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4.3 MOTOR ASSEMBLY
:
The newly developed quartz PLL Hall element
motor used in the PL-L800
features
a number of
basic
improvements
over
motors
traditionally
= Block Diagram
employed as turntable drive motors.
= Basic Differences
1.
PA2005:
6-phase
drive
circuit;
three
Hall
elements.
PA2008:
4-phase
drive
circuit;
two
Hall
elements.
0.167mS
2.
PA2004:
2-frequency
F/V converter circuit.
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PA2007:
Single-frequency
F/V
converter
ss
circuit (loop gain increase)
3.
The
stop
circuit
previously
fabricated
in
. Vt
cei
ds
PA2005 is now included in PA2007.
Another
new function is the lock indicator illumination
i
circuit built into PA2007.
Also, the pins of the
control
IC PA2007
are provided
with multi-
function
capability
for
increased
control
versatility.
@ Pin
@® Pin
@ Pin
2.2V
PA2007
®
Pin
ImVr.ws
UO
@
\
Pin
= Simple Signal Path
IC
PD1008,
motor
drive
IC
PA2008,
and
IC
G) Pin
TD62503P
functioning
to
produce
the various
7I1V
+
3.6V
operational switch signals.
24V
Z
iC4
TP6250
3P
6.3V
Phase-lock
discriminator
circuit
The
signal picked
up
from
the speed sensor
section is amplified
by the FG amp, then convert-
ed to the speed sensor signal voltage (DC) by the
F/V converter.
Reference phase voltage is obtained by extract-
circuit
ing the reference phase from PD1008 pin 15, then
DOOD
vee 2
sending it through the P/V converter to be used as
ORO ve
reference phase voltage (DC).
The
speed sensor
signal voltage and
reference
phase
voltage
are
each
passed
through
a buffer
to TD62503° (i)
amp
and
resistance
and
combined
(compared).
The resulting voltage is taken from the IC PA2008
pin 6 and input into the absolute value amp, and
is used to control the 4-phase drive circuit motor
rotation voltage, maintaining the motor at a fixed
speed.
vcc 2
10V
Voltage
regulator
circuit
=a
Divider
(2)
4-phase
drive circuit
WA
To VCC 1
= Speed Sensor Section
1.
The
speed
sensor
board
consists
of a single
printed circuit.
45 rpm.
4.
The
output
signal is sent to PA2007
as a
balanced input.
to VCC
2
Hall element
13
12
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