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®@ In the case of side B playing:
There are produced a low level signal at pin (1) of the
microcomputer and a high level signal at its pin 6) , so that
the switches SW3 and SW1
turn on, and the switches SW2
and SW4 turn off, which
is reverse to that in the case of
side A playing. Therefore, the cartridge for the side B is
allowed
to operate
and that for the side A is stopped.
PHONO
MOTOR
CONTROL
CIRCUIT
This circuit consists of Q201 to 204 and 1C203, and provides
a proper control of the phono motor.
1. Speed (33/45 r.p.m.} Selection
When
_the speed is set at 33 r.p.m., the output signal from
pin 20 of the microcomputer becomes high level to turn
on Q201, thus the phono motor revolving at the speed of
33 r.p.m. When the speed is set 45 r.p.m., the output signal
from
pin
of the microcomputer
becomes low level to
turn
off Q201,
thus the phono
motor
revolving at the
speed of 45 r.p.m.
The
speed
is adjustable with VR201
(for 45 r.p.m.) and
VR202 (for 33 r.p.m.).
2. Normal/Reverse Rotation Selection
@ Normal rotation (with side B playing)
When
the side B is played, there are produced high level
signal and low level signal respectively at pins @)) and @2
of the microcomputer,
and these are changed
in level by
Q202 and _0203 to be applied to 1C203. Therefore, pin (1)
and pin (2) of th phono motor are given negative voltage
and positive voltage respectively, so that the phono motor
revolves in normal direction.
@ Reverse rotation (with side A playing):
When
the side A is played, there are produced high level
signal and low level signal respectively at pin
and pin
@) of the microcomputer, and these are changed in level by
Q202 and Q203 to be applied to 1C203. Therefore, pin(1)
and (2) of the phono motor are given positive voltage and
negative
voltage
respectively,
so that the phono
motor
revolves in reverse direction.
INDICATOR
DRIVE
CIRCUIT
@ Indicator section:
This circuit is made
up of 1C206, Q209 and Q210. When
any of the side A/B selector key, both sides play key and
repeat
key is pushed,
the output
signal from the micro-
computer becomes low level to be applied to the indicator
drive circuit, which then lights up the indicator correspond-
ing to one of those keys which has been pushed:
@ APMS indicator section:
The
APMS
indicator circuit consists of 1C301. When
the
APMS
key is pushed, the microcomputer
produces serial-
data signal to be applied to 1C301, which then causes the
APMS
indicator to light up to show how many programs
have been preset by the APMS function.
C0 CD Cry CCC) ae,
=
open
Ly
Socket,
C
=, —_I
a
:
soms
a
Figure 34-5
M203
FHONO
MOTOR
PHONO
MOTOR
M54546P
Vee_Vec'_O2
Lr
cnr 203 '[OOQOOO
10.3V
GND
PHONO MOTOR ROTATION
Figure 34-1
:
Output
[
Rolle
level
1C203
Phono motor
change
operation
Output
Q202] 0203
Input
Output
Pin | Pin
Pin]
Pin|
Pin | Pin
In reverse ro-
tation (with
L
H
Off | On
H
L
H
L
side A played)
In normal ro-
tation (with
H
L
On | Off
L
H
L
H
sida A played) t
| Stop
L
be |
Off | Off
H
H
E
L
Table 31-1 Phono Motor Control Circuit
Table 34-2
Side B Indicator
> PL 302
Side A
Indicator
GND
ry
From Microcomputer
Pin
Figure 34-3
LED308~LED3I4.
GL 3HD7
From Microcomputer
R308
~
R314
560
Pin >
R3I4
RZ3
RZ
RWi
RO
R39
RIS
RIO
i
ae
From
ome
OM
OV
OV
OV
_oOV_oV_
ov
ov
_ov_w
Microcomputer
8 Pin,
J
Pin>+—
APMS
34
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