Sony PS-X65 - Page 5

3.
Tonearm
Swiveling
Circuit
(see
Fig.
3):
Turning
the
power
switch
on
returns
the
tonearm
to
the
arm
rest.
[ > : BACK]
When
S507
(
>
:
BACK)
is
turned
on,
the
voltages
at
terminals
(17)
and
(18)
of
IC102
become
high
“1”.
This
turns
the
voltages
at
terminals
(6)
and
(7)
of
IC110
respectively
to
positive
and
negative.
A
negative
voltage
then
appears
at
terminal
(1)
of
1C110.
M
L
OV
PS-X65
As a result, Q125 turns on to pass current through
L503 (horizontal drive coil) in direction A, returning
home the tonearm.
[<: FORWARD]
When S506 (<): FORWARD) is turned on, the
voltages at terminals (15) and (16) of IC102 become
high ‘1, This turns the voltage at terminal (1) of
IC110 to positive, and, consequently, switches Q124
on. Ds
Now that Q124 is on, current flows through L503
in direction B, moving forward the tonearm.
FORWARD
STOP
4,
Automatic
Disk
Size
Detector
(see
Fig.
4):
As
long
as
the
turntable
is
rotating,
the
light
from
PLSO1
passes
through
the
prism
on
the
turntable
mat
and
switches
phototransistors
Q501
and
Q502.
The
outputs
of
Q501
and
Q502
are
fed
to
termi-
nals
(30)
and
(31)
of
1C102
to
be
used
for
automatic
detection
of
the
disk
size.
Terminal (30) Terminal (31)
ane ae ee See
ae ee ee
No record
PL501 6 ae
B-—
Fig. 3
when no record
placed —-- 2 cee a
0 V —_——————____ when no record
when
a
record
B+
placed
|
| |
1
placed:
OV
OV
when a record placed: OV
when a record placed: 0
when no record placed: 1
Fig. 4
—5—