Technics ST-9038

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PART
II
initial state
(pin
@
"H", pin
Ø
"L",
pin@
ptn
)
@
changes
from
"H"
fo
"L",
causing
pins
,,H
a
(9
to
go
"H"
and
pin
"'1",
@
remains
"H"
and
@
remains
"L',:.
d:
@
changes from
"L"
to
"H",
but
@
and.
remaiir as
in
b and c.
2-1-2
Start
pulse
generation (differential
circuit)
(The
above is an example of
start
pulse
¡n auto tuning.)
When
S3-3 is
ín
auto
or mono,
B is
+B
(þl)
via
R942
if the
AT
buton
is not
pushed.
W¡rh
the
AT
button
pushed,
one side
of
Cg17 is
grounded'and
the
potential
is momentarily
reduced
to
ground
(L).
But it is
soon
charged
by the
time
constant
of
R942
(10Ko)
and C917
(0.68¡lF),
and
irs
potential
returnes
to the
+B
line.
This
can
be
f igured
as fo
llows.
lf
the AT
button
is
released
early
or kept depressed
longer
will not
change
the
wave form.
AT button
pushed
H
L
H
L
H
L
L
H
H
H
ü
a
b
c
6
4
rogo
L
+B
Auto
Mono
----o
Pink
noise
s3-3
L
H
L
0
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5
5
down
A uto-tu
ning
(AT)
button
\
;
By
of
time
constant
C927 x R942
-
13
-
RS
flip-flop
\t
o)
tr
c\l
\l
o)
tr
t'\
o)
O
+B
,'H,
"L"