-—- 7
Q401 collector
7.4
B1 voltage
eee
Q403 base
; =r. —
0403 collector
Fig. 7-8-1
The
microcomputer reset circuit is outlined in
Fig. 7.7.
When
the power
is switched
on, and the Q401
base voltage
(B,) is increased
to 5.6V
with the
emitter voltage
(B,) in excess
of 7.4V, Q401 is
turned on and the collector voltage is gradually in-
creased to 15.5V. The Q401 output is differentiat-
ed by C401/R405
and then inverted by Q403 to
obtain the reset signal.
D425 has been inserted in the circuit to prevent
Q408 cut-off at the same time the power is switch-
ed off in order to prevent the memory from being
switched
off by reset circuit misoperation if the
power switch is switched on and off in quick suc-
cession. The reset signal resets the microcomputer
once clock oscillation (3.84 MHz) has been com-
menced when the STANDBY
pin (No.37) voltage
is increased after the power is switched on.
15
PD6027 Functions
X
Ene
eS 3.84 MHz resonator is connected
} 2]
x | between these pins.
3 | RESET]
Positive power supply (VOD) connection
Remote control signal input
Serial data output to PD0012, TC9177P,
and TC9162N.
SC/Arg
NC
l=[=[=[ele]e[e]
Output of key matrix
drive signals
TAPE 1
| n
Indicator outputs
m) ow] mle
coy"
<
elelele]
[=] =] =| =|
Strobe outputs
25°| R i
TAPE 1
110W meter range
Back-up mode starter input
Auto function input
b be]
Oo
NTH
w Oo
*
Indicator
outputs
EEEEEGG
37
Key inputs
<
"
u ne
:
Nefelefe}e]
= ] e ]
Vv
ies)
*Pin No. 25.
The R12 pin is at H level. Pin 25 is switched to
L level when
TAPE1
function is selected, but is
switched to H level in other function positions, and
R12 remains at H level.
*Pin No. 30
Switched
to H level for 100msec
immediately
following function switching.
16
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