Revox B261

sruotrR nd/ox
8261 SA
sEcTtoN
3/6+
3. B COMMAND UNIT
3.8.1
Keyboard
The entire keyboard is constructed with a rubber
membrane
pad
with
built-in contacts.
The opposite contact
is made by the
mounting circuit
board implemented in
goJ-d
technology.
The keyboard rs designed as a 5 x B matrix and
interrogated
by
scanni-ng.
The five matrix columns
of the keyboard and the indicator
LEDs
are
controlled through the
serial-paralleI interface
SAA1061
(ICl).
The
SAAI06I
receives its infornation
from the
microprocessor through
the CBUS.
A
priority
encoder
processes
the key matrix row signals
and
supplies
them in coded
form to the microcomputer.
3.8.2
Display, meters
The
signal strength
is indicated by a 90'moving
coil instrument
that
features
a
dial cafibrated i-n dByF.
Center tuning
is indicated
by
a 72' moving coil
instrument.
A transflective LC drsplay indicates either the
frequency in
MHz,
the station name or
station number,
as
well as the
functions MUTING,
STEREO
or STORE. It is controlled by a series-
paralJ.el
j.nterf
ace LCD
driver
in multiplex 1:2
rnode.
The
LCD driver receives informatj-on through the CBUS from the
microprocessor. The
supply voLtage
of
the LCD is temperature-
compensated.
3.8.3 Level
control
The
STATION and STEREO thresholds
as
well
PHONES and VARIABLE OUTPUT
are adjustable
3.8.4 Remote
control
receiver
The
controlfed IR
receiver uses the Intermetall
circuit
package
TEA 1009.
The subsequent
pulse
shaper
supplies the
pulse
train
for
the interrupt
port
of the microcomputer.
as
the
fevels
for
with
potentiometers.