Sony PS-FL1 - Motor Circuit Description; Motor Description and Operation

PS-FL1 /FL1C
1-2. CIRCUIT DESCRIPTION
MOTOR
The
method
for
detecting
change
in
turntable
rota-
tion
speed
for
the
BSL
(Brush
and
Slotless)
DC
servo
motor
on
this
set
is
different
from
the
conventional
method
(detection
by
MG
head
fixed
to
the
frame).
On
this
set
it
is
performed
by
the
FG
board
fixed
to
the
stator.
Motor Internal Diagram
(upper surface)
FG Board
Stator Motor Coil
For this purpose, 256 poles of magnetization (SN
alternately)
are
shallowly
layered
on
the
surface
of
the
drive
magnetizer
(8
poles
alternately
SN)
on
the
magnet used to rotate the rotor.
The frequencies detected at the FG board are:
33'/3 rpm---- 71.1 Hz
45 rpm---- - -96.0 Hz
(cross-section)
shaft
magnet
FG board
coil
bearing
stator
External View of FG Board (with rotor removed)
FG Board
coil pattern
(256)
(external flux noise negation pattern)