Akai GX-747 dbx

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 is 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.
----------------- SERVICE MANUAL GX-747dbx -------------------
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