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1 . 1 0 R E A L T I M E C O U N T E R
The CT-9R uses a HaIl element sensor to detect
the rotational speed of the reel carrier, and inputs a
pulse signal to PD6008 for use by the tape counter
and real time counter.
Tape Counter Function
o Tape counter set to "0000" at the time power is turned
o N .
1. When the power switch is turned ON, e1206 is
ON during the 100ms interval required for
cunent to pass through +B, R1214, R121b and
charge C1218.
2. Q1206 being ON also turns qL2O7 ON, and its
collector is at a low level.
3. This low signal is applied to pin B of IC904
(PD6008). Pin 13 thru 18 of IC904 are high,
and pin 19 is low.
4. This output is passed to LED 1101 via the
inverting
amplifier
of
ICg0b
(Mb4b1?p),
setting the display to "0000,'.
5. Thus, the tape counter restarts from .,0000" at
the time power is applied to the unit.
Fig. 1-28 Tape counter function
'no 16r)-l
l \ < t Y l
4 .
5 .
o Tape counter increment/decrement
"nnnn"
1. As shown in Fig. L-29, the Hallvoltage genera-
ted by the Hall element (H252: HB) built into
the right reel carrier is applied to pins 16 and
17 of lC2O2 (PA2010) and is output from pin
1 3 .
2. This output is applied to pin 32 of. IC904
(PD6008).
3. At the same time, the voltage generated by Hall
element (H251 : HA) is applied to pins 5 and
6 of IC903 (NJM2903) and is output from
pin 7.
This output is applied to pin 30 of IC904.
Signal input to pins 30 and 32 cause segment
data to be transmitted by pins 13 thru 1g
(active high), and digital data to be transmitted
by pins 26 thru 29. This changes the numerical
display of the tape counter.
6. When the tape is traveling in the FWD direc-
tion, the pulse shown in Fig. 1-29 is applied
with each tum of the reel, causing the counter
to increase.
7. When the tape is traveling in the REV direc-
tion, the pulse shown in Fig. 1-29 is applied
with each tum of the reel, causing the counter
to decrease.
t o o c o L U M N
( U N I T S )
I C 9 o 4
PrN 30 rNPUl|
L_t
LJ
L
rcao4 f--'l
fi
--.1
',1u,i3., J Ll
l_J L
C O U N T E R I N C R E M E N T
lC904
PIN 30
I N P U T
IC904
P I N 3 2
I N P U T
ffi
m
t o 2 c o L u M N
( HUNORES )
ro! coLUMlt
( rHousaNDS )
R O T O R M A G N E T A N D
H R
H A L L E L E M E N T
R E L A T I O N S H I P
7C202
P I N 1 3
O U T P U T
4-
PULL-UP R€SISTOR
"ula=-ol
JI-I]JA
1 8
Fig. 1-29
Tape counter increment/decrement "nnnn"
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