Circuit
Description—Type
114
Fig.
3-1. Type 114 block configuration for pulse output.
reduced
to
half its
normal
value
so
that
the
Period
Gen
erator can deliver twice
the
usual
number
of
output
pulses.
This
procedure
ensures
that
the period
indicated
by
the
PERIOD
switch
remains
valid for
square-wave
operation.
(When
external
triggering
is
used,
the period of
the
square
wave
is
twice
that
of
the
triggering
signal,
since
the
Width
Generator is
functioning
as
a
bistable
and requires
two
pulses
for
each
cycle
of
operation.)
In
the
Width
Generator,
the
ramp
circuit
is
disabled
by
D
196, which
means
that
the comparator
consisting
of
D
193,
Q
194,
and
Q184
is
not
used.
Resetting of
the
width
bistable
is
accomplished
by
applying
the
output
of
WIDTH
>
PERI
OD
light
driver
transistor
Q155
to
the
base
of
Q125.
At
the
instant
of
turn
on
when
operating
in
the
square
wave
mode,
D
177
reverse
biases
and
Q
1
74 is
biased
on.
Q1
74
turns
off
Q164
and
zero
biases
steering
diode
D136.
Under
these
conditions,
the
first
pulse
from
the
Period
Gen
erator
forward
biases
D
1
36
and
turns
off
Q
145.
Turning
off
Q
145
turns on Q1
55,
which
in
turn
cuts
off
Q215
and makes
Q205
the
conducting
transistor
in
the
bistable.
Turning
off
Q215
also
biases
Q224
into
conduction
which
switches
the
steering
circuit
so
that
D
1
61
becomes
zero
biased.
The
second
pulse from
the Period Generator is
steered
to
Q205,
switching
the
bistable
and
the
steering
circuit.
Thus
the
output
of
the
bistable
is
a
symmetrical
square
wave.
Trigger Output Circuit
Trigger
output
transistor
Q234
normally
operates
in
satura
tion
due
to
the
current
through
R232.
Whenever
the
sig
nal
selected
by
the
TRIGGER
switch
goes negative,
the
volt
age
change is coupled
through
C231
to
the
base
of Q234
and
momentarily
takes
it
out
of
saturation.
When
this
hap
pens,
the
collector voltage
of
Q234
rises
sharply until
it
reaches
≈
3
½
volts
and
forward
biases
catcher
diode
D236.
The
resulting
trigger
output
through
C236
is
about
80
nanoseconds
wide
and
is
limited
to
≈
+3
volts
into
an
open
circuit,
or
to
10
ma
into
a
short
circuit.
The
TRIGGER
switch
permits
selecting
the
edge
of
the
output
waveform
at
which
the
trigger
occurs.
By
setting
the
switch
to
TRAILING
EDGE,
the Type 114
may
be
used
as
a
delay
generator
with
the WIDTH controls
setting
the
amount
of
delay.
Output Amplifier
The
two-stage output amplifier
consists
of driver
transistor
Q244
and
the
parallel-connected
output transistors
Q254
and
Q264.
When
negative
output
pulses
are desired,
the
output transistors
are
connected
common
emitter
and
the
+25-volt
supply
is
connected
to
chassis
ground
displacing
the
circuit
board
common
ground
25
volts
negative.
When
positive
output
pulses
are
desired,
the
output
transistors
are
connected as
an
emitter
follower
and
the
common
point
is
connected
to
chassis
ground.
Polarity
switching
of
the
out
put
is
accomplished
by
the
AMPLITUDE
switch.
3-2
Содержание 114
Страница 3: ...Type 114 Type 114 Pulse Generotor ...
Страница 8: ...Operating Instructions Type 114 Fig 2 1 Front panel control Fig 2 2 Type 114 rear ponel 2 2 ...
Страница 10: ...NOTES ...
Страница 14: ...NOTES ...
Страница 16: ...Maintenance and Calibration Type 114 Fig 4 1 Equipment necessary for recalibrating the Type 114 4 2 ...
Страница 28: ...Maintenance and Calibration Type 114 Fig 4 20 Locations of electrical components 4 14 ...
Страница 30: ...Parts List Type 114 EXPLODED VIEW 5 2 ...
Страница 45: ...TYPE 114 PULSE GENERATOR ...
Страница 46: ...PULSE GENERATOR ...
Страница 47: ...TYPE IM PULSE GENERATOR c ...
Страница 48: ...SW282 POWER SUPPLY CMD OUTPUT AMPLIFIER 4 POWER SUPPLY ...
