Datapulse 101 - Theory of Operation; General Description

SECTION III
THEORY OF OPERATION
3. 1 GENERAL DESCRIPTION
Refer to the block diagram for the following discussions.
A clock pulse (1 C) with a variable repetition rate is generated
by the rate oscillator and applied to the trigger multivibrator which
produces the system clock pulse (1 D) for the pulse generator. The
oscillator output is also applied to the advance trigger amplifier to pro—
vide a synchronous “zero" time reference trigger output for internally
triggered operations. When the rate oscillator is turned on by the
repetition rate selector in any of the six range positions, its output
governs the operation of the remaining circuits through its control of the
trigger multivibrator.
When
the
repetition
rate
selector
is
in
either
of
the
two
external
trigger
or
the
two
line
trigger
positions,
the
external
trigger
amplifier
is
turned
on
and
its
output
(1
B)
controls
the
system
clock
pulse.
No
advance
trigger
occurs
because
the
rate
oscillator
is
turned
off.
A sample of the ac line voltage is taken from the power trans-
former secondary for the line trigger positions. A pushbutton trips the
trigger
multivibrator
directly
for
one
cycle
of
output
when
the
repetition
rate switch selects single pulse operation.
The main output will be continuous in the non-gated mode of
operation
but
will
be
interrupted
and
will
occur
in
bursts
in
either
of
the
two
gated
modes
of
switch
$2.
The
AND
gate
permits
the
delay
multi—
vibrator
to
be
driven
continuously
by
the
system
clock
or
to
be
turned
on
and off by gate signals from the gate emitter follower.
In
the
synchronous
mode
the
external
gate
amplifier
controls
the
rate
oscillator
and
turns
it
on
and
off.
The
main
output
pulse
train
is
synchronized
with
the
leading
edge
of
the
gated
waveform
and
is
turned
off
at
the
trailing
edge.
In
the
asynchronous
mode
the
output
of
the
external
gate
amplifier
is
applied
to
the
gate
emitter
follower
to
control
the
delay
multivibrator
rather
than
the
rate
oscillator.
The
signal
from
the
gate
emitter
follower
gates
the
signal
from
the
trigger
multivibrator
through
the
AND
gate
to
the
delay
multivibrator.
This
permits
the
rate
oscillator
to
provide
a
continuous
output
of
advance
trigger
pulses
and
causes
the
output
pulse
train
to
begin
with
the
first
advance
trigger
after
the
gate
is
applied
and
to