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10.
. As soon as this lowering operation is complet-
ed, the cam
will have completed exactly half
a tum. Since the actuator drops into the con-
cave section of the cam, microswitch B (base)
is turned off to stop the Timing motor.
. At the same
time that the Timing motor
is
turned
off, the switch
shorting
the cartridge
output
terminal
is turned
off (thereby
dis-
connecting the muting circuit).
As the record commences
to rotate, the tone-
arm is drawn across to the center of the record
(Fig. 5).
5.2
AUTO-RETURN
1.
10
As the tonearm approaches the lead-out groove
of the record, PU plate screw presses against
the
feed
plate,
thereby
moving
the stopper
towards the center shaft (see Fig. 6).
. Once
the stopper snaps
back
by the pin at-
tached
to the motor,
microswitch
B (lower
side) is turned on by the return lever, resulting
in power
being applied to the Timing motor
(see Fig. 6).
Nos. @ to @ in Fig. 6 indicate the sequence
of events
up
until
the Timing
motor
com-
mences to rotate.
. The
cam
rotating
together
with the Timing
motor also rotates the operation plate via the
crank lever, the cartridge output being shorted
during this rotational
operation by the short
switch.
. Rotation
of the operation plate activates the
arm
lifter, thereby
lifting the tonearm
away
from the record.
. The
return lever on the operation plate then
commences
to return
the PU
plate shaft in
order
to return
the tonearm
to the arm
rest
(see Fig. 7).
. After
the tonearm
has been
returned
to the
arm
rest, the
rotating cam
switches
off the
power
to
the main
motor,
and
to all other
parts of the PL-3000 (microswitch A is turned
off when the upper side of the actuator drops
into the concave section of the cam).
Actuator
Short switch
Microswitch
Fig. 4
PU plate shaft
Fig. 5
Fig. 4, Fig. 5
Drive mechanism during record play
(Cam rotated half a turn)
Stopper
Feed plate
PU plate screw
Crank lever
Microswitch A
Microswitch B
| O
Rotary cam
Disengage lever
Fig. 6
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