Akai AP-M7

5-7,
ARM
LIFTER
CIRCUIT
(Refer
to
Figs.
5-5
to
5-7)
p10
out
TRIS
Fig. 5-5 Arm Lifter Drive Circuit
PLUNGER
DRIVE OUTPUT
PLUNGER HIGH
DRIVE OUTPUT
TRIG TRIS
oN. ——> OFF
! i
130m see =
Fig. 5-6 Voltage at the Collector of TR16
1c5 PIN @
1c5 PIN ©
VOLTAGE SUPPLIED TO
PLUNGER (SL9O1)
1) The Plunger high drive output (ICS pin ®) is “H”
when the Tone Arm is raised and also while the Tone
Arm is up, and “L” for 1.6 seconds while the Tone
Arm descends and “H” after that 1.6 seconds as
shown in Fig. 5-7.
The Plunger drive output (ICS pin ©) is “H’” when
the Tone Arm is raised, also while the Tone Arm is
up, and “L” while the Tone Arm descends, also while
the Tone Arm is down.
2) Consequently, in the cases when the START button
is depressed or the DOWN button is depressed in
i
1
I< ARM"UP"->t= ARM"DOWN" >< ARM“DOWN“ >i ARM "UP “
(PLUNGER HIGH DRIVE)(PLUNGER LOW ORIVE)
Fig. 5-7. Timing Chart
comes “L” for 1.6 seconds and ICS pin © becomes
“L”, so TRI7 & 18 are turned “ON” for 1.6 seconds
and also TRIS & 16 are turned “ON”. Thus the Arm
Lifter Plunger (SL901) is driven by +29V (Plunger
High Drive) for 1.6 seconds and is also driven by
+12V after that 1.6 seconds.
3) In the cases when the CUT or UP button is depressed
or Auto Lead-in is activated, ICS pin © becomes
“HW” (ICS pin ® is still “H”) so TRI7 & 18 are
turned “OFF” and TRIS & 16 are turned “OFF”
after 130 msec (so that MUTE works before the Tone
~~~ either AUTO-or-MANUAL-modes;1€5-pin-@-be-— — —~Arm-rises)-by-C37as-shown-in-Fig-5-6,———-_——-—
‘SERVICE MANUAL AP-M7/S: