Block Diagram Of Pd5009; D1-D5 Time Division Pulse Signals - Pioneer SX-3800 Service Manual

O I G I T O R I V E R
S E G M € N T D R I V E R
M U ! T I P L E X E R
P R E S E T A E L € 5 - D I G I T
O E C I M A L C O U N T E R
2 2 - 8 l I r
1 6
R O M
G N D
F i g . 4 - 5 B l o c k d i a g r a m o f P D 5 0 0 9
I
I
I
I
I
I
I
t
I
r|
il
i
t
t
t
val. Pin no.? of PD5009 is the brightness selector
terminal. The time division pulse width is set to
8009s for H level input signals, and to 200ps for
L level signals, thereby varying the degree of FL
tube brightness (by varying the segment lighting
period). Note that since the pov.er indicator FL
tube is driven by static drive, the degree of bright-
ness may be varied by changing the grid voltage.
The 5.12MHz crystal oscillator generates the
basic signai used in the preparation of the time
division pulse signal and the counter gate circuit
control signal.
Terminals S1 - S4 (pin nos.3 - 6) are used in
designating reception mode. The 2 reception
modes employed in the SX-3800 (see Table 1) are
designated by varying the combination of input
levels (H and L). The 3 different IFs during FM
mode are required in coping with IF offset in the
IF ceramic filter stage, 53 and 54 being preset
during FM mode according to the ceramic filter
characteristics.
Although the SX-3800 FM stage quartz-lock
system is capable of locking any frequency within
the FM band, the L0kHz digit (digit in the second
decimal place) in the FM frequency display will
appear only as 5 or 0.
The frequency display FL tube also incorporates
the TUNING and SIGNAL indicators. And al-
though the segments (anode) for these indicators
are static driven by the corresponding drive cir-
cuits, the edd is driven according to the D3 time
division pulse timing, thereby placing the segments
1 0
I n l l t t r - o,w
o o M
*l-w
,,iw
- ' l ' * i * i i l l
t{--
tm3
+
8 C = L ( D l M )
F i g . 4 - 6 D 1 - D 5 t i m e d i v i s i o n p u l s e s i g n a l s
under dynamic drive. In addition, the AM and FIW
indicators in the frequency display section are lit
according to the Db timing, while the kHz and
MHz indicators are lit accordine to the D1 timine.
M O D E
s1
S2
s3
I
H
L
H
l F { M H z )
F M
H L L
1 07 3
H L H
H
1 0 . 7 0
H L
't 0.67
A M L
H H L
4 5 0 k H z
T a b l e 1