Sansui P-M7 - Circuit Operations (DD Motor, Indicators, Muting, Editing); Timing Charts for Automatic and Manual Operations

C. DD Motor Control Circuit
If the START/STOP switch is depressed when the turntable stops, a
L-voltage level signa! is outputted from the pin No. 19 of the micro-
computer and is inputted to the pin No. 11 of the DD motor control
IC (TC9142P), When a L-voltage level signal is inputted to the pin
No. 11, the turntable rotates.
D. Music Selection Indicator Circuit
In the automatic music selection operation, the selected musics are
stored into the microcomputer and displayed on the indicator.
In playing a music, the indicator light blinks as follows:
When the tone arm lead-in operation stops in a modulated groove,
the indicator light begins to blink the instant a lead-over groove is
detected (the F2 signal changes from a L-voltage level to a H-voltage
level). Further, when the tone arm stops in a lead-over groove, the
indicator light begins to blink the instant the micromotor (II) stops.
Furthermore, in continuously playing musics, the indicator light
begins to blink the instant a lead-over groove is detected (the F2
signal changes from a L-voltage level to a H-voltage level).
E. Computer Operation Indicator Circuit
The output signal from the pin No. 17 of the microcomputer turns
on or off the fQ1, so that the indicator light blinks.
The indicator light blinks during the micromotor (1) or (II) is ro-
tating. However, in case of such a miss-programming that only one
music number not included in a record disc is selected or in case of
no record disc, the indicator blinks much faster then its of normal
operation after the return operation begins.
® MICRO COMPUTER
Timing chart 1 AUTO MUSIC SELECTION 2-3-5 (30cm, 33 rpm)
MICRO COMPUTER MB8841-566M
AUTO MUSIC SELECTION 2-3-5(30cm, 33rpm)
MUSIC SELECTION (2-3-5)—*LEAD IN( 1 )—>PLAY2—>
P-M7
F. Muting Circuit
The muting circuit is a circuit to short-circuit the output signal from
the player, where necessary.
The muting operation is performed by using the output signal from
the pin No. 18 of the microcomputer.
1) tn the automatic disc size selection and the UP/DOWN key de-
pression, the muting is off when the tone arm is down, and is on
when the tone arm is up.
In the automatic music selection operation (See Timing Chart),
the muting is off the moment the tone arm moves down com-
pletely after the lead-in operation (the micromotor (Il) stops
rotating counterclockwise).
Further, when the stylus moves down onto a modulated groove,
the muting is off the moment the F sensor detects a lead-over
groove (the F2 signal changes from a H-voltage level to a L-
voltage level).
2
—
G. Computer Editing Circuit
In the same way as in the muting circuit of the player, the computer
editing operation is performed by connecting the output signal from
the pin No. 18 of the microcomputer to the pause circuit of a
cassette tape recorder through a AND circuit. This circuit controls
the recording on-or-off operation on the cassette tape recorder side
in accordance with the automatic operation on the player side.
in other words, when the muting on the player side is on (the pin
No. 18 of the microcomputer is at a L-voltage level), the pause on
the cassette deck side is on; when the muting on the player side is
off (the pin No. 18 is at a H-voltage level), the pause on the cassette
deck side is off.
Tess Ie
Parmer eee ST ARSENE |
INPUT/OUTPU PIN No. —PLAY3—>CUT (UP/DOWN) ->PLAYS—>LEAD OUT Iga LTO FTA Oo pat A
<= | ES
Ra | 26
BS Rs 27
c Re | 28
U R7 | 29
SENSOR }|——+——_]
D | Re | 30
is E2 | Tc | 8
—
& E3 IRQ 4 30cm Selection
UP/DOWN SW. _| Ris, K2| 35, 40 } tL Ube Hoown
Ris, K2| 37,
MUSIC 2." [Risse 92,40: _ oa eae a
SELECTION} 3 |Ris, K:| 37,39 | |
Sw. 7
5 Ria, Ko] 36, 38
ey a Se BZ y | a)
MOTOR(I) | cow | Ro | 22 ||
MICRO. | cw | R 25 i
MOTOR (II) iz | (|
(Lifter) CCW |} Ra 24 OOWN uP uP DOWN uP
bb START BOWN
5 [DDMOTOR Jerop | Os | 19 ia |_|
2 MUTING Os | 18 ON OFF Fon [FL ow _| OFF ON
SPEED 33/45rpm. | Or | 20 L bet
nee P| io) bee ss §@H Weems TT
—— ee 2
SELECTION Pe | il [n/n
i 3 3
ar) ERE