Akai GX-747 dbx Service Manual page 27

Stereo tape deck
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4-2-7 BRAKE CONTROL SYSTEM OF REEL
6
- - ,
2
I
u
"'
"' "'
0
0.
::,
N
u
MOTOR (Refer to Figs. 6-42 to 6-46)
+12V
,&.
TR ◄ 2
2SC2130IG,HI
12.IV
lG
~s
074
R95
1S2473
IOOK
ov
.,.,
20
a:2
a:
fll
a:
m
a:
OV
I~
"
Q
1i !
a:
RI05
IOK
~
TR39,40
2SC94SLI K,Pl
TR38
2SC_94SL
I
P,Q
l
Ri24
20W 36 ohms
IC4
MC1409BCPN
Rl26
100
RL4-3
FAST
IC4
In the mode (Reel Size 7", 0 Stop SW ON),
RWD SW
is
turned ON from a certain counter
number, for example, 0:05:00.
Fig. 6-43 shows how the take up reel motor and
the supply reel motor work. Since Rl 24 36
ohms is connected in parallel to the take up
reel motor, the torque of the supply reel motor
is increased, and the tape is wound by the
supply reel motor. If the counter indicates
0:00: 50 from this position, "H" signal is issued
from IC2
@
(relay control).
"H" enters the base of TR42 through Rl 15 to
RL5·1
RL3-4
PLY/FF
C901
4+4/2S0
,-----7
I
I
~
4~~1
__?~x.Q:...~
cc
YLW
I
I
I
I
I
I
I
I
I
L _ _ _ _ J
Fig. 6-42
-AC -----
Supply
Fig.
6-43
turn TR42 ON and RL5 ON. Fig. 6-44ih ows the
condition when RL5 is ON. R124 31, ohms so
far attached is disconnected from tl~ -take up
reel motor. Suppose the signal of
:C
'.2
@
(reel motor control) is in "L". TR40
i s
OFF via
R108, and TR38 is turned OFF
lia
R104.
TR38 collector will be "H". The bas1 ~f TR49
will be "H" through R106 to turn 1R-39 ON,
i,
e., the switch of PHl-2 is ON.
Therefore, PHl-1 will be ON whenplll-2 is
OFF or vice versa.
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26

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