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RP-107H/117H
©
AUDIO
SIGNAL
DETECTOR
CIRCUIT
When
the unit is in APSS
or APMS
operation, this circuit
detects the beginning or the end of the program of a record
being played, thereby to ensure a proper control of the mut-
ing. When the side A, for example, is now being played and the
beginning or the end of the program
is reached, the output
signal from the cartridge motor is applied to pin
of 1C101
(operational amplifier) where it is amplified, and is sent to the
halfwave
voltage douler
rectifier composed
of D105,
D106,
C112 and C113, then arriving at pin (2) of 1C101. Finally, a
high level signal goes out of [C101, and is applied to pin (3) of
the microcomputer
so that the microcomputer
can tell that
the unit has reached
the beginning or the end of a certain
program of the record being played.
PROGRAM
SPACE
DETECTOR
CIRCUIT
This circuit is made up of a side A sensor (PT101, LED106),
side B sensor (PT102, LED102) and 1C205.
Now
let's consider the case where the unit is in APSS opera-
tion
for
side
A.
Then
the
infrared
ray
emitting
diode
(LED106)
and
phototransistor
(PT101)
work
together
to
differentiate a program space of the record being played from
its programs
recorded
part by sensing difference
in terms of
infrared reflectivity between these two parts.
That is, when the APSS sensor detects a program space of
the record, there appears a signal at the emitter of PT101
of
which the waveform is as shown in
of Fig. 36-2. This signal
is applied to 1C205 where it is amplified, and arrives at pin
of 1C204.
To the same pin of !C204 is also applied a com-
Parison signal
which has been attenuated by the attenuator
made
up of R268,
R270
andR271.
Besides, to pin
is
applied a reference signal
of which the waveform
is made
gentle by R269, R273 and C224.
Finally there
is caused a high level pulse (0) at pin 3) of
1C204 which results from comparison between the comparison
signal and reference signal, and is fed to pin
of the micro-
computer,
which causes the microcomputer
to find out that
the APSS sensor has been sensing the record's program space.
SYNCRO RECORDING CONTROL CIRCUIT (RP-107H only)
When
the
player
RP-107H
is connected
to the amplifier
SA-107H
and cassette deck RT-107H, it becomes possible to
perform
synchro
recording
between
the player and cassette
deck.
To start the synchro recording operation:
First of all set the synchro switch of the player RP-107H to
"on"
position
while
keeping
the cassette deck
RT-107H
in
record/pause mode. And when the play/cut key of the player
is pushed, the tonearm moves down to the record surface and
the muting is released to allow the player to start operating.
With the player turned on, there appears a low level pulse (200
msec) at pin
of the microcomputer to turn off_Q208 so
that a high level pulse (200m sec) goes out of pin (6 )of DIN
socket. With this pulse given, the cassette deck leaves record/-
pause mode and instead goes into record mode, and recording
will begin in the deck.
to Microcomputer
|
@ Pin
APSS Muting
Detector
Signal
Input
From &GnbD
+5V
Cartridge
7
re
36-1
eck
Figure
36
Output Signal
Vv
Input Signal
ov
to Pin
of 1C101
—*
Time
Vv
Input Signal
to Pin 40
oY
of 1C101
—Time
Vv
Input Signal
|
/
ov
//A+High Level
to Pin
of 1C101
—~Time
Figure 36-2
APSS SENSOR SENSITIVITY
SWITCH
a
From Side A APSS Sensor PT101
Fig. 36-3 Program Space Detector Circuit
@) Output signal from the emitter of the Photo-transistor (PT101)
a
i oe
vw AW
©) Reference Signal
Output Signal from Pin 'E) of 1C204
Comparison Signal
eae kan
ea
(D) ov
Figure 36-3
Input Signal to 1C204
=36=
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