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1 . 1 1 C A P S T A N M O T O R C I R C U I T
The rotational speed of the capstan motor is
determined by the frequency output of the full
cycle integral type variable reactance frequency
generator (FG) built into the rotor. This unit con-
verts the frequency of.362.5 rpm to 72\Hz.Voltage
at this frequency output is approximately B0mV
rms, and this value is amplified by approximately
40dB by the FG amp section of PA200Z. This
circuit (PA2007) also functions to shape the wave-
form output by the FG.
The next stage consists of a sample-and-hold F-V
converter designed to convert the frequency out-
put occurring through one eomplete cycle into an
equivalent voltage. This voltage is applied to pin
11 of PA2007 as the speed control signal in the
from of a DC voltage.
The voltage output from pin 11 (PA200?) is
passed, along with the reference voltage from pin
!2 to PA2O72 and input into pin 7 and pin 6 re-
spectively. There it is used to control the current
fed to the motor and reduce fluctuations in the
rotating speed.
The motor is a 4-phase type with Hall elements
electrically phased 90" apart. The Hall elements
serve to detect the positioning of the rotor mag-
nets, and activate the various coils via the composite
positioning circuit (PA2012), providing maximum
efficiency and rotational torque.
CT-9R Reference Frequency Generator Circuit
The CT-9R uses a crystal oscillator as a reference
frequency
generator
increasing the
rotational
accuracy of the capstan motor.
The reference frequency (7.4283MH2) produced
by the crystal oscillator is divided LlStZO by the
divider IC in PD1003 and output as 14b0.8898H2
from pin 15. This signal is input into pin 8 of the
confuol IC PA2007. There, it is once again divided
by Ll2 to produce tlrre 725.4L992H2 phase control
reference frequency.
1 . 1 2 R E E L M O T O R C I R C U I T
The reel motor uses the same drive method as
the capstan motor;4-phase, electrically phased 90"
apart. Hall elements are used to detect the posi-
tioning
of the rotor magnets and activate the
various coils via the PA2010 position detection
signal composite circuit
to
provide rotational
torque and ma:rimum efficiency.
The reel motor is controlled by the PMg001
contuol signal applied to pins 15 and L4 on
PA2009. The various signal combinations (shown
in Fig. 1-36) are used to activate the different
operational modes and control the direction and
speed of the motor.
The signal output from the right reel motor
(MR) Hall element is waveform-shaped into a
square-wave pulse and taken from pin 1g of
PA2010 for use as the tape end sensor and tape
counter signal. (CT-9R only)
M O D E
INPUT (PA2OOg}
R E E L M O T O R O P E R A T I O N A L M O D E S
M L ; P I N 1 5
M R ; P I N 1 4
STOP
L
L
Both reel motors stopped
F . P L A Y
L
M
Right reel motor constant current drive
R.PLAY
M
L
Left reel motor constant current drive
F F
L
H
Right reel motor fixed speed drive
R E W
H
L
Left reel motor Fixed speed drive
R E W . F F
M
H
Right reel motor max
F F . R E W
H
M
Left reel motor max
Fig. 1-36
Reel motor operational modes
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