Tandberg RC-20 Service manual
TANDBERG
Remote
Service
Control
Manual
:
Batr
oo
It
tl
RC 20
-tleJ'
s
ffi*"*om
Remote
r
ransmitter
Control
Remote
The
cordless,
RC
Control
20
infra-red
Tandberg
The
system
transmitter,
nected
the
The
aid
invisible
The
to
tape/cassette
RC
20
of
infra-red
to
transmitter
Unit
remote
tape
and
consists
and
a receiver
and gets
deck.
transmits
light
the
human
unit
RC 20
control
unit
to control
cassette
its
decks.
of
a battery-driven
supply
information
(IR
light)
eve.
RC
207
svstem
uses
the latest
which is
voltage
with
which
a
con-
from
the
is
E lectrical
-
The electronics
of two
push
the
-
The
device
-
When
transmitter
applied
-
The
and it
-
The IR
the
base of
description
circuit
buttons (A1-1)
IR
unit
heart of
SAB
the
to U1.
oscillator
given
is
output,
command
Q2.
in the
boards.
(A1-2).
the
transmitter
(U1).
3210
push
buttons
is activated
frequency
by Ll,
pin
signals
transmitter
one
board for
and
one
are operated,
and current
is
about
C2 and
8,
is now
are applied
consists
board for
is
a MOS
4Z kHz
C3.
active
to the
the
the
is
and
Battery
The
during
battery
hours.
tinuously
Mechanical
The
screws.
the
life
current
use
is 12
has
So
the
for
dismantling
transmitter
One
battery.
consumption
mA
approximately.
capacity
a
battery
about
of
these
of
17
hours.
is held
screws
will transmit
together
for
the
about
is
located
transmitter
The
mA
200
con-
by
two
under
-
Transistor
pin
8,
and the
of
CR4,
-
The
purpose
regulate
light-emitting
each
pulse.
NOTE
with diode
with CR4
flow
will
-
! The
through
de destroyed.
CR4,
which
will
flash
diodes
CRI -
is
a buffer
Q2
current generator
R8,
Q3,
the
transmitter
CR4
disconnected,
diodes
in
and R9.
of
the
current
current
diodes
disconnecte
CRI
is
a red
light-emitting
step with
CR4.
the output
through
to about
must
not
d. If
a
heavy
-
CR3
the
current
consisting
generator
the
infra-red
1.3
A
be
<tperate
it
is
opcrated
.r.l.r.rrt
and
thev
diocle,
through
IR,
is
irr
-ill
to
d
R
-
The
six
pulse
IR
signal
information
sequence
consists
bits.
An
is
given
of one
overview
in
table
start-bit
of
1.
and
the
ransmitter
RC 207
-
Receiver
RC 20R
-
Control
operated
Wind
and
Stop
Stop
and
Stop
and
Stop
and
Rewind
Record
Play
Wind
Rewind
Wind
Rewind
Play
(both)
sequence
Bit
(transmitter)
-1
It
LI
=Q
at the output
1O ms approx.
of
Table
Ul,
--{
pin
1
8
Logic
levels at the
outputs of
Ul
Logic levels
pin
No.:
connector
at
(receiver)
ABCD
0000
1000
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
0100
0010
1010
0110
0001
12457
11001
10111
10110
11011
01110
11110
11101
Receiver
Functional
The receiver has two main
-
One
from
which
a system
-
The
aid
deck
Timer is
power
chosen
unit
RC 20R
description
function is to convert
the transmitter to electrical
operate
second
other
of
goes over
to the tape
time.
the tape
of
command signals.
function is
controls)
Play
to
used. A Timer switches
deck automaticalll'
functions:
the IR light
signals
deck
according
select
(with
when a
on the
the
at a
to
whether the tape
or Record
to
E
lectrical
-
The
circuit
-
The receiver diode
IR
optical filter
visible
The
i00/120
lamps.
description
IR amplifier
board (A2-1)
light
and
the
which makes
light.
circuit is
Hz light from
This is
designed to
important
are often used near
light.
An incandescent lamp
of its power
of
CR1.
within the
located
is
in the receiver
CR1
is
diode
is equipped
since
strong artificial
to
sensitive spectrum
on the top
unit.
very
sensitive to
with an
it
insensitive
suppress
incandescent
tape
decks
radiates 30%
to
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