Advertisement
F)
THEORY
OF
OPERATION
AND
BASIC
CIRCUITS
BLOCK
DIAGRAM
DESCRIPTION
Refer
to
the
Block
Diagram
(Fig.
3)
for
the
following
explanation.
The
instrument
is
triggered
by
either
an
internal
oscillator
or
an
external
source.
When
triggered
externally,
the
trigger
input
is
fed
into
a comparator
circuit,
which
has
a threshold
voltage
set
by
the
LEVEL
control
(for
further
details,
see
the
Threshold
Module
description).
The
output
of
the
comparator
is
a
TTL
pulse.
The
INT/EXT
switch
controls
a
gate
that
selects
either
the
internal
oscillator
or
the
output
of
the
threshold
comparator.
The
output
of
this
gate
leads
to
an
AND
gate.
The
second
input
of
the
AND
gate
is
the
TTL
complement
of
the
GATE
input,
so
that
when
the
GATE
input
is
TTL
low
(0V),
the
AND
gate
passes
the
trigger
pulses
and
inhibits
them
when
the
GATE
input
is
high.
At
this
point,
the
trigger
signal
is
split
into
two
parts.
The
lower
channel
drives
a one-shot
circuit,
which
delays
the
pulse,
which
is
then
buffered.
The
upper
channel
is
buffered
only.
When
in
the
DELAY
or
DOUBLE
PULSE
modes,
the
upper
channel
is
connected,
by
a
switch,
to
the
front
panel
SYNC
output.
In
the
ADVANCE
mode,
the
lower
channel
is
connected
instead.
The
two
channels
then
pass
through
the
double-pulse
circuitry.
When
in
the
ADVANCE
or
DELAY
modes,
both
signal
pass
unaltered.
In
the
DOUBLE
PULSE
mode,
the
upper
channel
is
unaltered,
but
the
two
input
channels
are
combined
to
create
a
new
signal
on
the
lower
channel,
yielding
a series
of
double
pulses.
When
in
the
ADVANCE
mode,
the
upper
channel
is
switched
in
to
drive
the
next
circuit
stage,
the
pulse
width
controller.
In
the
DELAY
or
DOUBLE
PULSE
mode,
the
delayed
lower
channel
drives
the
pulse
width
circuit.
The
output
of
the
pulse
width
stage
is
a TTL
pulse
whose
pulse
width
is
equal
to
the
pulse
width
of
the
instrument's
front
panel
output.
Advertisement
Need help?
Do you have a question about the AV-1010-C-NCSU and is the answer not in the manual?