EasyManuals Logo

Tektronix 7613 User Manual

Tektronix 7613
224 pages
To Next Page IconTo Next Page
To Next Page IconTo Next Page
To Previous Page IconTo Previous Page
To Previous Page IconTo Previous Page
Page #79 background imageLoading...
Page #79 background image
Circuit
Description—7613/R7613
Service
Semiconductor
Q1401
is
a
programmable
unijunction
transistor
that
is
used
as
a
100-millisecond
pulse
generator.
Capacitor
C1391
and
resistor
R1392
are
the
timing
components
along
with
the
gate
voltage
divider
circuit.
Coupling
capacitor
C1406
couples
the
pulses
to
a
current
amplifier
(Q1409
and
Q1395).
The
pulses
are
direct
coupled
to
a
voltage
amplifier
(Q1411
and
Q1414).
In
the
variable
persistence
mode,
the
pulses
are
coupled
to
the
Storage
Target
Backplate
Amplifier.
In
the
Save
mode
of
storage,
the
pulses
are
coupled
to
the
flood-gun
cathodes
through
01425;
this
reduces
the
background
intensity
of
the
stored
display.
In
the
non-store
mode,
the
timing
elements
are
grounded
and
no
pulses
are
generated.
ERASE
TIMING
GENERATOR
Transistors
01336
and
01340
form
a
50-millisecond
monostable
multivibrator.
The
output
is
connected
to
transistor
Q1345
(for
inverting)
and
to
coupling
capacitor
C1347.
The
outputs
from
this
stage
are
called
T,
and
T,.
Capacitor
C1347
couples
the
output
signal
(T,)
to
the
base
of
transistor
01352.
Transistors
Q1352
and
Q1357
forma
10-millisecond
monostable
multivibrator.
The
output
signal
from
this
stage
is
called
T,
and
is
connected
to
coupling
capacitor
C1360,
which
couples
T,
to
the
base
of
transistor
Q1365.
Transistors
Q1365
and
©1369
form
a
400-
millisecond
monostable
multivibrator.
The
output
signal
is
called
T..
These
monostable
multivibrators
are
cascaded
to
provide
a
sequential
train
of
pulses.
See
Fig.
3-40
for
the
basic
block
diagram
of
the
Erase
Timing
Generator
and
idealized
waveforms.
The
pulses
are
connected
to
the
Storage
Target
Back-
plate
Amplifier
and
to
the
circuits
controlling
the
flood-gun
cathodes
and
anode.
Pulse
T,
turns
on
transistor
Q1423,
which
saturates
01425,
grounding
the
flood-gun
cathodes.
Pulse
T,
also
provides
a
sweep
lockout
pulse
that
goes
to
the
time-base
plug-in
unit
through
transistor
01432,
and
a
pulse
that
goes
to
the
Flood-Gun
Anode
Amplifier.
This
applies
a
positive
pulse
to
the
flood-gun
anode.
14
T2 T3
Q1336
Q1352
Hh
H
Q1357
LDS
Q1345
Q1365
yn
Q1340
Q1369
50
msec
n__
“TT
10
msec
T2
400
msec
T3
Le
Fig.
3-40.
Erase
timing
pulse
generator.
STORAGE
TARGET
BACKPLATE
AMPLIFIER
The
Storage
Target
Backplate
(STB)
operational
ampli-
fier
is
a
current-to-voltage
conversion
amplifier.
It
consists
of
transistors
01494,
01498, 01502,
and
Q1505.
The
level
control
and
the
level
preset
adjustment
provide
quiescent
control
over
the
STB
amplifier.
During
an
erase
cycle,
pulses
Ty.
14,
T,,
and
T,
are
generated.
Operation
of
the
Erase
Pulse
Generator
is
discussed
with
the
Erase
Pulse
Operator
circuit.
At
time
T,,
the
STB
amplifier
is
pulsed
with
a
negative
pulse
50
ms
in
duration.
This
negative
pulse
causes
a
high
3-52
positive
level
at
the
output
of
the
STB
amplifier.
At
time
T2,
transistor
Q1458
is
turned
on
for
10
ms
and
Q1462
is
turned
off.
When
transistor
Q1462
is
off,
CR1480
is
forward
biased
so
that
current
from
the
collector
circuit
of
Q1482
is
not
part
of
the
input
current
to
the
STB
amplifier.
This
reduces
the
output
voltage
of
the
STB
amplifier.
During
the
T,
pulse,
transistor
Q1453
turns
on
and
transistor
Q1467
turns
off,
allowing
current
from
the
collector
circuit
of
Q1467
to
go
into
the
input
of
the
STB
amplifier.
This
raises
the
output
voltage
of
the
STB
amplifier.
See
Fig.
3-41
for
idealized
waveforms.
7613

Table of Contents

Questions and Answers:

Question and Answer IconNeed help?

Do you have a question about the Tektronix 7613 and is the answer not in the manual?

Tektronix 7613 Specifications

General IconGeneral
BrandTektronix
Model7613
CategoryTest Equipment
LanguageEnglish

Related product manuals