Advertisement
RP-107H/117H
©
TRACKING
ERROR
DETECTOR/CARTRIDGE
FORWARD
CIRCUIT
The description here is written for side A playing alone. This
circuit is Composed of photo interrupters P!101
(for side A),
P1102
(for side B), 1C103 and 1C104, and controls the car-
tridge forward operation when a record is playing. As playing
the side A of a record proceeds, the tonearm
becomes more
inclined the angle of which is detected by P1101 (now there is
a light emission
to P1101), and the resultant signal (at high
level)
is applied to pin (2) of 1C104
to drive the cartridge
motor to allow a forward motion
of the tonearm.
And as a
result of forward rotation of the cartridge motor, when the
tonearm
advances to reach the place where
its inclination is
zero, a light emission to P1101
is stopped so that the output
signal from P1101
becomes
low level to turn off 1C104 and
causes the cartridge motor to stop.
This is repeated as far as the record playing continues, and the
same
operation
occurs
for side
B playing too.
If there
is
something accidental to make slantwise the cartridge to cause
its erroneous
angle, there is caused a high level signal at pin
(for side A) and/or pin
(for side B) of the microcom-
puter so that the tracking error output is grounded to stop the
cartridge forward motion.
TONEARM
POSITION
DETECTOR
CIRCUIT
This circuit is made
up of photointerrupter
P!103 and gear
drum. Detected by these, the output pulse is applied to 1C204
(comparator)
where
it is shaped
in waveform,
and then
is
supplied to pin
of the microcomputer.
In the microcomputer, there is a pulse checking function with
which
it is detected how far from the rest position the tone-
arm is now being situated.
The
microcomputer
has the control
addresses
assigned
as
follows:
1. Rest position: 0
2. Lead-in addresses
30cm LP record:
1
25cm record:
58
17cm EP record:
147
3. Lead-out addresses
30cm/25cm record:
219
17cm EP record:
225
4. Lead-in area address
30cm
LP record:
0
25cm record:
48 to 68
17cm EP record:
137 to 157
@
These
addresses are used when
the record size is to be
detected.
SIDE
A/SIDE
B CARTRIDGE
SIGNAL
SELECTOR
CIR-
CUIT
This circuit consists of 1C102 which selects the cartridge for
the side
A or side B of a record to be ready to move
for
playing.
@ In the case of side A playing:
A low level signal is caused at pin
of the microcomput-
er while a high level signal is caused at its pin (1)to turn on
the switches SW2 and SW4 of IC102, thereby to allow the
cartridge for the side A to get in action. At the time, the
switches SW3 and SW1 of 1C102 are turned off not to allow
the cartridge for the side B to operate.
From
Microcomputer
@ Pin
(©) Pin
From
Microcomputer
(G) Pin
a? Pin
From Side
AorB
Photointer- >
+
rupters
@ ~ @>: cnsin
GND
CARTRIDGE MOTOR ROTATION
+10.3V
GND
CARTRIDGE
MOTOR CONTROL
MIO3
npiiz
CARTRIDGE
MOTOR
Figure 32-1
MICROCOMPUTER
@Pin @Pin
aa
GND
+5V
From Photo-interrupter
P1103
<
From Photo-interrupter
P1103
Figure 32-2
From Cartridge
4 .
+
%
Side A
$5
Side B
L-ch
L-ch
From Cartridge
Side A
R-ch Signal
GND
-4 From Cartridge
Side B
Output
R-ch Signal
R-ch<
L-ch«
a
Microcomputer
Microcomputer
C1) Pin
61) Pin
Figure 32-3
99:
Advertisement
