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Tektronix 7613 User Manual

Tektronix 7613
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the
output
voltage
is
provided
by
+130
V
Feedback
Amplifier
0852,
and
+130
V
Series
Regulator
O850.
The
output
voltage
of
this
supply
is
connected
across
divider
R855-R856.
This
divider
provides
a
quiescent
level
of
about
+50
volts
at
the
base
of
Q852.
The
reference
level
for
this
supply
is
provided
by
the
+50-Volt
Supply
connected
to
the
emitter
of
0852.
If
the
output
of
this
supply
changes,
this
change
is
sensed
by
Q852
and
an
amplified
error
signal
is
connected
to
the
base
of
0O850.
This
error
signal
changes
the
conduction
of
the
+130
V
Series
Regulator
Q850
to
correct
the
output
error.
Fuse
F855
protects
this
supply
if
the
output
is
shorted.
However,
since
the
response
time
of
F855
is
slow
to
a
shorted
condition,
VR851
provides
additional
current
to
the
base
of
O850
to
protect
it
from
damage
due
to
over-voltage.
Diode
CR852
limits
the
reverse
bias
on
Q852
to
about
0.6
volt
when
F855
is
blown.
Graticule
Light
Supply
Power
for
the
graticule
lights
is
supplied
by
the
Graticule
Light
Supply.
Rectified
voltage
for
this
supply
is
provided
by
5
V
Rectifier
CR820-CR821.
Q835
operates
as
a
series
regulator
transistor.
Emitter
follower
Q829
determines
the
conduction
of
this
series
regulator
as
controlled
by
front
panel
GRATICULE
ILLUM
Control
R1095.
Current-
limiting
to
protect
this
supply
is
provided
by
0827.
Under
normal
operation,
divider
R830-R831-R833
sets
the
base
of
Q827
below
its
conduction
level.
However,
if
excess
current
is
demanded
from
this
supply,
the
voltage
drop
across
R837-R838
increases
until
Q827
comes
into
conduction.
The
collector
of
Q827
then
limits
the
conduction
of
this
supply
to
limit
its
output
current.
Divider
R822-R823
provides
a
sample
of
the
line
voltage
in
the
secondary
of
T801
to
the
plug-in
unit.
This
provides
a
line-frequency
reference
to
the
plug-in
units
for
internal
triggering
at
line
frequency
or
for
other
applications.
SIGNAL
OUT
BOARD
VERT
SIG
OUT
The
vertical
signal
is
selected
by
the
TRIG
SOURCE
switch.
The
vertical
signal
selected
is
applied
to
the
bases
of
a
differential
amplifier
Q606
and
O618.
A
single-ended
signal
is
taken
off
the
collector
of
Q618
and
connected
to
an
output
buffer
Q620.
CR621
and
CR622
provide
protection
against
a
high
voltage
inadvertently
applied
to
the
output
connector.
Circuit
Description—7613/R7613
Service
+
GATE
OUT
The
gate
signal
is
connected
to
a
comparator
circuit
Q662
and
Q666
through
resistor
R660.
From
the
com-
parator
the
gate
signal
is
connected
to
the
emitter
of
an
output
buffer
0672.
Gate
Selector
switch
connects
one
of
the
gate
signals
to
R660,
the
input
of
the
Gate
Amplifier.
Possible
gate
signals
are
MAIN
gate
and,
with
a
dual-sweep
time-base
unit,a
DELAY
or
an
AUXILIARY
gate
signal
can
be
selected.
CR674
and
CR676
provide
protection
against
a
high
voitage
inadvertently
applied
to
the
output
connector.
+
SAWTOOTH
OUT
The
sawtooth
signal
is
connected
to
the
Sawtooth
Amplifier through
R36.
Q631,
Q634,
and
0640
comprise
a
negative
feedback
amplifier
with
a
gain
of
two,
determined
by
the
ratio
of
feedback
resistor
R645
to
the
combined
input
resistance
of
R630
and
R63.
CR635
and
CR676
provide
protection
against
a
high
voltage
inadvertently
applied
to
the
output
connector.
READOUT
SYSTEM
The
Readout
System
in
the
7613
provides
alphanumeric
display
of
information
encoded
by
the
plug
in
units.
This
display
is
presented
on
the
CRT
and
is
written
by
the
CRT
beam
on
a
time-shared
basis.
Schematics
for
the
total
Readout
System
are
shown
on
diagrams
at
the
rear
of
this
manual.
The
definitions
of
several
terms
must
be
clearly
under-
stood
to
follow
this
description
of
the
Readout
System.
These
are:
Character—A
character
is
a
single
number,
letter,
or
symbol
which
is
displayed
on
the
CRT,
either
alone
or
in
combination
with
other
characters.
Word—A
word
is
made
up
of
a
related
group
of
characters.
In
the
7613
Readout
System,
a
word
can
consist
of
up
to
ten
characters.
Frame—A
frame
is
a
display
of
all
words
for
a
given
operating
mode
and
plug-in
combination.
Up
to
six
words
can
be
displayed
in
one
frame.
Fig.
3-24
shows
one
complete
frame
(simulated
readout)
and
the
posi-
tion
at
which
each
of
the
six
words
is
displayed.
3-31
7613

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Tektronix 7613 Specifications

General IconGeneral
BrandTektronix
Model7613
CategoryTest Equipment
LanguageEnglish

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