Advertisement
If the mechanism is in the fast-forward (FF),
rewind (REW), or record-playback (REC/PLAY)
mode. the next mode entered is STOP. If it is
presently in the PLAY mode and the ? reverse
mode switch is selected, it also enters the STOP
mode. But if ? , Q are selected, if first goes through
a direction operation, then into a PLAY status.
_|LJ-L
R I G H T R E E L
M O T O R H A L L
E L E M E N T
P A 2 0 t o
P 0 6 0 0 6
F i g . 1 - 1 6 E n d s e n s o r d i a g r a m
1.6 BLANK DETECTOR IC PA3O1O OPERATION
When the function key is placed ON, and the
reel motor starts tuming, pin 16 of PD6006
goes to a low level. When pin 16 goes low, pin 11
of the blank detector IC (PA3010) also goes low,
lifting MS (Music Search) muting and commenc-
ing MS operations.
As MS MUTE is lifted, the signal is first ampli-
fied, then applied to pin 9, and its level is deter-
mined by the comparator in the next stage. Com-
parator output at point A is as shown in the
Fig. 1-18.
This output is used to tum Tr1 ON, and this in
turn allows capacitor C connected to pin !2 to
dump its charge through Tr1. Thus, pin 13 goes to
a low level.
When there is no input signal present, Tr1 turns
OFF, capacitor C starts recharging, and approxi-
mately 7Omsec later, a high level is output from
pin 13.
Consequently, when an input signal is present,
pin 13 is at a low level, and no signal produces a
high output. This output is used by each of the
function
operations (MS/SKIP, INDEX
SCAN,
BLANK SEARCH, MUSIC REPEAT).
P M S M U T E " " ' L ( P I N I I )
( 8 L A N K S E A R C H O P E R A T I O N )
P M S M U T E ' , , ' H ( P I N I I )
9
,,1,l,..1.,,'..,,. .[h/1.,,.
ll,, r,,1. .
l l
prllrl'n --1'
W
mlffi
ilW
lwwmm
mffiilffi
L
2
5V
70ms+
-Fr
4 v f \ '
t1
t
2 . 5 V
3
I
t-t
Fig. 1-18 Blank detector waves
1 . 7 F U N C T I O N K E Y O P E R A T I O N
The various functions (MS/SKIP, INDEX SCAN,
BLANK SEARCH, MUSIC REPEAT) are activated
by placing the respective key to the ON position.
The timing chart for the pulses output from pins
10, 11, and 12 of CPU PD6006 are shown in Fig.
1-19. As a function key is placed in the ON posi-
tion, a pulse train is input to either pin 36 or 37 of
the CPU. The CPU then determines the timing of
the pulse train, and starts operation of the selected
mode accordingly.
_J-----r_
_J---L
-1_I-
-1J-
- - l
f
- l r ! e - l
i -
c +
-LJ-
-Lr
F i s . 1 - 1 9
A = 5 7 ! S
A = A O I S . C r 2 7 o S
Function key diagram
1. MS/SKIP Operation
When the MS/SKIP Key is placed ON, the FF
( >> ) key is activated, and when the beginning of
a music selection is located, pin 13 of PA3010
drops from high to low. The trailing edge of the
pulse effecting the level drop at the PD6006 pin
sets the REWIND mode and rewinds the tape
back to the beginning of the selection, and enters
the PLAY mode.
Fig. 1-17 Blank detector circuit
Advertisement
