Sony TC-765 - Power Supply and Motor Control Circuits

| TC-765
2. Action when switched from Fast Forward ( >>)
or
Rewind
(<4)
to
Forward
(>).
(Refer
to
Fig.
2)
3.
Q748
is
negative-biased
by
the
output
from
FG,
so that it is in the OFF condition, B+ voltage is
®
Action
of
IC701
applied
to
terminal
@
and
there
is
no
output
@p»
(Input)
>
©
>
(Output).-->lamp
lights
from
terminal
©
(Path
).
@r
(Input:
ON)
©»?(Output)->tape
transport
4.
The
revolution
of
the
supply
reel
motor
quickly
slows down and stops. When this happens, the
output from FG becomes zero, Q748 returns
to the ON state. Terminal @)is grounded and
terminal © outputs the control signal and
forward motion starts.
1. When switched from fast forward or rewind to
forward, the output of terminal(5), determined
by the input of terminal @, puts Q719 in the
ON state and the forward lamp lights.
2.
Also,
since
the
supply
reel
motor
has
been
(Once
in
forward,
there
will
be
no
influence
revolving
at
high
speed,
it
does
not
stop
from
terminal
@)
until
again
switching
to
fast
immediately
and
there
is
an
output from
FG.
forward or
rewind.)
Linkaged with supply
reel motor.
LM LLL LL LLL LLL LA I NN PN ANIL LLL LPL LANL NLL LDV MLN EEN GA
3.
Power
Supply
Section
(Refer
to
Fig.
3)
(There
is
a
regulator
in
the
audio
amplifie:
section.)
The power supply section consists of the follow-
ing
four
kinds
of
circuits.
3.
Regulated
power
supply
(24V:
adjustment
required)
for
headphone
amplifier,
bias
oscil
1.
Power
supply
(12V)
for
lamps,
IC701,
and
lator,
and
system
control
section.
solenoid hold.
4. Power supply for solenoid initial-energization.
2. Regulated power supply (24V) for record and ‘
ifi D707
playback amplifiers. Lamp, 16701 joy
Solenoid Hold
Record and Playback Amplifiers 24V
Headphone Amplifier 24V
Bias Osc,
System contro!
Solenoid initial-energization