Operating
Instructions
—Type
575
Characteristics
of
the Base
Step Generator
The
largest
current steps
the
base
generator
can
supply
are 200
ma.
each.
Since
up
to
12
steps
are
available,
the
maximum
current this
supply
will
deliver
is
therefore
2.4
am
peres. Because
of
necessary
restrictions
on
the
size
of
the
power
source
for
the
internal
transistors
used
to
deliver
the
current
steps,
the
input
characteristics
of
the
power
transistor
under
test
must
be
such
that
the
base
to
emitter
voltage
does
not
exceed 5
volts
when
the
base
current
is
2.4
amperes.
The
minimum
source
resistance
of
the
step
generator
in
the
VOLTS/STEP
range
of
the
STEP
SELECTOR
switch
is
one
ohm
(SERIES
RESISTOR
set
at
1
ohm).
This
is
a
constant
mini
mum
source
resistance
irrespective of the
size
of
the
voltage
steps.
The
source
resistance
increases as
resistance
is
switch
ed
in
series
by
the
SERIES
RESISTOR
switch.
When
power
transistors
are
driven
into
the
high
base-cur-
rent
region,
their
input
resistance is
often
low
enough
to
cause
the
input
steps
to
become
non-uniform
in
size.
Under
these
conditions,
it is
best
to
check
the
uniformity
of
the
volt
age
steps
by
displaying
the
base
voltage
on
either
the
verti
cal
or
horizontal
axis.
A
quick
check
of
generator
loading
may
be
made
by
changing
the
setting
of
the
SERIES
RESIS
TOR
switch from
1
ohm
to
3.4
ohms
while
collector
charac
teristics are being
displayed. A
radical
shift
in
the
position
of
the
trace
displaying
the
highest collector
current would
indicate
a
low
input
resistance
and
the
possiblity
of
non-
uniform
voltage input
steps
in
the
1
ohm
position.
Functions
of
Controls and Switches
All
descriptions
given
below
presume
that
the
transistor
under
test is
in
the
grounded-emitter
configuration
and
that
the
power-line
frequency
is 60 CPS.
Base
Step
Generator Block
REPETITIVE-OFF-SINGLE-FAMILY.
In
the
REPETITIVE
position,
the
Base
Step
Generator
produces
stair-step
waveforms.
A
characteristic
curve
is
plotted
during
each
horizontal
portion
of
the
stair-step
waveform.
In
the
OFF position,
the
BASE
STEP
GENERATOR
is
disabled. The
SINGLE
FAMILY
position
is
a spring-return
position
which
permits
the
generation
of
one
stair-step
waveform
each
time
the
switch
handle
is depressed.
STEPS/FAMILY.
Determines
the
number
of
steps
in each
family
of
curves.
POLARITY.
Selects
the
polarity
of
the
stair-step
waveform
to
be
applied
to
the transistor under
test.
STEPS/SEC.
Selects
the
steps-per-second
rate
of
the
Base
Step Generator as well
as determining
whether
the
steps
occur
at
the
beginning or
at
the
end
of
each
curve.
SERIES
RESISTOR.
This
switch
functions
only
when
the
STEP
SELECTOR
switch is
in
the
VOLTS
PER
STEP
position.
It
per
mits
the
simulation
of
the
source
impedance
of
the
circuit
in
which
the transistor
under
test
is
to be
used.
The
SERIES
RESISTOR
may
also
be
used
as
a
protective
device
to limit
the
current
that
might
otherwise
be
inadvertently
applied
to
the
transistor
base.
STEP
SELECTOR.
Selects
the
magnitude
of
either
voltage
or
current-per-step
to be
applied
to
the
transistor
under
test.
STEP
ZERO.
The
STEP ZERO
control
permits
adjustment
of
the
Step
Generator
to
start
on
the
zero-current
or zero
volts
curve
of
the
display.
ZERO CURRENT
—
ZERO
VOLTS.
In
the
ZERO
CURRENT
position,
the
connection
to
the
base
of
the
transistor
under
test
is
broken.
The
curve displayed shows
the
open-base
characteristic
of
the
transistor.
In
the
ZERO
VOLTS
posi
tion,
the
base
is
grounded
to
permit
examination
of
the
zero-bias
characteristics.
Collector Sweep
Block
PEAK
VOLTS
RANGE.
Selects
appropriate
power
source
to
give
collector
sweep
voltage
and
current
range
indicated.
Operates
in
conjunction
with PEAK
VOLTS
control.
PEAK
VOLTS
APPROXIMATE.
Variable
autotransformer
in the
primary
of
the
collector
sweep transformer.
Operates
in
conjunction
with PEAK
VOLTS
RANGE.
CIRCUIT BREAKER.
Protects
the collector
sweep
circuit
from
excessive
overload
currents.
POLARITY.
Selects
the
polarity
of
the
collector
sweep
to
be
applied
to
the
transistor
under
test.
DISSIPATION
LIMITING
RESISTOR.
Selects
a
protective
series
resistor
for
the
collector
circuit
of
the
transistor
under
test.
This
resistance
may
be
used
as
the
collector
load
resistor
to simulate
operating
conditions
of
the
transistor
under
test.
Refer
to
chart
on
top
panel.
Vertical
Block
CURRENT
OR
VOLTAGE PER
DIVISION.
COLLECTOR
MA.
Selects
the
collector-current
of the
transistor
under test for
the
vertical
display.
Different
switch
positions
within
this
range
change
the
calibration
of
the
vertical
display
by
changing
the
value
of
an
internal
current-sampling re
sistance.
2X.
Pushbutton
switch
multiplies
each
current
step
by
2.
0.1X.
Pushbutton
switch
divides
each
current
step
by
10.
BASE
VOLTS.
Selects
the
base
voltage
of
the
transistor
under
test
for
the
vertical
display.
The
sensitivity
is
determined
by
the
resistance
of
an
attenuator
in
the
vertical
amplifier.
BASE
CURRENT OR BASE SOURCE
VOLTS.
Base
current
is
displayed
vertically
when
the
STEP
SELECTOR
switch
(BASE
STEP
GENERATOR)
is
in
the
MA
PER
STEP
range. The
cali
bration
of
the vertical
display is
that
indicated by the
STEP
SELECTOR
switch
except
that
it
is
also
in
milliamperes
per
major
division
as well
as
milliamperes per
step.
2-8
Содержание 175
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Страница 6: ...NOTES ...
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Страница 54: ...Recalibration Type 575 C706 Fig 5 3 Left Side View 5 6 ...
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Страница 61: ...O I Ui Fig 6 6 Simplified circuit diagram of Type 175 Transistor Curve Tracer High Current A dapter ...
Страница 100: ...INPUT AMPLIF1E ...
Страница 104: ...TYPE 575 TRANSISTOR CURVE TRACER ...
Страница 108: ...OSCILLATOR 4OOV UNREG TYPE 575 TRAN5I5TOR CURVE TRACER AB ...
Страница 114: ...234 VAC 117 VAC PRIMARY CONNECTIONS FOR 234VOLT OPERATION ___I TYPE 175 TRANSISTOR CURVE TRACER HIGH CURRENT ADAPTOR ...
Страница 115: ... 300 ...
Страница 117: ...TYPE 175 TENT S N 393 PARTS LIST CORRECTION CHANGE TO SW510 TRANSISTOR SELECTOR 260 636 M6983 664 ...
Страница 119: ...Type 175 Tent S N 570 PARTS LIST CORRECTION Change to Q233 151 0137 00 2N21U8 MIO 298 1165 ...
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