Sony ICF-6800W - Page 18

ICF-6800W |
GATE @
SIGNAL
LATCH SIGNAL a ee ee
LATCHES LATCHES
DECIMAL
COUNTER |~-couwrs FREQUENCY | }—counrs FREQUENCY K-—
DISPLAYS NUMBER oF @
LED
DISPLAYS
NUMBER
|e
JUST
WHEN
FREQUENC
al.
oF
O
YS
NUMBER
DISPLAY AHEAD OF (1) COUNT IS FINISHED AND :
LATCHED
| MEMORIZES DATA OF | DATA IN LATCHING TIME ARE
MEMORY @ COUNTED ALSO COME OUT_TOGETHER WITH MEMOQRIZES DATA
THE DATA OF @) AND MEMORIZED OF (3) COUNTED
IN THE LATCH
Fig. 36
Multiplexer (Refer to Fig. 37)
The signal from the latch circuit is then sent ees
to the multiplexer, This IC controls the LED display
unit by a method called ‘‘Dynamic Drive’’, the
generation of pulses to illuminate the digits of the
LED in order from the 1st to the Sth digit.
Each digit of the LED is lit in sequency at a
fast rate, but appears to the human eyes to be lit
continuously due to the ‘“‘persistense of vision”
effect.
This operation is performed through the multi-
plexer.
f
eae
7
ME
I
i
i
(a
IN
PARALLEL
eT
ee
iy
(ie
an oor LL
es
cas
ee
PULSES
ARE
PROVIDED
3AD
DIGIT
DIGIT
LIGHTS”
a SUCCESIVELY
4TH DIGIT
5TH DIGIT a er cee
Fig. 37
=18'=