Circuit
Description
—
Type
575
+300
V
Fig.
3-3.
The
basic
Miller
Integrator
circuit
forms
for
linear
step
operation.
SWITCH POSITIONS
23232
32
32
1
2
,
60v
.... 1.1 .I..
I ....u
.-11—I I
A
J
z
100V
___ /
-1.5V
-----
l
—
B
a
_
j
—
1.9V
-------------
S
---------
K
V
------- ~
and
the resulting
plate
and
grid
wave-
a
negative
pulse
is
fed
to the
cathode of
V172A,
Cl
42
trans
fers
a
quantity
of
its
charge
to
Cl
77.
As
the
negative
in
put
pulse
returns
to its
base
level,
V172A
stops
conducting.
V172B,
however,
begins
to
conduct
heavily
to
restore
the
charge
on
Cl
42.
Because
the
Miller
integrator
keeps
the
voltage
at the
bottom
of
Cl
77
nearly
constant,
the
same
quantity
of charge
is
transferred
to
C177
with each
pulse.
The
voltage
steps
occuring
at
the
output
are
equal,
because
the
voltage
across
a
capacitor
is
directly
proportional
to
its
charge.
The
changing
charge
on
C142
is
an
important
part
of
the
generation
of
steps.
On waveform C,
point
"a"
(between
negative
pulses)
shows
the
left
end
of
Cl
42
to
be
+150
volts.
Waveform
B
shows
that
at
the
same
time,
the
junction
of
di
odes
V172A
and
V172B
is
near
ground.
The
charge
on
C142,
then,
must
be
about
150
volts.
As
a
negative
pulse
begins,
the
left
end
of
C142
is
driven
negatively
toward
+50
volts.
As
the
right
end
of
C142 tries
to
follow,
V172A provides a
current
path
for
Cl
77
and
its
charge
is
increased
as shown
on
waveform
A.
Since
the
capacity
of
Cl
77
is
about 7 times
as
large as
that
of
Cl
42,
the
increase
in
voltage
across
Cl
77,
15
volts
is
equal
to
1/7
of
the
decrease
in
voltage
across
C142.
Because
the
Miller
integrator
keeps
the
bottom of
Cl
77
at
a
constant
voltage,
the
15-volt
step
occurs
at
the
output
and
not at the
grid
of
V171.
Repetitive
Triggering
The
circuit
of
Fig.
3-5
is
used
to show the operation
of
the
Schmitt
Trigger
and
the
Hold-Off
Cathode
Follower.
Their
action
provides
a
repetitive display,
since they cause C-177
to
be
discharged
and
then
permit
the
formation
of
steps
to
proceed again
in
the
same
manner
as
described
previously.
For
our
purposes, we
think
of
the
Schmitt Trigger as
a
voltage-activated
switch.
In
its
operation,
the
entire
current
through
R156
in
the cathode circuit
is
shifted
from
one
sec
tion
of
VI55
to
the other.
When
one
side
of VI55 conducts
the
other
side
is
cut off.
Typical
conditions for conduction
are as
follows:
when
the
grid
voltage
of
V155A
is
above
—
42
volts,
V155A
conducts;
when
the
grid
voltage
of
V155A
is
below
—
58
volts,
V155B
conducts. When
the
grid
voltage
of
V155A is
within
the
range
from
—42 to
—
58
volts,
either
tube
section
may
con
duct,
but
not
both
sections.
The
output
of the trigger
circuit
is
at
the
plate
of
V155B.
The
voltage
at
this
plate
switches
between
zero
(V155B
cut
off)
and
a
negative
voltage
(V155B
conducting).
When
V155B
is
conducting,
the
diodes
V152A
and
V152B
are cut
off
because
their
plate
voltages are
more
negative
than
their
cathodes.
This
condition
permits
the
staircase
gen
erator
to
generate
a
stairstep
waveform
as
described
pre
viously.
As
the
output stairstep
waveform
rises,
the cathode
voltage
of
V143B
follows.
When
the
cathode
voltage
(and
the
grid
voltage
of
V155A)
reaches
—
42
volts,
the
Schmitt
trigger
will switch
to
its
other
stable
state;
that
is,
V155A
will
be
conducting
and
V155B
will
be
cutoff.
When
V155B
is
not conducting,
its
plate
voltage will
be
at
ground
potential,
permitting
diodes
V152A
and
V152B
to
con
duct.
As V152B conducts,
the
grid
of V171
is
clamped
at
ground
potential
causing
the
plate
voltage
to
fall
rapidly.
3-3
Summary of Contents for 175
Page 4: ...VWTICM OINltAlO TRANSISTOR CUM TRACfR UB l COUlClO r hokizoniai VCKIJ O lUnK Hix M Type 575 z ...
Page 6: ...NOTES ...
Page 26: ...NOTES ...
Page 48: ...NOTES ...
Page 54: ...Recalibration Type 575 C706 Fig 5 3 Left Side View 5 6 ...
Page 56: ...NOTES ...
Page 100: ...INPUT AMPLIF1E ...
Page 104: ...TYPE 575 TRANSISTOR CURVE TRACER ...
Page 108: ...OSCILLATOR 4OOV UNREG TYPE 575 TRAN5I5TOR CURVE TRACER AB ...
Page 115: ... 300 ...
Page 119: ...Type 175 Tent S N 570 PARTS LIST CORRECTION Change to Q233 151 0137 00 2N21U8 MIO 298 1165 ...