INSTRUCTION MANUAL
MODEL 427
CURRENT AMPLIFIER
0 1975,
KEITHLEY INSTRUMENTS, INC.
CLEVELAND, OHIO, U.S.A.
DOCUMENTNUMBER29103
CONTENTS
MODEL 427
CONTENTS
1.
GF,Ng3,&.L DESCRIPT~ON-------------------------------.--------
1
2.
OPERATION--------------------------------------------------
4
3.
APPLICATIONS-----------------------------------------------
9
4.
ACCESSORIES------------------------------------------------
10
5.
ClRC"IT
12
6.
REp~Cp‘&LE
7.
CALIBRATION------------------------------------------------
DESCRIPTION----------------------------------------
PARTS------------------------------------------
SCNEMATICS----------------------------------------------------
17
26
33
1074
ILLUSTRATIONS
MODEL 427
ILLUSTRATIONS
Figure
1074
No.
Title
1
Front
panel.
2
Front
pane1
3
Rear
4
shunt
5
Effect
__-___---___-_____-___________________
6
Compensation
6b
Extended
Frequency
7
Fee&a&
Method.
8
Input
9
Bandwidrh
9b
Effect
of
filter
on Noise
9,
Effect
of
Input
Capacitance
Controls.
Panel
Method
3
Voltage
Shunt
4
----------------------
Capacitance.
Response.
4
---------------
5
----------------------
5
_--__-_-__________-_______________
N&se.
of
-----------------__------
capacitance.
for
3
-
Measurement,
Shunt
1
________--______-____________
Controls.
of
Page
6
-------------___--------------
Feedback
System.
Compensafian.
6
---------------------
spectrum.
7
--------------
on Noise.
7
-------------
7
10
Frequency
11
Plot
12
Block
Diagram
13
Filter
circuit.
14
power
15
current
lb
COmpOnent
Layout
- PC-291.
------------------------
13
17
component
Layout
- pc-290,
-----------------___----
14
18
component
Layout
-
pc-2?39. ---------_------___-____
15
19
COmpOnenf
Layout
-
P&292. ---------------__------
15
20
chassis
- Top vie”.
21
Chassis
Assembly
22
Bottom
23
Measurement
of
Input
24
Measurement
of
Rise
25
Measurement
of
Filter
of
---------_____--_-__-------
Noise-Improvement
s”pp~y
of
a High-Speed
Current
_____ -__-__
Amplifier,
------_______--_-__-_______________
Regulator.
suppression.
CO”er
__-
Contours.
7
--------------------------------------__----------------
------------___--------------- Exploded
Assembly.
“few.
Time.
Rise
Drop.
12
13
13
13
16
-----------------
-------------------------Voltage
--
9
19
19
----------------
27
-------_--_____-___-_____
28
Time.
------------------
29
iii
MODEL 427
SPECIFICATIONS
SPECIFICATIONS
RANGE: 10’ to 10” volts/ampere
in eight decade ranges.
(10-13 ampere resolution
to 10.” ampere full output).
OUTPUT: *10 volts at up to 3 milliamperes.
OUTPUT RESISTANCE: Less than 10 ohms dc to 30 kHz.
OUTPUT ACCURACY: 12% of reading to the lo9 vattsl
ampere range, +4% of reading on the 1O’O and 10”
volts/ampere
ranges exclusive of noise. drift and current
offset.
RISE TIME (10% to 90%): Adjustable
in lx and 3.3x steps
from “Fast Rise Time” listed below to 330 rnsec.
NOISE VS. RISE TIME’:
FAST RISE TlML
I
STABILITY:
Current offset doubles per 10°C above 25°C.
Voltage drift is less than 0.005% per “C and less than
0.005%,- ,,er da” of full outDut after l.hour warmur,.
OFFSET CURRENT: Less than lQLz am&e
at 25”C’and
up
to 7001, relative humidity.
CURRENT SUPPRESSION:
lo-lo ampere to 10-a ampere in
eight decade ranges with 0.1% resolution
(lO.turn
poten.
tiometer).
Stability is +O.Zo/. of suppressed
value per “C
bO.Z% per day.
INPUT VOLTAGE DROP: Less than 400 /.IV for fullaxle
output on the 10” to 10” volts/ampere
ranges when
properly zeroed.
EFFECTIVE INPUT RESISTANCE: Less than 15 ohms on the
10” and 105 volts/ampere
ranges. increasing
to less than
4 megohms on the 10” volts/ampere
range.
MAXIMUM INPUT OVERLOAD: Transient:
1000 volts on any
range for up to 3 seconds using a Keithley (or other 10
mA-limited)
highaoltags
supply. Continuous:
500 volts
on the 10” to 1O’voltsjampere
ranges, decreasing to ‘ZOO
an the 10”. 70 on the lo5 and 20 volts on the 10’ volts,
ampere ranges.
OVERLOAD INDICATION:
Lamp indicates
pre-filter
or post.
filter overload.
DYNAMIC RESERVE: 10 (20 dB).
CONNECTORS:
Input:
(Front)
ENC. Output:
(Front and
Rear) BNC.
POWER: 90.125 or 180.250volts
(switch selected), 50.60 Hr.
5 watts.
DIMENSIONS; WEIGHT: Style M 3%” half.rack, overall bench
size4’~highx8%‘widex12L/a”deep(100x217
x310 mm).
Net weight, 7 Ibs. (3.0 kg).
i”
1074
MODEL 427
GENERAL DESCRIPTION
SECTION
1.
GENERAL
l-1.
GENERAL;
The Model 427 Current
Amplifier
is a
high-speed,
feedback-type
amplifier
with
particular
features
useful
for automated
semiconductor
testing,
mass spectrometry,
and gas chromatography
applications.
DESCRIPTION
C. Built-in
Current
Suppression.
Small changes
in
the signal
level
can be measured
since
large
ambient
current
levels
can be easily
suppressed.
d. Overload
assured
since
l-2.
are
Accurate
measurements
are
automatically
indicated.
FEATURES.
a. Wide Dynamic
low-noise
operation
current
levels.
Range.
Selectable
important
when
b. High Speed.
out of a 10sSZpere
rise
time.
Typical
resolution
is 20 picoamperes
signal
with
a 100 microsecond
0471
Indication.
overloads
rise
times
permit
resolving
small
e. Variable
Cain.
The GAIN Switch
is designated
in eight
gain positions
from lo4 to 1011 volts
per
ampere - therefore
gain adjustment
is straight
forward.
f. Variable
Kise Time.
Optimum response
can
selected
for each gain setting
since
a separate
TIME switch
is provided
on the front
panel.
be
RISE
1
GENERAL DESCRIPTION
MODEL 427
Front
TABLE 1-l.
Controls
and Terminals
Panel
Functional
PUSH
Power
GAIN Switch
RISE
TIME
Switch
Controls
(S302)
sets
(5201)
power
gain
in
Sets rise
(5101)
Description
to
Paragraph
instrument.
2-4,
al
2-4,
a2
2-4,
a3
2-4,
a4
2-4,
a5
2-4,
a6
zero.
2-4,
a7
connection.
2-3,
a
2-3,
b
2-5,
d
Volts
time
per
ampere.
Fn milliseconds.
SUPPRESSION
MAX AMPERES Switch
FINE
Control
POLARITY
Switch
Receptacle
Sets
(5304)
Adjusts
(5202)
Input
~ OVERLOAD Indicator
Line
Switch
Terminal
(5301)
Power Receptacle
Fuse
Panel
0lJTPuTReceptacle
(5103)
Output
suppression.
connectFon.
overload
condition.
TABLE 1-2.
Controls
and Terminals
Description
instrument
Connection
Type
(F301)
source
Functional
Sets
(P305)
of
output
Indicates
(DS302)
Rear
or
suppression.
Output
(5102)
suppression.
polarity
(R235)
OUTPUT Receptacle
Control
maximum
Adjusts
(R333)
ZERO ADJ Control
INPUT
Sets
(S303)
to
for
line
3AG Slow-Blow,
117V or
Paragraph
23411.
power.
117V @ l/4
234V @ l/S
2-4,
b
2-3,
c
2-3,
b
A (w-17)
A (w-20)
connection.
WARNING
Using a Line Power Cord other than the one supplied
with your instrument
may result
in an electrical
shock hazard.
If the Line Power cord is lost or
only with Keithley
Part No. CO-7.
damaged, replace
0878
MODEL 427
GENERAL DESCRIPTION
,----SUPPRESSION-,
GAIN
SWITC
S20
INPUT
5202
FINE
ADJUST
ZERO ADJ
R235
FIG"RF
OVERIDAD
DS302
2.
want
Panel
POLARITY
SWITCH
.
Power
S302
Controls.
I
FIGURE 3.
0471
Rear
Panel
Controls.
P
OUTFW
5102
OPERATION
MODEL 427
SECTION
2-1.
2.
MEASUREMENT CONSIDERATIONS.
Prom this
equation
it is irmnediately
apparent
that
the
m%QB”rement
of emall
current
=equi=es
large
values
of
R, i.e.,
high impedance
levels.
Howwee,
thfe
gives
difficulties
for meas”=ements
requiring
wide bandwidths
because
of the RC time constant
associated
with
a
high-megohm
resistor
and even a few picofarads
of circuit
capacitance.
Figure 4 shows a c”==ent
s”“=ce
generating
a voltage
across
a parallel
RC.
The frequency response
of this
current
measurement
is limited
by the RC time constant.
Figure 5 shows this response
end the -3 dB p”int
“CC”=B at a frequency
The DleasUrement
of
a.
Current-Detection
Devices.
‘small
electrical
c~rrent8
has been the basis
for a
number of instrumental
methods
used by the analyst.
Ion chambers,
high-impedance
electrodes,
many forms
of ch=“metog=aphic
detectors,
phototubes
and multipliers are coaronly-used
t=ansduce=a
which
eequire
the
measurement
of small
currents.
Devices
used for this
measurement
a=e often
called
electraaeters.
b..
In any measurement,
if e”“=ce
noise
greatly
exceeds
that
added by
the inst=“mentatian,
optimization
of instrumenteti””
When source
noise
approaches
theoretis unimportant.
ical
minimum,
optimization
of instrumentation
characteristics
becomes imperative.
TO determine
the category into which
this
meas”=ement
falls.
the researcher
needs t” be familiar
with
the characteristics
which
impoee theoretical
and practical
limitations
on his
a=e familiar
with
the
me*surement
. Most researchers
theoretical
limitations
present
in voltage
measueements
The noise
inceeases
with
8”“=ce
realstance,
and the
familiar
equation
for the mean-square
noise
voltage
is
q
=
4kTRAf
OPERATION
Eq.
a=e contradictory
Lor* noise
and high speed, therefore,
requirements.
TO optimize
a current-measuring
system,
techniques
must be used which
obtain
high speed “sing
high-impedance
devices.
C.
1
whe=e k is the Boltzma””
Constant,
T ia the absolute
temperature
of the s”“=ce
resistance
R, and Af is the
the 3 dB bandwidth
for a
noise
bendwidth(
3 times
single
RC rolloff.)
In the case of cureent
measurements it Is more appropriate
to consider
the noise
current
generated
by the ~l”“=ce
and load resistances.
The mean squaee noise
c”==ent
generated
by a resistor
is given
by Eq. 2.
Hiah
Speed
Methods.
1.
High epeed can, af c”“=se,
be obtained
in .
shunt-type
meae”=eme”t
by “sing
a low value
for the
shunt resist”=.
As pointed
““t
above,
such a srmll
resistor
value
int=ad”ces
excessive
noise
into
the
meQ8”rement.
2.
A second method to achieve
bandwidth
is to
keep R large,
to accept
the frequency
roll-off
starting
at F”, and t” change
the frequency
eesponae
of the voltage
amplifier
a8 ehown in Figure
6a.
The
combined
effects
of the RC time c”“sta”c
folloved
by this
amplifier
is shown in Pigure
6b and it is
seen that
the frequency
response
of the c”==ent
measurement
has been extended
to Pl.
The frequency
at which
the amplifier
gain sta=‘ts
to increase
must
be exactly
equal
t” the frequency
F” determined
by
the RC time c”nstant
in order
for this
approach
t”
result
in a flat
frequency
respanse.
Therefore,
FO
FIGURE 4.
I
In the shunt method c”=re”t
is measured
the voltage
drop ac=“ee
a resistor.
by
FIGURE
5.
The frequency
respanse
of
1s limited
by omnipresent
LOG FREQUENCY
the shunt method
ahunt capacitance.
0471
MODEL 427
OPERATION
this
oethad
is ueeful
only
far application*
where
the shunt capacitance
C is constant.
Aaide
from
thin
drawback
this
is * 1eSitimste
approach
which
is being
wed
in low-noise,
high-speed
currentmeesuring
applicatians.
In addition
to current
noise
in the *hunt
and in the amplifier
input
stage,
B
maJor source
of noise
in this
system *ri***
from
the voltage-noise
generator
ssaociated
with
thb input atage
(reflected
a* current
noise
in the shunt
resistor)
caused by the high-frequency
peeking
in
the following
stages
of amplification.
More will
be
said about
this
in the discussion
on noise
behavior.
3.
A third
method used for speeding
up * current
measurement
asas guarding
techniques
to eliminate
the effects
of capacit*nces.
Unfortunately
only
certain
type*
of capacitance*,
such ** cable
cap=itances,
can be conveniently
eliminated
in this
To eli,r,inate
the effect
of parasitic
c*p*cmanner.
itences
associated
with
the *ource
itself
became*
very
cumbersome
and m*y not be feasible
in many inThe major
*ourc**
of noise
in this
*“*tern
stsnces.
*re identical
to those mentioned
in the second
system.
4.
A fourth
circuit
configuration
combines
the
capability
of low-noise
and high-speed
performance
with
tolerance
for varying
input
C and eliminate*
need for separate
guard by making
the ground
plane
*n effective
guard.
This is the current-feedback
technique.
This technique
gives
* typical
improvement of 3 over shunt
technique*.
Again,
the major
sources
of noise
are identical
to those mentioned
in the second system.
d.
Noise
in Current
Measurements.
Noise
forms *
b*aic
limitation
in *nv hinh-speed
current-measurinn
system.
The shunt
*y&m
give;
the simplest
curren;
measurement
but does not give
low-noise
performance.
A properly
designed
feedback
*y*tem
gives
superior
noise
- bandwidth
performance.
Noise
in these
two
systems
will
be discussed
next.
1.
Noise
Behavior
of the Shunt System.
High
speed end low noise
*r* contradictory
requirements
in any current
meesurement
because
*orw capacitance
is always
present.
The theoretical
performance
limftetion
of the shunt
*yetem
c*n be calculated
**
The rms
resistance
thermal
R is
noise
given
current
by
FIGURE
0471
6.
F>
generated
i
UPP
=
2 x 10-9
F,
4
(.f)
of * parallel
SC
snd the eignal
hand1/(2nRC).
For practical
is taken
88 5 times
the
noise
current
can now
Eq.
F
5
In practice,
e typical
value
for shunt cape.cit*nce
is 100 picofarads.
With this
value
the following
rule-of-thumb
is obtained.
The lowest
ratio
of
detectable
current
divided
by signal
bandwidth
using
*hunt-techniques
is 2-10-14
ampere/Hertz
for B peakto-peak
signal-to-noise
ratio
equal
to 1.
A corollary far this
rule-of-thumb
expresses
the noise
current
in term* of obtainable
risetime
(lo-SO%
risetime tr = 2.2 RC).
The lowest
product
of detectable
current
and risetime
using
shunt technique*
is 7 x
lo-l5
ampere seconds.
In this
derivation
it has been
assumed that
the voltage
amplifier
does not contribute noise
to the measurement.
2.
Noise Behavior
of the Feedback
System.
There
are three
*ource*
of noise
in the feedback
system
that have to be looked
at closely.
The firat
two,
input-stage
shot noise
and current
noise
from the
mea*urinS
resistor,
are rather
straight-forward.
The
third,
voltage
noise
from the input
device
of the
amplifier,
cau*e*
*ome peculiar
difficulties
in the
measurement.
Any resistor
connected
to the input
injects
white
current
noise
(Eq. 4).
In the circuit
of Figure
7 the only resistor
that
is connected
to
the input
is the feedback
resistor
R. As in the
shunt system,
R must be made large
for lowest
noi*e.
Beceuse
this
noise
is white,
the total
contribution
can be calculated
by equ.,ting
Af to the equivalent
noise
bandwidth
of the system.
The second
*ource
of
noise
is the current
noise
from the amplifier
input.
This component
is essentially
the shot noise
asaociared with
the gate leakage
current
(io)
of the input
device.
Its
rms value
equals
...
F,
LOG FREQUENCY
LOG FREWENCY
ny tailoring
the frequency
response
of the
amplifier
(Pig.
6a) the frequency
response
of the shunt method c*n be extended.
by *
Eq.
The equivalent
noise
bandwidth
combination
is Af = 1/(4RC)
width
(3 dB bandwidth)
F, =
purposes
peak-to-peak
noise
ml* value.
The peak-to-peak
be written
a*
FO
FO
(in)
FIGURE
6b.
Extended
frequency
response.
OPERATION
MODEL 427
T;; = J-zTpwhere e is the electronic
charge.
The contribution
of this
noise
generator
is also white.
N*t only do
these
two noise
sources
generate
white
current
noise,
the noise
in a given
bandwidth
is also
independent
of the input
capecitence
C.
The mejor
source
of
noise
in e feedback
current
meesurement
is the noise
contribution
aseocisted
with
the voltage
noise
of
the input
amplifier.
The voltage
noise
ten be represented
by a VOltage
noise
generator
(0,)
et the
emplifier
input
es shown in Figure
8.
This wise
generator
itself
is assumed to be white.
However,
its
total
noise
contribution
to the current-measuring
system
is not white.
Inspection
of Figure
6 will
reveal
that
et low frequencies
P large
em*u*t
of feedbeck ie applied
around
the voltage
noise
source
{en).
However,
the SC combination
ettenuetes
the highfrequency
components
of V,,t
so that
no feedback
is
present
et high
frequencies.
Thus,
the noise
contribution
to the output
voltage
V,,t
from the valtage noise
source
a* is no longer
independent
of
frequency.
The noise
is “colored”
and increases
in
intensity
for ell
frequencies
higher
than F,.
The
resulting
noise
spectrum
is shown in Figure
9b. The
tote1
system noise
is related
to the are* under
Because
the logarithm
of frequency
is
this
curve.
plotted
on the horizontal
axis,
the eree under
the
curve
et higher
frequencies
represents
e significantly
larger
amount of noise
then e similar
eree
For comparison,
Figure
9a show
*t low frequencies.
the frequency
response
of the current
measuring
Figure
9e ia identical
to Figure
6b.
It is
system.
interesting
et this
point
to compare
this
noise
spectrum
with
the frequency
response
of the voltage
amplifier
in Figure
4 es shown in Figure
6a.
A voltage noise
eouec.e et the input
of the amplifier
would
generate
a noise
spectrum
according
to the amplifier
frequency
response
as shown in Figure
6a.
The noise
spectrum
of such e system,
then,
is identical
to the
noise
spectrum
of the feedback
system as given
in
This illustrates
the well-known
fact
Figure
9h.
that
signal-to-noise
performance
of a measurement
cen**t
be improved
by feedback
techniques.
At the
high-frequency
end the voltege
noise
is limited
by
the frequency
FA which
is the high-frequency
rolloff
point
of the operational
amplifier.
It should
FIGURE
6
7.
Beslc
circuit
back method.
configuration
for
the
feed-
he noted
that
even though
the useful
bandwidth
of
the system extends
only
t* Fl,
there
era noise
components
of higher
frequency
present.
To obtain
best widebend-noise
performance,
these high-frequency
noise
components
have to be removed.
This ca* be
achieved
by adding
a low-pass
filter
section
following the feedback
input
stage.
If the band-pass
of
thin
low-pass
filter
is made adjuetable
this
filter
can nerve
the dual purpose
of removing
high-frequency
noise
end of limiting
the signal
bandwidth
of the
system.
2-2.
THEORY OF OPERATION.
8.
Current
Feedback
Technique.
The basic
circuit
configuration
used in the current-feedback
technique
In this
configuration
the
is shown in Figure
7.
current-measuring
resistor
R is placed
in the feedback
loop of e* inverting
emplifier
with
a gain of A*.
The
frequency
response
obtained
with
this
circuit
is identical
to thet
s+nvn in Figure
6b.
F* agein
is the
frequency
associated
with
the RC time constant:
F,
=
SE
The frequency
frequency
fl
response
where
F,
=
AoF,
of
the
syetem
is
extended
Eq.
6
t*
a
Eq.
7
Note that
the frequency
rerponse
is automatically
flat
without
heving
to match break
points.
However,
the
total
bandwidth
of the system
(Fl)
is still
limited
by the value
of the ahunt capacitance
C across
the
This
improved
frequency
response
of the feedinput.
back technique
avoids
the use of low values
for R
which
could
generate
exceesive
current
noise.
.
b.
Refinements
of the Feedback
System.
A major
difficulty
of the feedback
system ariees
from shunt
capacitence
esaociated
with
the high-megohm
resiaeor
R
If the shunt cepacitence
acroes
in the feedheck
path.
the resistor
is CFr then the bandwidth
(FF) of the
system
is determined
by the time COnstent
RCF:
FIGURE
8.
The voltage
noise
associeted
with
the amplifier
input
device
is en important
eourc~
of noise
in the high-speed
feedback
syatew
0471
MODEL 427
FIGURE
9.
OPERATION
The bendwidth
of the high-speed
feedback
system
(Fig.
9a) ten he limited
by using
e filter
with
either
e -6 dB/actave
or a
-12 dB/octave
roll-off.
The effect
of the
filter
on the noise
spectrum
is showwin
Effect
of input
capacitance
on
Fig.
9h.
noise
is shown in Fig..9c.
FIGURE
FF
FIGURE 9c.
0471
Effect
Effect
of
of
filter
input
on noise
capacitance
spectrum.
on noise.
Frequency
compensation.
1
2 nllcp
Eq.
A slight
modification
of the feedback
loop can correct
this
problem
es shown in Figure
10.
If the time constant
RlCl
is made equal
to the time constent
R.CF,
it CB* be shown that
the circuit
within
the dotted
line
behaves
exactly
es a resistance
R.
The matching
of time constants
in this
cese does not become e drawbeck because
the copscitances
involved
era all
constant
and not effected
by input
impedance.
C.
FIGURE 9b.
=
10.
-12
dB/actave
Filter.
1.
Theory.
To obtain
optimum widehand
noise
perfomence
e filter
with
e single
high-frequency
roll-6 dB/octave)
is not sufficient
end -12
off
(i.e.,
The effect
of e -6 dB filter
dB/octeve
is required.
is shown in Figure
9a end h.
The filter
is used to
limit
the system bandwidth
to a frequency
F2, smaller
then Fl.
The effect
af this
filter
on the noise
spectrum
is shown in Figure
9b.
It ten be seen that
there
ace egain high-frequency
noise
components
above
F2, the useable
bandwidth
of the system.
These can
he eliminated
by using
e filter
with
e -12 dB/octave
roll-off.
The result
of such .a filter
on noise
performance
is also shown in Figure
9b.
2.
Model 427.
The input
smplifier
18 followed
by
en adjustable
low-pass
filter
having
e -12 dB/octeve
roll-off
end a valtage
gain of 10X.
The voltage
gain in the low-pass
filter
avoids
premature
overloading
in the input
amplifier
which
ten be seen es
fallows.
The maximum output
voltage
V,,t
is $10
The maximum signal
level
et the input
of the
volts.
low-pass
filter
is,
therefore,
+l volt.
At this
point
in the circuit,
wide-band
noise
could
still
be
present
end exceed
the l-Volt
signal
level.
The
voltege
gain of 10 in the filter
allows
the total
pre-filter
wide-hand
noise
to exceed
the full
scale
signal
by e factor
of 10 (20 dB).
The frequency
response of this
filter
is edjustahle
for variable
“damping”
control.
7
OPERATION
2-3.
MODEL 427
CONNECTIONS,
2-5.
8.
The input
receptacle
(5202)
is e SNC
Input.
type which metes with
coaxial
cables
such es Keithley
Models
8201 end 8202.
The inner
contact
is circuit
high.
The outer
shell
is low or chassis
ground.
b.
Output.
(5102 on the
era BNC type*
end the outer
Two outp,ut
receptacles
*re provided
front,
5103 on the reer
panel).
These
where
the inner
contact
is output
high
shell
is chassis
ground.
C.
Power Input.
The power receptacle
rear panel
is a 3-prong
connector
which
Keithley
pare number CO-6 line
cord.
2-4.
(P305)
on the
metes with
OPERATING
8.
Gain.
The gein of the Model 427 is defined
in
terms of volts
per *“pare.
Since
the output
level
is
10 volts
for e full
scale
input,
the gain could
also
be expressed
e* sensitivity
in emperes
referred
to the
input
BS in Table
2-1.
Vout = - (Iin
x GAIN)
Eq. 9
Gain
GAIN
Setting
Sensitivity
Feedback
Resistor
103
104
105
106
107
108
109
1010
Front
Panel.
1.
Power Switch
“PUSH ON” (5302).
This switch
controls
the line
power to the instrument.
‘The
switch
is a special
pushbutton
type with
“Power On”
indicated
by a self-contsined
pilot
lamp.
b.
Rise Time.
is listed
in the
These rise
times
switch
is set to
2.
GAIN (VOLTS PER AMPERE) (S201).
This switch
sets the overall
gain in eight
positions
from 104
to loll.
A “ZERO CHECK” position
permits
adjustment of zero offsets.
3.
RISE TIME
the lo-90%
rise
300 milliseconds(for
Switch
(5101).
This switch
sets
time in 10 positions
from .Ol to
the filter
section
only).
4.
SUPPRESSION (MAX) Switch
(S303).
This switch
sets the maximum current
suppression
in eight
pasiis set
tions
from lo-10
to 10-3 A.
When the switch
to “OFF” the current
suppression
circuit
is disabled.
5.
SUPPRESSION (FINE)
control
(~333).
This control
permits
adjustment
of suppression
with
0.1%
resolution.
6.
SUPPRESSION (POLARITY)
switch
set*
the polarity
of
(referred
to the input).
Switch
(S304).
This
the current
suppression
7.
ZERO ADJUST Control
(R235).
This control
mits adjustment
of zero offset
through
the u*e
OVERLOAD indicator.
b.
Rear
1.
perof the
Panel.
Line
either
Voltage
117 or
Fuse
117V:
234V:
8
or
CONTROLS.
a.
for
CONSIDERATIONS.
Switch
(S301).
234 V operation.
RequirP.ment*
1/4A
l/SA
3AG,
Keithley
Keithley
Sets
Sla-Slo
No.
No.
F”17
F”-20
instrument
Switch
GAIN
Setti”g
104
105
106
107
1 10;
1oy
1010
loll
TABLE 2-l.
Referred
to
the
Input
Full
Scale
sensitivity
(Amperes)
1
1
1
I
1
1
1
1
x
x
x
x
x
x
x
x
10-3
10-4
10-5
10-6
10‘7
10-g
10-9
10-10
Full
Scale
Output
(Volts)
10
10
10
10
10
10
10
10
The rise
time for each gain setting
specifications
a* “FAST RISE TIME”.
are obtained
when the RISE TIME
the positions
indicated
in Table
2-2.
Settings
Rise
Time
15
15
15
40
60
220
400
1.5
ps
us
I*8
us
ps
&Is
“S
ps
TABLE 2-2.
for “FAST
RISE TIME”
RISE TIME
Setti”g*
DYlWl”iC
Range
.Ol “S
.Ol ms
.Ol “S
.03 “9
.03 ms
.l
“S
.3 ms
1 ms
2000
2000
2000
2000
800
400
200
100
J
c.
Suppressian.
Current
suppression
is provided
in
the Model 427 for suppression
of input
currents
up to
By suppressing
background
currents,
smell
10e3 amperes.
variations
in e larger
signal
can be observed.
Currents
of either
polarity
can be suppressed.
To suppress
an
input
current
the SUPPRESSION should
be *et to supply
e current
of apposite
polarity.
The FINE control
permits
adjustment
up to 1.5 times
the MAX setting.
d.
Overloads,
The overload
sensing
circuit
detects
en overload
et two places
in the circuit:
before
end
after
the “RISE TIME” filter
circuit.
The OVERmAD
lamp (DS302)
will
indicate
whenever
the voltsge
sensed
ia greater
then full
scale
regardless
of the RISE TIME
setting
or the frequency.
a.
Zero Adjust.
The ZERO CHECK po*ition
grounds
the
the input
of the instrument
and co”“ert*
the cuerent
amplifier
to a high-gain
voltage
amplifier.
The amplified
offset
voltage
will
turn
on the OVERLOAD indicator
whenever
the input
voltage
offset
exceeds
5100 t0l.
Therefore
the ZERO control
should
be adjusted
so that
the OVERLOAD indicator
is off when in ZERO CHECK mode,
yielding
the specified
input
voltage
drop.
APPLIChTIONS
MODEL 427
SECTION
3.
APPLICATIONS
3-3.
NOISE-IMPROVEMENT
CONTOURS.
The sensitivity
and speed of the Model 427 (for
either
d-c or a-c
measurements)
can be compared
to the best perfarmante obtainable
with
the shunt method of measuring
current.
The best “noise-risetime”
product
that
can be achieved
for d-c measurements
(with
100 pF
shunt capacitance)
in a shunt
system
is 7 x lo-15
ampere-seconds.
However
the feedback
system achieves
2 x lo-l5
ampere-seconds
(also
with
100 pF shunt
capacitance).
When used in a-c narrowband
systems
(lock-in,
etc.)
the-degree
of improvement
is a function
of shunt capacitance
and operating
frequency.
The achieveable
imprownene
over the shunt method
can be plotted
in a graph similar
to a set of noise
contours.
Figure
11 shows the measured
impravemene
(negative
dB) that
can be obtained
with
the Model
427 at a given
frequency
and shunt capacitance
when
compared
to an ideal
(noiseless)
amplifier
Fn a shunt
system.
,
3-1.
CURRENT~MEASURING SYSTEM.
The typical
current
meaeuring
system consists
of a current
source,
a current
amplifier,
and a monitoring
device,
The current
source
could
include
an ion chamber,
photomultiplier,
The current
amplifier
or other
high-impedance
device,
such as the Model 427 provides
sufficient
gain to drive
a monitoring
device
such as a chart
recorder
or other
readout.
The Model 427 in this
case provides
an output voltage
which
is calibrated
in volts
per ampere
a.3 in equation
10.
Eq. 10
Iin = - (V,,t I GAIN)
Example :
GAIN = 106 voltslampe~e
” O”t = +500 In”
The input
current
Iin would be:
lin
= - (5x10-~vo1ts/106vo1ts
per ampere)
Iin
= - 5 x 10-7 amperes
3-2.
Table
3-l
illusNOISE BANDWIDTH CONSIDERATIONS.
trates
the trade-off
between
fast
rise
time and dynamic
For this
application
dynamic
range
is defined
range.
a.s the ratio
of maximum peak-to-peak
current
to peakPeak-to-peak
current
noise
is
to-peak
current
noise.
taken
as 5-times
the rms current
noise.
The maximum
peak-to-peak
current
is 2-times
the maximum full
scale
current.
NOTE
When using
current
suppression
the current-suppression resistor
should
be considered
as an additional
current-noise
generator.
The values
given
in Table
3-l do not include
the contribution
of the suppression
resistor.
Therefore
the selected
suppression
resistor
Rs, should
be as large
as possible
to minimize
the contribution
to current
noise.
RMS’Noise
Current
(Typical)1
AMPERES
104
105
106
107
108
109
1010
1011
10-3
10-4
10-5
m-6
10-7
1 With
KEY :
x
*
0471
up to
=
=
of
RISE TIME
CURRENT
VIA
FIGURE
TABLE 3-l.
as a Function
,vL..I,.,“,.,
PULL SCALE
GAIN
FREOUENCY
IHI1
I
300
100
30
10
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
2do-13
5~0-14
4x10-14
104’
:
*
10-9
lo-1o
*
2x10-15
100 pP input
shunt
1x1:-14
4x10-15
*x1:-14
1x10-14
capacitance.
Filter
Bandwidth
is greater
larger
Rise Times are useful
They do not further
improve
exceeds
100 DF.
Noise
Gain
Plot
of
noise-improvement
and Rise-Time
contours.
Setting
SETTING
3
*
*
*
*
MO-12
2d0-13
2do-13
1x10-13
increases
11.
1
.3
.l
.03
.Ol
*
*
1x10-8
1x10-9
1x10-10
1.5x10-11
5x10-12
2~0-12
2do-12
x
1.2x10-8
1.2x10-9
1.2x10-10
2x10-11
1x10-11
5x10-12
x
x
4x10-8
4x10-9
4x10-10
1x10-10
4x10-11
x
x
x
1x10-7
1x10-B
1x10-9
x
x
x
x
x
lx&
2x10-l2
5do-13
~0-13
4x10-13
aa input
than current-amplifier
bandwidth.
for increased
filtering
of the
the instrument
noise
contribution
shunt
capacitance
increases.
signal
arid noise
inherent
except
when the input
in the source.
shunt capacitance
9
MODEL 427
ACCESSORIES
SECTION
The following
Keithley
4-l.
GENERAL.
be used with
the Model 427 eo provide
venience
and versatility.
accesaaries
additional
Model
4.
can
con-
1007
ACCESSORIES
OPERATING INSTRUCTIONS.
4-2.
Manual
is supplied
with
each
operating
information.
Rack Mounring
A separate
Instruction
accessory
giving
complete
hit
Description:
Application:
The Model 1007 is a dual rack mounting
kit with
overall
dimensions
3-l/2
in.
(64 mm) high and 19 in.
(483
The hardware
included
in this
kit
consists
mm) wide.
of two Angle Brackets,
one Mounting
Clamp, and extra
mounting
BCreWS.
The Model 1007 co""erts
any half-rack,
style
"M"
instrument
from bench mounting
to rack mounting
in
a standard
19-inch
rack.
The kit
may also be used
for rack mounting
19-inch
full
rack width
insfrultE"tS.
The Model 1007 Rack Mounting
Kit can be used to m"u"t
instruments
of 11 inch or 14 inch depth.
The user
should
decide
the position
af the i"~tr"me"ts
to be
rack mounted.
The Assembly
Inaeructions
refer
co
instruments
positioned
as shown and identified
as
instrument
“A” and "B".
10
Parts
List:
Item
NO.
DWCl+ltiO”
22
Angle
23
Screw,
Phillips
24
Mounting
VY
Keq'd
Bracket
16-32 x 5/8,
Pa" Hd
Clamp
%6-32
Pa"
x 1,
Hd
Keithley
Part No.
2
27410B
6
-_
1
247988
1
__
3
_-
25
Screw,
Phillips
26
Kep Nut
27
Screw,
Phillips
116-32 X l/2,
Pa" Hd
2
__
28
Screw,
Phillips
116-32 x 718,
Pa" Hd
1
__
116-32
0877
ACCESSORIES
MODEL 427
Model
Assembly
1007 Dual
MountinS
Kit
Instructions:
1.
Before
assembling
the rack kit,
determine
the
pasition
of each instrwnent.
Since the inserumenfs
can be mounted
in either
location,
their
position
should
be determined
by the user’s
meas”rement.
The
following
instructions
refer
to instruments
“n” and
UB” positio”ed
as shorvn.
For mounfinS
19-inch
full
rack Width instruments,
disregard
steps
2 through
5.
2.
Once the position
of each instrument
has been
determined,
ebe “side
dress”
panels
on both sides
of
each instrument
should
be removed.
Renxwal
is
accomplished
by looseninS
the screwy
(Item 8, oriSinal
hardware)
in two places.
Slide
the “side
dress”
panels
co the rear
of the instrument
to remove.
3.
The mountinS
clamp is installed
on instrument
“A” using
the oriSina1
hardware
(Item 8).
With the
screws
removed,
insert
the “mounting
clamp”
behind
the “corner
bracket”
(Item
7) and replace
the screws
to hold the mounting
clamp in place.
0777
Rack
4.
Tighten
the screwy
(Item
8) on instrument
Insert
the “mounting
clamp”
behind
the “corner
bracket”
(Item
7) an instrument
“8” a8 shown.
“B”.
5.
When mounting
instruments
having
the same depth,
a screw
(Item 25) and kep nut (Item 26) are required
to secure
the two instruments
together.
When ,,,ouneing instruments
of different
depth,
da not use kep
nut (Item 26) but substitute
shorter
screw
(Item 28).
6.
Attach
an “anSle
bracket”
(Item 22) on each
instrument
using hardware
(Item 23) in place
of the
original
hardware
(Item 8).
For 14 in.
long instruments use 116-32 x 518 Phillips
screw
(Item
23) with
116-32 kep “uf
(Item 26).
7.
The bottom
cover
feet
may be removed
if necessary.
and
tilt
bail
assemblies
8.
The original
hardware,
side dress
panels,
and tilt
bail
assemblies
should
be retained
for
ure conversion
back to bench mountine.
feet
fut-
11
CIRCUIT
DESCRIPTION
MODEL 427
SECTION
6.
CIRCUIT
DESCRIPTION
5-1.
GENERAL. The Made1 427 is composed of a feedbeck amplifier,
e X10 gain filter
section,
suppression
.“d
power supply
circuits
ee show” in Figure
12.
The
feedback
emplifier
is located
an the “Amplifier
Beerd”,
The filter
circuitry
is located
on the “Pilter
PC-289.
The power supply
circuitry
is
Board”,
PC-291,
PC-292.
located
on the “Mother
Board”,
PC-290.
a.
+15 ” Reguletor.
AC power ia tapped
from one
secondary
of transformer
T301.
The ec ia rectified
by
P full-weve
bridge
rectifier
(D301).
Trensistor
Q301
is the series
pees reguletor.
Integrated
circuit
QA
301 is . self-conteined
reference
end regulating
ciralit.
Potentiometer
R304 is a” internal
voltage
edjustment.
Resistor
R307 serves
as a current
limit
device.
FEEDBACK AMPLIFIER
(PC-289).
The feedback
empli5-2.
fier
is composed
of e high-gain
amplifier
connected
ee
The feedbeck
resietors
R22o through
e feedback
emmeter.
R227 are set by the GAIN Switch
(SZOl).
The high-gain
emplffier
is composed
of a dual FET input
stage
(Q20IA
end B), e differential
amplifier
(QAZOl),
end en output
The feedback
is connected
from
stage
(9203 end Q204).
resistor
R201 to the cutput
stage
et Q203 end Q204.
Potentiometers
R232, R233, and R234 ere internal
frequency compensetion
controls
for leg,
lOlo,
end 1011
Potentiometer
R235 is the ZBRO
gains
respectively.
The full
scale
output
of the feedback
AD., cantrol.
emplifier
is 1 volt.
b.
-15 ” Regulator.
AC power is tapped
from one
secondary
of trenaformer
T301.
The ec is rectified
by
P full-wave
bridge
rectifier
(D302).
Trensietee
Q302
is the series
pees reguletor.
Integrated
circuit
QA302 is e self-contained
reference
end regulating
circuit.
Potentiometer
R309 is en internal
voltage
ad,ustment.
Resistor
R307 mrves
as a current
limit
device.
CURRKNT SUPPRESSION CIRCUITRY
(PC-290).
The
5-5.
suppression
is applied
et the input
es show” in Figure
The N&X AMPERES Switch
(5303)
sets the current
15.
suppression
in decade
steps
from lo-3
te lo-lo
*Slp.3=.3*
(Resistors
R325 through
R332).
Potentiometer
R333 is
the FINE Control
which
provides
adjustment
frnn
0 to
1.5 times
the WAX setting.
Switch
S304 eete the polarity
(either
+ end - 15 volt
eource).
Current
suppresaionis
e function
of V,,&S,
--
The filter
circuit
ie composed
PILTBR (PC-292).
5-3.
of e high-gain
amplifier
connected
aa e 12 dB/octave
low pass filter
es sham
in Figure
13.
The amplifier
consists
of intel(rated
circuit
QAlOl end ~“tp”t
stege
Full
scale
output
ie 10 ;olts.
(QlOl
end Q102).The gain is established
et X10 by resistors
RllO end
Potentilnwtel:
RlOS is en internal
zero
R112 + R113.
Potentiometer
R113 is en interns1
gain
adjustment.
adjustment.
where
“cS
= Voltage
et
IQS = Series
Exemple:
If
The pewer supply
provides
POWER S"PPLY (E-290).
5-4.
+15 V dc et up to 70 mA for the amplifier
circuits.
The regulator
circuits
ere composed
of identicel
camponents
end are connected
ee shown in Figure
14.
end
the*
the
wiper
Resistor
of
(R325
R333.
through
R332).
MAX AMPEP.Rs = 10-b
if
“cS
Its
= cl5
= +15v
107n
”
= +1.5
x 10-G
amperes
RISE TIME
GAIN
III
r-5
I
I
FILTER
2!5
SUPPRESSION
FIGURE
12
12.
Block
die‘rr
of
l
hi‘h-‘peed
current
l mplifier
0471
Cl01
I,
r--------1
RIOI
0
RI16
FIGURE
0471
16.
component
Layout
- PC-291.
13
COMI
1
14
FIGURE 17.
Component Layout
- PC-290.
MODEL 427
COMPONENTLAYOUTS
?
FTGURE 18.
component Layout - PC-289.
0471
component
FIGURE 19.
Layout - PC-292.
15
MODEL 427
COMFUNENTL4YOoTS
PC-290
FIGURE
16
20.
Chaaais
- Top View.
0471
MODEL 427
SECTION
6.
REPLACEABLE
PARTS
turer's
Part Number,
and the Keithley
Part
Also included
is a Figure
Reference
Number
applicable.
The complete
name and address
Manufacturer
is listed
in the CODE-TO-NAME
following
the parts
list.
REPLACEABLE PARTS LIST:
This section
contains
6-l.
a list
of components
used in this
instr"ment
for user
The Replaceable
Parts
List
describes
the
reference.
individual
parts
giving
Circuit
Designation,
Description,
Suggested
Manufacturer
(Code Number),
Manufac-
Number
where
of each
Listing
TABLE 6-l.
Abbreviations
and Symbols
A
ampere
Cb"ar
cem
cefr*
Cer Trimmer
camp
Carbon Variable
ceramic
Disc
Ceramic
Tubular
ceramic
Trin!mer
Composition
DCb
twsig.
Deposited
Designation
EAL
ETB
ETT
Electrolytic,
Elecrrolytic,
Electrolytic,
F
Fig
farad
Figure
GCb
Glass
k
kilo
I-I
micro
M
Mfr.
MeF
MY
~~~ (106)
Manufacturer
Metal
Film
Mylar
NO.
Number
Aluminum
Tubular
Tantalum
HOW TO USE THE REPLACEABLE PARTS LIST.
This
6-3.
Parts
List
is arranged
such that
the individual
types
of components
are listed
in alphabetical
order.
Main
Chassis
parts
are listed
followed
by printed
circuit
boards
and other
subassemblies.
a.
NOW TO ORDER PARTS.
Replaceable
parts
may be ordered
through
Electrical
the
0471
iloard
Board (Power
Board
ohm
&
P0ly
pica
(10-12)
Printed
Circuit
Polystyrene
Ref.
Keference
TCU
Tinner
v
volt
w
w/l
WW"ar
watt
WiR?WO"nd
Wirewound
(103)
(10-6)
Sales
Service
Department,
or your nearest
Keithley
b.
When ordering
formation.
1.
2.
3.
4.
5.
parts,
Variable
Keithley
Instruments,
representative.
include
the
following
Inc.
in-
C,
All
parts
listed
are maintained
in Keithley
Spare Parts
Stock.
Any part
not listed
can be made
available
upon request.
Parts
identified
by the
Keitbley
Manufacturing
Code Number 80164 should
be
ordered
directly
from Keithley
Instruments,
Inc.
TABLE 6-2.
Schematics
and Diagrams
Schematic
Supply)
Copperweld
Instrument
Model Number
Instrument
Serial
Number
Part Description
Schematic
Circuit
Designation
Keirhley
Part Number
Description
Amplifier
Mother
Filter
Carbon
Carbon
6-2.
ELECTRICAL SCHEMATICS AND DIAGRAMS.
Schematics
and diagrams
are included
to describe
the electrical
circuits
as discussed
in Section
5.
Table
6-2 idencifies
all
schematic
part
numbers
included.
6-4.
enclosed
n
PC-289
PC-290
PC-291,
PC-292
I
247660
247680
247671)
17
REPLACEABLE
PARTS
MODEL 627
TABLE 6-3.
Designation
PC Board
100
100
200
300
300
300
series
20
20
21
23
23
23
PC-291
PC-292
PC-289
PC-290
PC-290
PC-290
Filter
Circuit
Filter
Circuit
Amplifier
Power Supply
SuppressFan
circuit
Overload
Circuit
I
TABLE 6-4.
Mechanical
Parts
Itern NO.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
1
16
17
18
19
20
\
Qty.
a Line
Power
Cord
WARNING
other
Per Assembly
Keithley
Part
No.
Figure
NC
21
Chassis
Assembly
Front
Panel Assembly
Front
Panel
Screw,
Slotted,
6-32 x 318
Front
Panel Overlay
Rear Panel
Side Exerusion
Left
Side Extrusion
Right
corner
Bracket
Screw,
Socket,
6-32 x 114
Screw,
Phillips,
6-32 x l/4
Clip
for Side Dress
Side Dress Panel
Tap Cover Assembly
Top CO"er
Screw,
Socket,
6-32 x 5116
Bottom
Cover Assembly
Bottom
cover
Screw,
Socket,
6-32 x 5/16
Feet Assembly
Feet
Ball
Tilt
Bail
Screw,
Phillips,
6-32
Kep Nut,
6-32
f,k
-\U'&
Using
Lise
247566
1
4
1
1
1
1
2
4
4
2
2
24758B
247608
24754C
24754C
247458
FA-101
24755B
24732C
1
4
24763B
2473X
1
4
243228
FE-6
171478
4
4
1
4
4
than
the
22
one
suppLied
with your instrument
may result
in an electrical
shock hazard.
If the Line Power cord is lost or
damaged, replace
only with
Keithley
Part No. CO-7.
18
0878
MODEL 427
REPLACEABLE PARTS
FIGURE 21.
FIGURE 22.
0471
Chassis
Assembly-Exploded
Bottom Cover Assemblv.
View.
REPLACEABLE
PARTS
HOOEL 427
("100"
FILTER BOARD
SERIES, PC-291*,
PC-292)
CAPACITORS
circuit
Ilesig.
Value
Cl01
Cl02
Cl03
Cl04
Cl05
150
680
.0022
6800
.022
oF
;i
p
pF
@
500
500
500
500
200
v
"
v
v
"
Cl06
Cl07
Cl08
c109*
c110*
.068
.22
.68
2.2
6.8
uF
'b
p
pP
@
100
200
200
200
200
Cl11
Cl12
68
330
pF
DF
c115*
Mfr.
Code
Mfr.
msig.
Keithley
Pat-e No.
Fig.
Ref.
P0ly
Poly
Poly
POlY
Poly
71590
71590
71590
71590
84171
CPR-15OJ
CPR-68OJ
CPR-22OOJ,
CPR-68OOJ
2PJ-223G
C138-15OP
C138-68OP
C138-.0022M
C138-68OOP
C108-.022M
19
19
19
19
19
"
v
v
v
v
MY
MY
MY
MY
MY
88480
13050
13050
13050
97419
~FR-683-1E
WA-.22j,F
SMlA-.68,,F
SMlA-2.2,,F
M2WF-6.LQF
C146-.068M
C47-.22M
C47-.68M
C47-2.m
C203-6.&I
19
19
19
16
16
.Ol
500
500
500
500
200
v
v
"
"
"
P0ly
Poly
Poly
Poly
Poly
71590
71590
71590
71590
84171
CPR-68J
CPR-330.1
CPR-1OOOJ
CPR-3300J
2PJ-10x
C138-68P
C138-33OP
C138-.OOlM
C138-.0033M
C108-.OlM
19
19
19
19
16
Cl16
Cl17
Cl18
c119s
c120*
.033
.l
.33
1
3.3
100
200
200
200
200
v
v
v
"
v
MY
MY
MY
MY
MY
88480
13050
13050
13050
13050
3FR-333-1E
SMlA-.lPF
SMlA-.33pF
SMlA-1pF
SMlA-3.3,~F
C146-.033M
C47-.lM
C47-.33M
C47-1M
C47-3.3M
19
19
19
16
16
Cl21
Cl22
Cl23
Cl24
5
5
33
100
CerIl
CerD
CerD
&lZIl
72982
72982
72982
72982
m-050
m-050
DD-330
m-101
C64-SF
C64-5P
C64-33P
C64-1OOP
19
19
19
19
Mfr.
code
Mfr.
Lhsig.
Keithley
Part No.
Fig.
Ref.
22526
12040
01295
01295
04713
04713
80164
20052
LM301AN
lN914
lN914
2N3903
2N3905
SW33S
CS-237
IC-24
RF-28
RF-28
TG-49
TG-53
02660
31-2221
CAP-18
19
19
19
19
19
19
19
3
Rating
-
\
1000 "
1000 "
1000 "
100 "
MISCELLANEOUS
CiX”it
”“C3l.g.
no1
QAlOl
0101
0102
QlOl
Q102
SlOl
5102
_-
Type
connector,
lo-Pin,
Mini-w
Integrated
Circuit
Diode,
Rectifier
Diode,
Rectifier
Transistor
Transistor
Switch,
Rotary,
RISE TIME
Connector,
BNC, UG1094A/U
Cap, BNC, mates with
5102
;;r;g
RESISTORS
Value
RlOl
R102
R103
RlO4
R105
20
7.78
8.41
51.7
51.7
10
Rating
kn
kn
kn
kR
kn
I%,
l%,
l%,
1%,
l%,
l/8
l/8
l/8
l/8
l/8
w
W
w
w
w
Type
Mfr.
Code
Mfr.
Desig.
Keiehley
Part No.
Fig.
Ref.
MfF
MtF
MtF
MCF
MtF
07716
07716
07716
07716
07716
CEA-7.78KG
CEA-8.41~Jl
cm-51.7m
CEA-51.7UJ
CEA-lO*
R88-7.78k
R88-8.41k
R88-51.7k
R88-51.7k
R88-10k
19
19
19
19
19
1072
FlLTER BOARD (cont'd)
RESISTOR8 (cont'd)
R106
RIO,
R108
R109
RllO
Mfr.,
Code
Mfr.
Desig.
Keithley
i'art
NO.
Fig.
Ref.
w
w
w
w
w
MtF
MCF
Camp
MCF
MtF
07716
07716
80294
91637
91637
CF.&-lkn
CEA-lkS2
3009P-200
Km-Ml
MFF-536R
R88-lk
R88-lk
RP-89-200
R169-1M
R168-536k
19
19
19
19
19
10%. l/4
.l%,
l/E
.75
l%, l/8
10%, l/4
w
w
w
W
w
camp
MCF
camp
MtF
camp
44655
91637
80294
07716
44655
RCO7-102
MFF-61.9kR
3009P-2k
CPA-l.Okn
KC07-471
R76-lk
R168-61.9k
K-89-211
R88-10k
,176.470
19
19
19
19
19
1%,
1%.
lo%,
l%,
l%,
w
w
W
W
W
MU
MU
camp
MtF
Ml3
07716
07716
44655
07716
07716
CEA-1.RkR
CEA-IOkR
RC07-471
CEA-200n
CEA-1Okn
R88-L.8k
R88-1Ok
R76-470
R88-200
R88-IOk
19
19
19
19
19
RCltF"g
1
kfl
1
kil
200
n
l%, l/8
1%, 1/B
75
:l%,
l/2
.l%,
112
61.9 kS
2
kn
10 kn
470
!?
1.8 kfl
10 k0
470
R
200
iz
10
kR
Rlll
RI20
Type
Value
l/8
l/8
l/8
l/8
l/8
‘WPLIFIER
BOARD
("200"
SERIES, E-289)
CAPACITORS
C203
C204
C205
C206
C207
C208
C209
c210
* C216
*C217
*C218
C219
c220 cG-5
c221
c222
C223
C224
**Nominal
1075
Value,
S201.
)
Mfr.
Mfr.
Keithley
Pig.
v
"
V
"
v
CerD
&l-D
&t-T
cem
MY
72982
72982
71590
72982
13050
loss-D22
801000X5F0102~
TCZ-1R5
801000~5~0102~
SM2‘+.047IJF
C22-.0022M
C64-.OOlM
c77-1.5P
C64-.ool~
C143-.047M
18
18
18
18
18
MY
CerD
13050
72982
SMZA-.047PF
00471
loss-"22
801000X5F0102K
TSDl-20-low
C143-.047M
C64-47OP
C22-.0022M
C64-.OOlM
C179-10M
18
18
18
18
18
801000X5F0102K
TSDI-20-10°F
8omoox5Foio2K
loss-D47
C64-.OOlM
C179-LOM
C64-.OOlM
C66-.0047M**
C22-.0047M
18
18
18
20
20
TCZ-IRS
3FR333-1E
801000X5F0102~
1oss-033
loss-D33
wp
c a-~w-r~s,fy
C146-.003M
18
C64-.OOlM
18
C22-.0033M
18
C22-.0033M
18
p
pF
UF
b
ilF
200
1000
1000
1000
20
"
v
v
”
"
”
v
v
72982
17554
,001
LP
10
.OOl
iJ.F
UF
1000
20
1000
.oo47
.0047
ilF*"
IiF
200
v
1.000 v
72982
17554
72982
97419
56289
470
47
5
1.5
1.5
,033
.OOl
.0033
.0033
pF
pF
PF
DF
6F
pF
UF
!,F
5
500
500
200
600
600
100
1000
1000
1000
71590
71590
00686
71590
71590
88480
72982
56289
56289
in
on Switch
1000
1000
600
1000
200
.047
470
.0022
,001
10
Selected
( * Located
Factory
"
v
v
v
"
"
"
”
v
Test
21
MODEL 427
FiXPLACEABLE PARTS
AMPLIFIER
CirCUit
Desig.
D201
0202
D203
D204
D205
D206
D207
D208
D209
D2lO
Type
Special
Special
Silicon,
Silicon,
NPN, case
NPN, case
TO-106
TO-106
SilkOn
Silicon
SiliCOtl
Silicon
BOARD (cont'd)
DIODES
Mfr.
Code
Mfr.
msiu.
Keithley
Part NO.
80164
80164
07263
07263
01295
.?&5sk
2133565
2N3565
lN645
01295
01295
01295
01295
01295
lN645
lN914
lN914
lN914
lN914
RF-14
RF-28
RF-28
RF-28
RF-28
18
18
18
18
18
Mfr.
Code
Mfr.
tlesig.
Keithley
Pare NO.
Fig.
Ref.
07263
80164
@715C
SW-337
IC-26
Jk: ;::c;,d
SW-337
?
,~>
02660
31-2221
cs-249
18
18
18
18
-2245&A
Z2&55A
TG-39
TG-39
RF-14
Fig.
Ref.
.2&l\;'
(*‘4 18
;> fj 3 :I ,~ c:Jj 1 S
18
18
18
MISCELLANEOUS
Type
QA201
s201
5201
5202
wegrated
Circuit,
Operational
Switch,
Rotary,
GAIN
Not Used
Receptacle,
BNC (UG1094AfU)
Amplifier
RESISTORS
( * Located
on Switch
5201.
)
Mfr.
Code
Mfr.
Desig.
Keitbley
Part No.
Fig.
Ref.
RC07
EB-lM
CBA-lOOki?
CF,A-23.2kn
CEA-22.lkn
R76-10
RI-1M
R88-100k
R88-23.2k
R88-22.lk
18
18
18
18
18
18
18
18
R201
R202
R203
R204
R205
10
1
100
23.2
22.1
n
MCI
kR
k0
k0
lo%, l/4
lo%, l/2
I%, l/8
l%, l/8
ix,
118
w
w
W
W
w
corn;
MtF
MW
MtF
44655
01121
07716
07716
07716
R206
R207
R208
R209
R210
10
18.2
10
12.1
499
ki?
kn
kfi
kO
n
l%,
l%,
l%,
l%,
l%,
118
l/2
l/S
l/8
l/S
W
w
w
W
w
MM
MtF
MtF
MtF
MtF
07716
07716
07716
07716
07716
CEA-1OM
CEC-18.2kQ
CEA-lOkS1
CBA-12.lka
CEA-4990
R88-10k
R94-18.2k
R88-10k
R88-12.lk
RS8-+,9-
R211
R212
8213
R214
R215
499
10
470
10
470
n
R
n
kn
n
l%, l/8
l%, l/S
lO%, l/4
l%, l/S
IO%, l/4
W
w
w
w
w
MtF
MtF
07716
07716
44655
07716
44655
CEA-499n
CEA-lOS2
RC07-471
CEA-low2
RC07-471
R88-449
RSS-10
R76-470
RSS-10k
R76-470
R216
R217
* R218
* R219
*R220
10
10
270
100
900
n
D
kn
n
a
10%. l/4
lO%, l/4
lO%, l/2
l%, l/2
l%, l/2
w
w
w
w
w
COmp
Camp
camp
Mm
DCb
'44655
44655
01121
07716
91637
RC07-100
RC07-100
EB-270kR
CEC-loon
DCF-l/2-90Ofi
R76-10
R76-10
Rl-270k
R94-100
812-900
18
18
20
20
20
* R221
"R222
9~R223
R224
R225
10
100
1
10
108
kn
kR
wl
MS?
n
l%, l/2
l%, l/2
l%, l/2
1%,1
1%,2
w
w
w
w
w
MtF
MtF
Mm
DCb
DCb
CEC-1OM
CEC-100kn
CEC-lMn
DC-l-lOM0
DC-2-1oSn
R94-10k
R94-100k
20
26
22
07716
07716
07716
91637
91637
3-01Lc
301&
:i
18
18
18
18
18
1072'
MODEL 427
REPLACEABLE
PARTS
AMPLIFIER BOARD (cont'd)
RESISTORS (cont'd)
Value
R226
R227
R228
R229
R230
R231
R232
R233
R234
R235
h~ominal
109
1010
*15
10
220
330
100
1
1
500
value,
n
n
R
kn
kn
kfi
kR
Mn
MCI
n
selected
Rating
Type
Mfr.
Code
mr*
Llesig.
:
10%. l/4"
10%. 114 w
lo%, l/4 w
GCb
GCb
camp
ComJ
corn;
63060
63060
44655
44655
44655
lo%,
camp
44655
80294
80294
80294
llelipot
l/4
w
l/2
112
,,,,,,,,m;,,.
112
in
E
Keiehley
Part NO.
Fig.
Ref.
g::::;10
x07-150
RC07-103
RC07-224
RZO-109
R*l-rb20
R20-10lC$3~5-,&0
R76-15
R76-10k
X76-220k
18
18
18
RC07-334
3068P-100k
3068P-Df
3068%1M
77PF.500
R76-330k
RP89-10Ok
RP89-lM
RP89-1M
RP-64-500
18
18
18
18
Mfr.
Code
Mfr.
Lksig.
Keithley
Part No.
Fig.
Ref.
80164
04713
04713
04713
2N5452
2N50892N3903
2N3905
25099.4"
'X-62
w-49
z-53
18
18
18
18
Fig.
Ref.
9
test.
TRANSISTORS
circuit
iksig.
Q201
Q202
Q203
Q204
*Selected
Type
Dual,
PET, case TO-71
Silicon.
NPN, Case TO-92
Silicon,
NPN, Case TO-92
PNP. Case TO-92
X-70
MOTHER BOARD PARTS LIST
("300"
SERIES, PC-290)
CAPACITORS
Type
Mfr.
Code
Mfr.
i%sig.
Keiehley
Part NO.
"
v
"
v
”
EAL
EAL
ETT
ETT
CC?!2D
90201
90201
17554
17554
72982
MT”-200m
MT”-ZOO!JF
TSD1-20-10pF
TSDI-zo-IO&IF
m-222
C177-ZOOM
C177-200M
C179-10M
C179-10M
C64-2200P
35
35
20
1000
20
"
"
"
"
"
EAL
EAL
ETT
CerD
ETT
90201
90201
17554
72982
17554
MTV-200UF
MT"-200!JF
TSDl-zo-10UF
DD-222
TSD~-20-10uF
C177-200M
C177-200M
C179-10M
C64-2200~
C179-10M
35
20
20
20
500
"
"
"
"
"
EAL
ETT
90201
17554
MTV-200m
TSDl-ZO-10pF
Tml-20-.47UF
TSDl-20-lO!JF
871-25u0-103M
C177-200M
C179-10M
C179-.47M
C179-10M
C22-.OlM
::
Keithley
Fig.
Value
Rating
c301
C302
c303
c304
c305
200 p
200 fl
10 llF
10 @
2200pF
35
35
20
20
1000
C306
c307
C308
c309
c310
200 p
200 UF
C311
C312
c313
c314
c315
10 GF
2200PF
10
fl
200 p
10 UF
.47 pE
10 P
O.Ol!JF
Mfr.
D301
D302
D303
0304
Four Wade
Four Diode
Silicon
Not Used
0305
Silicon
Bridge
Bridge
17
17
17
17
17
17
83701
83701
01295
__
m-10
PD-10
lN645
__
RF-36
RF-36
RF-14
__
17
17
17
--
01295
lN914
RF-28
17
REPLACEABLE
PARTS
MODEL 427
MOTHER BOARD (cont'd)
DIODES (cont'd)
Cit-CUit
rlesig.
D308
0309
D310
0311
0312
Mfr.
Code
Type
01295
01295
01295
01295
01295
MISCELLANEOUS
Silicon
SiliCOll
Silicon
Silicon
Silicon
Mfr.
Code
Type
CirCUFt
Llesig.
22526
Connector,
Mini-P"
22526
connector,
Mini-P"
Integrated
Circuit,
Voltage
Regulator
07263
Integrated
Circuit,
Voltage
Regulator
07263
07263
Integrated
Circuit
80164
Switch,
Line Voltage
80164
Switch,
"PUSH ON" Power with
lamp
Switch,
CURRENT SUPPRESS
80164
02735
Transistor
02735
Transiseor
04713
Silicon,
NPN, TO-92 case
Transistor,
80164
Switch,
POLARITY
75915
Fuse,
117",
.25A, Slo-Blo,
3 AG
71400
Fuse,
234",
1/8A,
Slo-Ho,
3 AG
80164
Transformer
82389
Receptacle,
AC
Line cord,
mates with
P305
70903
08806
Pilot
lamp, neon (replacement
far 5302)
07294
Pilot
Lamp, O"~RLOAD
iESISTORS
(*Located
on Switch
Mfr.
Value
Code
Rating
Type
R301
R302
R303
R304
R305
634
8.2
1.37
200
1.24
0
a
kfi
0.
kfi
l%, l/8
5%, l/2
1%, l/8
0.5
ix, ua w
MtF
R306
R307
R308
R309
R310
634
8.2
1.37
200
1.24
R
n
kn
a
k.Q
1%.
5%,
l%,
0.5
l%,
l/8
l/2
l/8
MtF
COtlIp
MtF
l/8
W:
w
w
W
w
R311
R312
R313
R314
R315
9.09
14
1
10
1
kfl
kn
kR
n
kfl
l%,
l%,
l/8
l/S
w
W
I%, ifa w
R316
R317
R318
R319
R320
9.09
1
1
14
10
kR
kfl
kR
kn
R
l%,
l%,
l%,
l%,
lO%,
R321
R322
R323
R324
hR325
10
10
330
47
10
kn
kfi
R
kfl
kn
5301
5307.
QA301
QA302
QA303
5301
S302
5303
Q301
4302
Q303
5304
F301
F301
T301
P305
__
DS-301
DS-302
24
w
w
w
w
lO%, l/4 w
l%, l/8 w
l/8
l/8
l/8
l/8
l/4
"
w
w
W
"
Mfr.
rJesig.
Ketthley
Part No.
Fig.
Ref.
lN914
lN914
lN914
lN645
lN914
RF-28
RF-28
RF-28
RF-14
RF-28
17
17
17
17
__
Mfr.
Desig.
Keiehley
Part NO.
Fig.
Ref.
47439
47439
UGA7723393
LEA7723393
A749C
SW-318
PBL-5-BSA3C7A
SW-339
40312
40312
2N3903
SW-236
313.250
MDL
TR-138
AC3G
17258-S
C/A(N&2P)
CF03ACS1869
S303.)
Mfr.
LkSiE.
CS-236
CS-236
IC-25
IC-25
x-27
SW-318
SW-340
SW-339
TG-54
w-54
TG-49
SW-236
F"-17
F"-20
TR-138
CS-235
co-7
PL-58
PL-51
17
17
17
17
17
3
3
‘20
17
17
17
3
3
3
20
3
-_
2
Keithley
Pat-t NO.
FFg.
Ref.
07716
01121
07716
80294
07716
CEA-634n
EB-8.2sl
CEA-1.37kn
3329P-200
CEA-l.lkO
R88-634
R19-8.2
R88-1.37k
RP-88-200
Rae-l.24
17
17
17
17
17
MtF
07716
01121
07716
80294
07716
CEA-634n
m-8.2$?
CEA-1.37kR
3329P-200
CEA-l.lkR
R88-634
R19-8.2
R88-1.371
RP-98-200
~88-1.24
17
17
17
17
17
MtF
MtF
MtF
CO*p
MtF
07716
07716
07716
44655
07716
CEA-9.09kn
CEA-14kfi
CERlkR
RC07-100
CEA-lkn
R88-9.09k
R88-14k
R88-lk
R76-10
R88-lk
17
17
17
I 17
17
MCF
MtF
MtF
MtF
07716
07716
07716
07716
44655
CEA-9.09kn
CFA-1kR
CBA-1kR
CEA-14kn
a07-100
,R88-9.09k
RBB-lk
R88-lk
R88-14k
R76-10
17
17
17
17
17
44655
44655
44655
44655
07716
RC07-103
RC07-103
x07-331
x07-473
CEC -1Okfl
R76-10k
R76-10k
R76-330
R76-47k
R94-1Ok
COmp
MtF
17
17
17
1Y
20
0574
MODEL 427
REPUCEABLE
PARTS
MOTHER BOARD (cont'd)
RESISTORS (cont'd)
circuit
lksig.
Value
Rating
100 kn
1
10
100
109
hR331
*R332
F.333
R334
R335
1176
Mn
Mn
MO
n
1010
R
1011
il
10
k0
33
kn
68
kSI
Type
l%, l/2
l%, l/2
l%, 1
1%,2
2
lO%,
lO%,
l/2
l/4
"
w
w
w
W
w
w
Mfr.
Code
MtF
MtF
DCb
DCb
GCb
CCb
GCb
ww
Camp
C0mp
63060
63060
12697
01121
44655
Mfr.
Desig.
Keithley
Part No.
Fig.
Ref.
CEOlOOI&
CEOM-i
DC-l-1OMn
DC-2-100Mo
Rx-l-1090
R94-look
R94-1M
20
Rx-l-101On
Rx-l-1olln
62JA-10kiI
EB-33kn
RC07-683
-to
.rw-dl
RP-YZ-10k
Rl- 33k
R76-6Sk
f$e~-/“G
2.
pw3~-@620
17
17
__
25
MODEL 427
SECTION
7.
CALIBRATION
This section
contains
procedurea
for
GENERAI..
7-1.
checking
the instrument
to verify
operation
within
specifications.
The procedures
and adjustments
should
be performed
in the exact
sequence
given
to obtain
satisfactory
results.
2.
a.
Preliminary
1.
Power
427 line
cord
in
Set the 117-234
a).
volt
position
and plug
234 volt
line.
left
volt
the
switch
42, line
a "ariac
to the 234
cord into
the
b).
Check the 215 volt
supplies.
read i15 volts
?1O mV with
less
than
to-peak
ripple.
Calibration.
4.
Supplies.
Overload
Circuit
a) f Connect
Set the Model
Connect
Model 163 between
the +15 volt
test
a).
point
and chassis
and adjust
the f15 volt
potentiometer
R309 for +15 Volts
t10 "".
"Sing
the
oscilloscope
check for less
than 1 m" peak-topeak ripple.
b).
Connect
Model 163 between
the
point
and chassis
and adjust
the -15
tiometer
R304 for -15 volts
?lO mV.
than 1 mV peak-to-peak
ripple.
to
Check the il5
volt
supplies
with
the "ariac
b).
adjusted
for 90 and 125 volts.
The voltages
should
be i-15V +20 m" with
less
than 1 mV peak-to-peak
ripple.
3.
234 Volt
Operation.
PKOCED”RES .
7-3.
Regulation.
Plug the Model
a).
with
Line Monitor.
Use the test
equipment
specified
7-2.
TEST EQUIPMENT.
Equivalent
instruments
may be substiin Table
7-1.
tuced provided
the accuracy
tolerances
are equal
to or
better
than the equipment
specified.
NOTE
The Suppression
Max. Amperes switch
will
be
in the E
posirion
unless
stated
otherwise.
Line
b).
Set
the
Check.
Model
163 to
163 to the
the 10 volt
Model
427 controls
GAlN :
SUPPRESSION:
RlSE TIME:
-15 volt
test
volt
potenCheck for less
They should
1 mV peak-
Model 427 output.
range.
as fallows:
106 "olts/amperes
(-1 10-5 amperes
300 Ins
c).
Turn the Suppression
Fine control
a reading
of approximately
t9.5
V on the
163.
The Model 427 overload
light
should
to obtain
Model
be off.
TABLE 7-l.
Test Equipment
I-
1nStr”ment Type
Picoampere
Digital
10-14
il
to
uv to
Mfr.
1.1
x lo-4A
lOOOV,
Oscilloscope
__
Function
-_
Generator
Microvolt-*meter
10 "V fO lOOOV,
Variable
90-140V
rms,
90-140V
rms,
Line
True
26
source
Voltmeter
Specification
Transformer
Voltage
RMS "TVM
Monitor
Keithley,
0.1%
of
reading
Model
-11
Hz
X-60
Hz
to
10-l*
261
Model
Keithleiy,
variac
163
Mod'+,~~
Wavetek,
10
No.
Keithley,,,~Model
Tektronix,
50-60
_-
and Model
or
111 or
Model
5618
,,~
130
l?i
-I
',l_
~/,'
-Ballantine,
Model
320
1072
MODEL 427
CALIBRATION
d).
Slovly
CW until
the
should
occur
e).
switch
on the
5.
t”rn
the Suppression
Fine control
overload
light
comes on.
~,,is
between
+10 and +11 volts.
10” amperes and adjust
the front
mnel
pot R333 for
connect
DVM (1OV range)
CO
a reading
of l.OOOV.
output
of 427 and adjust
Filter
Amplifier
gain
pot (R113)
for a reading
of 10.00 volts.
Set the Model 427 Suppression
Polarity
ta (+) and repeat
steps & and c,
Readings
DVM will
now be negative.
current
a).
Set
suppression
Amplifier
Set the Model 261 to N6
ampere
and the
a).
Model 427 gain to 10’ V/A and connect
the test
set up as shown in Figure
23 using a BNC TEE
connector
on the Model 427 input.
Zero.
the Model 427 gain switch
to E
and Rise Time to
to zero
30” ms.
check,
b).
With no input
connected
set up, the Model
153 for CENTER ZERO and VOLT K-21%. Zero on the
100 pV range then set the range to 1. mV.
b).
Turn the 427 front
panel zero control
ccw
until
overload
light
comes an.
Then very slowly
turn
the zero control
cw until
light
goes off.
C”“ti”“e
turning
c0*tr01
cw until
light
comes on
again.
Then slowly
turn control
ccw and set in
region
where overload
light
stays
off.
6.
Filter
Amplifier
Zero
c). >ir&t$
Model 261 output
OFF increase
the -1
153 $ensftivity
to 300 v” range while
mai”camCig~
a “0” Indication
on the Model 153
using
the Model 427 front
panel zero control.
Correct
drift
with
the Model 427 zero co”trol
as
needed during
checks.
and Gain.
a).
Set the Model 427 gain to lo4 V/A and Rise
Time to 300 me.
Connect
the Model 163 DW to the
Model 427 output.
Set the Filter
Amplifier
zero
pot (F.108) for 0 ilm”
at the Model 427 output.
d).
Switch
the Model 261 between
,..~as\p,eeded
to obtain
a steady
reading
! 153.’
me reading
should
be leSS tha
OFF and (+)
on the Model
300 pv.,
Pe).
Repeat step $ but witch
befw:&,FF~%“d
(-) on tiy Model 261.
The reading
should
be
less thqh +300 u”.
Re-zero
the Model 427.
Set the 427 Gain to lo5 V/A and cmmect
a
b).
DVM (1V range)
to the OUtPUt Of the first
stage amplifier
(QA201, Q203, 4204) at location
on PC-290
(mother
baard)
at jumper
found directly
below potset the Suppression
to
entiometers
R232 and R233.
FIGURE 23.
0877
Measurement
of
Input
Voltage
Drop.
27
CALIBRATION
MODEL 427
TABLE 7-2.
427
GAIN V/A
427
RISE TINE
11
;;10
1.0
.3
.l
.03
.03
.Ol
.Ol
.Ol
109
108
107
106
105
104
8.
Amplifier
Rise
WAVETEK
FREQUENCY
ms
me
ma
ma
me
m
me
r@E
100
500
1
2
10
10
10
10
RISE TIME
ADJUSTMENT
MAX 10-90x
RISE TIME
Hz
Hz
kHz
kHz
kHz
kliz
kH*
kliz
1.50
0.40
0.22
0.60
0.40
0.015
0.015
0.015
Time.
9.
Connect
Function
Generator
to the Model
a).
427 input
and connect
the Model 427 rear panel
output
t" the Oscilloscope
Using
the test
set up
shar"
in Figure
24.
"Is
m
la8
me
me
Ins
ms
ms
Amplifier
Slider
Slider
Pot
None
NO"=
NO"=
Ncme
NO"=
6 Pot
6 pot
Noise.
a) . Connect
427 input
high
B 1OOpF capacitor
end ground.
between
Model
Connect
the TRMS VTVM to the Model 427
b).
rear panel
output
and check the Model 427 BMS
output
noise
for all
settings
in Table
7~3.
10.
Adjust
the 10' through
1011 ranges
within
b).
the specified
10% to 90% rise
time using
the triangular
wave frequency
and adjustment
listed
in
the table.
Adlust
the Function
Generator
as
needed to obtain
a 10 volt
peak-to-peak
output
Check the 10 through
lOti
from the Model 427.
rangea
for the specified
rise
times.
There should
be no overshoot
on any of the ranges.
Filter
Set
4.
Rise
the
Time.
oscilloscope
VERTICAL INPUT:
COUPLING:
TRIGGER:
COGPLING:
controls
as follows:
ZV/Di".
DC'
Ext.
AC
Shielded
/
-
,I,,,1
,r CAPA
PUNCTION
GENERATOR
-
_
I
L--
I
J
FIGURE 24.
,
Measurement
of
I
Rise
I
Time,
TABLE 7-3.
GAIN V/A
(427)
11
;;10
i
28
109
1oS
107
106
105
104
RISE TIME
(427)
1.0
.3
.l
.03
.03
.Ol
.Ol
.Ol
ms
In*
ms
me
me
ma
ma
m
TRUE
MS
T
100
30
10
10
3
3
3
3
"I"
mv
mv
mv
mv
mv
mv
rev
MAX. RMS
NOISE
40
20
10
5
2
2
2
2
mv
mv
mv
mv
nlv
mv
mv
mv
0574
>
MODEL 427
CALIBRATION
TABLE 7-4.
427 Rise
setting
Wavetek
Frequency
10
10
.l
.l
1
1
10
1.0
10 kHz
1 kHz
1 kHz
100 HZ
100 Hz
10 H7.
10 "7.
10 HZ
!a
pa
Ins
nla
ms
me
me
tn.5
FUNCTION
GENERATOR
.Ol
.03
.l
.3
1
3
10
30
SERIES
RESISTOR
25.
Ins
me
In*
me
me
Ins
Ills
Ilie
Measurement
of
b). Set the Model 427 gain to lo4 V/A. "sing
the series
resistor
(104) and the square
wave frequency listed,
check the filter
amplifier
lo-90%
Set the Function
Generator
amplitude
rise
time.
as needed to obtain
a 10 volt
peak-to-peak
""tput
The overshoot
and dipping
or
from the Model 427.
a combination
of both should
not exceed t 10%.
Trigger
the Oscilloscope
from the Function
Generator
sync output.
Filter
Rise
Max lo-90%
RfSe Time
.015
.040
.15
.37
1.1
3.7
11
37
MODEL 427
CURRENT
AMPLIFIER
1om
FIGURE
Time
In*
me
ms
ma
Ins
Ins
m
me
OSCILLOSCOPE
Time.
for
.2V/Div
and set
c) . Set the Oscilloscope
the Function
Generator
for 1 volt
out of the
"sing
the square
wave frequency
listed
Model 427.
below check the lo%-90% rise
time of the filter
amplifier.
“*“etek
TABLE 7-5.
OSCillO*COpe
L
0574
.l
.l
eec
set
Frequency
1 HZ
1 HZ
427 Rise Time
Setting
Max lo-90%
Rise Time
100 me
300 tns
110 Ins
370 Ills
29
CALIBRATION
b.
Final
1.
MODEL 427
Calibration.
4.
Accuracy.
through
on the
Gain
Step the Suppression
and Cain switches
the positions
in Table
7-7.
The readings
Model 163 should
be within
the tolerance
Connect
the Model 261 Picoampere
Source
to
4.
the input
of the Model 427 and connect
the Model
163 to the Model 427 output.
Set the Model 427
Tima Co"sta"t
to 300 Ins.
TABLE 7-7.
SUPPRESSION
Set the Model 163 on the 1 volt
range and
b).
step the Model 261 and Model 427 through
the ranges
The DVM readings
must be within
the
in Table
7-6.
For positive
current
inputs
the voltrange given.
age OUtpUt is negative.
LO-lo
10-9
10-8
lo-7
lo-6
10-z
TABLE 7-6.
427 Gain
-261
IO-3
10
Model
.98V
.98V
.98V
.98V
.98V
.98V
.96V
.96V
2.
Offset
to
to
to
to
to
to
to
to
1.02V
1.02v
1.02v
1.02V
1.02V
1.02V
1.04V
1.04V
current
b).
Connect
the Model 163 to the Model 427 output and set it to the 1 volt
range.
The reading
on the Model 163 should
be less
than 100 mV.
30
current
-lov
-lOV
-lOV
-10"
-lOV
-lOV
-lOV
-lov
t10
-i600
i-600
i600
t600
f600
C600
i-3
mv
mV
mV
mV
mV
mV
mV
"
163
Re-check
the current
amplifier
and filter
a).
amplifier
zero.
Place
a CAP-18 on the Model 427
input
and sat the Model 427 Cain to 1011 V/A and
Rise Tim2 to 300 ma.
3.
MODEL 163
suppression.
Repeat stepa a and c with
the
d)
polarity
switch
in the (-) position.
163 readings
will
now be positive.
4.
suppression
The Model
Drift.
4.
Set
the
Model
GAIN:
SUPPRESSION:
RISE TINE:
POLARITY:
427 controls
as follows:
LO5 V/A
1O-7 ampere
1 ms
(+) or c-j*
*POLARITY is (+) for setting
recorder
printer
left
of zero and (-) for setting
printer
right
of zero.
a).
Place
a CAP-18 an the Model 427 input
and
set the gain to lo11 V/A.
Connect
Model 163 to
the Model 427 output
and set it to the 10 volt
range.
Set the recorder
sensitivity
to 10 mV full
b).
scale
and "sing
the suppression
FINE control
set
the recorder
printer
to a convenient
spot for
recording
drift
of the Model 427.
Set the
lo- b/6 , set the
tral
to obtain
Model 163.
a 1 hour warm-up
the Model 427
c) . After
should
drift
no more than t500 u" (five
minor
divisions)
in any subsequent
24 h&r
period
*500 lJV/"C.
Model 427 Suppression
switch
to
Polarity
to (+) and the Fine co"a -10 volt
i10 m" reading
on the
0574
-
I’
/ ’
:
0
ip
A
IT-----3-----J
I
I
Y
SERVICE
Model
FORM
No.
Serial
No.
P-0. No.
Name
Date
Phone
Company
Address
City
State
Zip
List all control settings and describe problem.
(Attach additional
Show a block diagram of your measurement system including
is turned on or not). Also describe signal source.
Where is the measurement
being performed?
(factory,
controlled
Any additional
Ambient
(whether
out-of-doors,
etc.)
power
(If special modifications
OF.
Temperature?
Other?
OF. Rel. Humidity?
information.
laboratory,
connected
Variation?
What power line voltage is used?
Frequency?
Variation?
all instruments
sheets as necessary.)
have been made by the user, please describe below.)
*Be sure to include your name and phone number on this service form.
Addendum
29103-C-l
u/a/a3
Instruction Manual Addendum
Model 427 Current Amplifier
The following change information is provided as a supplement to thk manual in order to provide the
user with the latest improvements and changes to the manual in the least amount of time. It is recommended that this information be incorporated into the appropriate places in the manual immediately.
Replace the information contained in step 8, page 28, under Amplifier Rise Time, with the following
procedure:
8. Amplifier Rise Time
a. Connect the Function Generator to the Model 427 input and connect the Modal 427 rear panel
output to the oscilloscope using the test setup shown in Figure 24.
b. Adjust the 109 through 101’ rangas within the specified lo%-90%
rise time using the triangular
wave frequency and adjustment listed in Table 7-2. Adjust the Function Generator, as needed, to
obtain a 10 Volt p-p output from the Model 427.
c. Without altering the test sat-up, verify that the 10 through to8 ranges meet the rise time
specifications in Table 7-2. Adjust the Function Generator, as required to obtain a 10 Volt p-p output from the Modal 427. There should be no overshoot on any range.
d. Remove the 1OOpFcapacitor from the test set-up and connect the Function Generator directly to
the Modal 427 input. Verify the 101through 106 10% -90% rise time, using the square wave fraquency. per Table 7-2. There should be no overshoot on any range except for the 104 V/A which
should be lass than 10% overshoot.
.
.
m
INSTRUMENTS
Model 427 Current Amplifier Addendum
INTRODUCTION
This addendum to the Model 427 Current Amplifier Instruction Manual is being provided in order to supply
you with the latest information in the least possible time. Please incorporate this information into the manual
immediately.
Page 3; Note that in Figure 2 the dials on the knobs are now black.
29103-c-2
/7-90
Page 20; Replace Table with the following:
FILTER BOARD
(“100” SERIES, PC-291’,
PC-292)
CAPACITORS
clrcult
Deslg.
Value
Rating
Type
Cl01
Cl 02
Cl 03
Cl04
Cl05
Cl06
Cl07
Cl06
C109’
c110*
Cl11
Cl12
Cl13
Cl14
Cl 15’
Cl16
Cl17
Cl16
Cl19’
Cl20
Cl21
Cl 22
Cl23
Cl24
15OpF
68OPF
.0022pF
68OOpF
.022pF
.066pF
.22kF
.66PF
2.2kF
6.6pF
66PF
33OpF
.OOlpF
.0033pF
.OQF
.033pF
.lj~F
.33yF
1P
3.3pF
5pF
5pF
33pF
1OOpF
5oov
5oov
5oov
5oov
2oov
1oov
2oov
2oov
2oov
2oov
5oov
5oov
5oov
5oov
2oov
1oov
2oov
2oov
2oov
2oov
1ooov
1ooov
1oov
1 oov
P0ly
Poly
Poly
Poly
Poly
MY
i;
MY
MY
Poly
Poly
Poly
Poly
Poly
MY
1;
i;
CerD
CerD
CerD
CerD
Mfr.
Code
Mfr.
Deslg.
Kelthley
Pall No.
Fig.
Ref.
71590
71590
71590
71590
64171
68460
13050
13050
13050
97419
71590
71590
71590
71590
64171
66480
13050
13050
13050
13050
72962
72962
72962
72962
CPR-IBOJ
CPR-660J
CPR-2200J
CPR-6800J
2PJ-223G
3FR-663-l E
SMIA-.22kF
SMlA-.66pF
SMIA-2.2kF
M2WF-6.6pF
CPR-66J
CPR-330J
CPR-IOOOJ
CPR-3300J
2PJ-103G
3FR-333-l E
SMIA-.lkF
SMIA-.33kF
SMlA-IpF
SMl A-~.~FF
DD-050
DD-050
DD-330
DD-101
Cl36-15OP
Cl36-660P
Cl36-.0022M
‘X38-6800P
C108-.022M
Cl46-.066M
C47-.22mF
C47-.66mF
C47-2.2M
C203-6.6M
Cl 36.66P
Cl 38-33OP
Cl 36-,001 M
Cl36-.0033M
Cl06-.OlM
‘2146..033M
C47-.I M
C47-.33M
C47-1 M
C47-3.3M
C64-5P
C64-5P
C64-33P
C64-IOOP
19
19
:i
1:
19
19
16
16
19
19
19
1:
19
1:
;:
;z
19
19
MISCELLANEOUS
Circuit
Deslg.
Type
Mfr.
code
Mfr.
IJesig.
Kelthley
Part No.
ii
19
19
19
2
3
-
Flg.
Ref.
22526
12040
01295
01295
04713
04713
60164
20052
LM30lAN
1N914
1N914
2N3903
2N3905
SW-336
J102
-
Connector, IO-Pin, Mini-PV
Integrated Circuit
Diode, Rectifier
Diode, Rectifier
Transistor
Transistor
Switch, Rotary, RISE TIME
Knob, Rise Time
Connector, ENC. UGl094A/U
Cap, BNC, mates with J102
02660
31-2221
CS-237
IC-24
RF-26
RF-28
TG-49
TG-53
SW-336
KN-46
cs-249
CAP-l 6
Clrcult
Desig.
Value
Rating
Type
Mfr.
Code
Mfr.
Desig.
Keithley
Part No.
RI01
R102
R103
RI04
RI05
7.76kR
6.41 kn
51.7kQ
51.7kn
IOkn
I%,
I%,
l%,
1%.
1-i;
MtF
MtF
MtF
M1F
MtF
07716
07716
07716
07716
07716
CEA-7.76KR
CEA-6.41 KR
CEA-51.7KR
CEA-52.7KR
CEA-1 Om
R66-7.76k
R66-6.41 k
R66-51.7k
R66-51.7k
R66-1 Ok
JlOl
QAIOI
DlOl
D102
a101
a102
SIOI
1/6W
1/6W
1/6W
1/6W
l/SW
Flg.
Ref.
;‘z
29103-c-2
/7-90
Page 22; Replace Table with the following:
AMPLIFIER BOARD (cont’d)
DIODES
Circuit
Deslg.
D201
D202
D203
D204
D205
D206
D207
D208
D209
D210
Type
k
Special
Special
Silicon, NPN, Case TO-106
Silicon, NPN, Case
80164
80164
07263
07263
01295
01295
01295
01295
Silicon
Silicon
Silicon
Silicon
01295
01295
Mfr.
Desig.
Keithley
Part No.
Fig.
Ref.
24555A
24555A
2N3565
2N3565
1N645
1N645
1N914
IN914
1N914
1N914
24555A
24555A
TG-39
TG-39
RF-14
RF-14
RF-26
RF-26
RF-26
RF-28
18
1:
18
16
16
16
18
MISCELLANEOUS
Chult
Deslg.
Mfr.
Code
Mfr.
Desig.
Keithley
Part No.
Fig.
Ref.
i%,:“’
07263
80164
%E
IC-26
SW-337
KN-46
18
18
2
J201
J202
02660
31-2221
cs-249
18
Type
Integrated Circuit, Operational Amplifier.
Switch, Rotary, GAIN
Knob, Gain
Not Used
Receptacle, BNC (UG-1094AIU)
RESISTORS (*Located on Switch 5201)
Circuit
Lhig.
VSIIJS
Rating
Type
Mfr.
Code
Mfr.
Desig.
Keithley
Part No.
Flg.
Ref.
R201
R202
R203
R204
R205
R206
R207
R206
R209
R210
R211
R212
R213
R214
R215
R216
R217
R218’
R219’
R220’
R221’
R222’
R223’
R224
R225
1on
lfvm
1ookQ
23.2kn
22.lkn
IOkn
18.2kR
1ok.Q
12.lkn
499n
4990
1on
47on
1okQ
470R
IOR
ion
270k.Q
1OOR
9000
1ok.Q
1ook.Q
IMn
IOMR
10BR
IO%, 1/4W
IO%, 1/2W
I%, 1/8W.
I%, 1/8W
l%, 1/8W
I%, 1/8W
l%, 1/2w
I%, 1/8W,
I%, 1/8W
I%, 1/8W
I%, 1/8W
1%, 1/8W
IO%, 1/4W,
I%, 1/6W
1O%, 1/4W
lo%, 1/4W,
lo%, 1/4W
lo%, 1/2W
l%, 1/2w
1%, 1/2w
I%, 1/2w,
1%. 1/2w
l%, 1/2w
1%. 1w
l%, 2w
Comp
Comp
MtF
MtF
MtF
MtF
MtF
MtF
MtF
MtF
MtF
MtF
Comp
MtF
Comp
Comp
Comp
Comp
MtF
DCb
MtF
MtF
MtF
DCb
DCb
44855
01121
07716
07716
07716
07716
07718
07716
07716
07716
07716
07718
44655
07716
44655
44855
44655
01121
07716
91637
07716
07716
07718
91637
91637
RC07
ELI-1 M
CEA-100kR
CEA-23.2kR
CEA-22.lkQ
CEA-1 Okn
CEC-18.2kQ
CEA-1 Okn
CEA-12.lkn
CEA-499n
CEA-499R
CEA-1 OR
RC07-471
CEA-IOkR
RC07-471
RC07-100
RC07-100
ES-270kn
CEC-IOOR
DCF-l/2-900n
CEC-IOkR
CEC-IOOkR
CEC-1 Ma
DC-I-IOMR
DC-2-l OQ
R76-10
Rl-IM
R88-1 OOk
R88-23.2k
R88-22.1 k
R88-IOk
R94-18.2k
R88-IOk
R88-12.1 k
R88-499
R88-499
R88-10
R76-470
R88-10k
R78-470
R76-10
R76-10
Rl -270k
R94-100
RI 2-900
R94-10k
R94-100k
R94-1 M
Rl3-IOM
Rl4-IO8
18
18
18
18
18
18
18
18
18
18
1:
18
18
::
29103-c-2 I 7.90
Page 24; Replace Table with the following:
MOTHER BOARD (cont’d)
ClrCUlt
De&g.
TYPe
D306
D309
D310
0311
D312
Silicon
Silicon
Silicon
Silicon
Silicon
DIODES (co&d)
Mfr.
Mfr.
Deslg.
Code
01295
01295
01295
01295
01295
IN914
IN914
IN914
1 N645
IN914
Kelthley
Part No.
Flg.
RF-28
RF-26
RF-26
RF-14
RF-26
17
17
;:
-
Ref.
MISCELLANEOUS
CkUlf
De&g.
TYPO
J301
J302
QA301
DA302
QA303
5301
5302
5303
Connector, Mini-PV
Connector, Mini-PV
Integrated Circuit, Voltage Regulator
Integrated Circuit, Voltage Regulator
Integrated Circuit
Switch, Line Voltage
Switch, “PUSH ON’ Power with lamp
Switch. CURRENT SUPPRESS
Knob Amperes
Transistor
Transistor
Transistor. Silicon, NPN. TO-92 Case
Switch POLARITY
Fuse. tt7V. .25a, Slo-Blo.3AG
Fuse, 234V, IIBA. Slo-Blo, 3AG
Transformer
Receptacle, AC
Line cord. mates with P305
Pilot lamp, neon (replacement for 5302)
Pilot Lamp, OVERLOAD
Knob, Fine Adjust
Q301
Q302
Q303
5304
F301
F301
T301
P30.5
DS-301
DS-302
Mfr.
Code
Mfr.
Deslg.
Ketthley
Ftg.
22526
22526
07263
07263
07263
80164
60164
60164
47439
47439
UGA7723393
UGA7723393
A749C
SW-316
PBL-5-BSA3C7A
SW-339
17
02735
02735
04713
60164
75915
71400
90164
92369
70903
09806
07294
40312
40312
2N3903
SW-236
CS-236
CS-236
IO-26
IC-25
IC-27
SW-316
SW-340
SW-339
KN-46._
TG-54
TG-5*
.-_.
TG-49
SW-236
FU-17
FU-20
TR-136
CS-235
co-7
PL-58
PL-51
KN-58
Ei250
TR-136
AC3G
17256-S
C7A (NE-2P)
CFO3ACSl669
Part No.
Ref.
;:
17
17
3
3
20
2
17
17
17
3
3
;0
3
-
2
2
RESISTORS (*Located on Switch S303)
Aatlng
TYPO
Mfr.
Desig.
Flg.
VdUe
Mfr.
Code
Kelthley
Destg.
R301
R302
R303
R304
R305
R306
R307
R306
R309
R310
R311
R312
R313
R314
R315
R316
R317
R316
R319
R320
R321
R322
R323
R324
R325
634fl
6.2D
1.37k.D
*oo*
1.24kn
634*
6.2n
1.37la
2oon
1.24kQ
9.09ko
14kR
1kfJ
1 OkR
1%. 1/6W
5%, 1/2w
1%. IIBW
0.5w
1%. l/SW
1%. 119w
5%. t /2w
1%. l,QW
0.5w
1%. l/SW
l%, IBW
1%. 1/8W
I%, 1/8W
10%. 1/4w
I%, l/QW
I%, l/BW
I%, 1/6W
I%, 1/6W
1%. 1/6W
10% 1/4w
10%. 114w
IO%, 1/4w
10%. 114w
10%. 114w
1%. 1/2w
MtF
Comp
MtF
MtF
MtF
Comp
M1F
MtF
MtF
MtF
MtF
Comp
MtF
MtF
MtF
MtF
MIF
Comp
Comp
Comp
Comp
Comp
MtF
07716
01121
07716
60294
07716
07716
01121
07716
60294
07716
07716
07716
07716
44655
07716
07716
07716
07716
07716
44955
44655
44655
44655
44655
07716
CEA-6340
EB-6.2n
CEA-1.37kR
3329P-200
CEA-1.1 k.Q
CEA-634n
EB-9.2n
CEA-t.37M
3329P-200
CEA-1 .I Icn
CEA-9.09kR
CEA-14kR
CEA-1 kn
RC07-100
CEA-1 kn
CEA-9.09kR
CEA-1 kn
CEA-1 kR
CEA-14kn
RC07-100
RC07-103
RC07.103
RC07-331
RC07-473
CEC-lOk0
R66-634
RIQ-6.2
R&?-l .37k
RP-98-200
R68-1.24
R98-634
RIQ-6.2
R88-1.371
RP-98-200
R68-1.24
R66-9.09k
R99-t4k
R66-1 k
R76-10
RBB-1 k
RBB-9.09k
RBB-1 k
RBB-I k
R96-14k
R76-10
R76-t0k
R76-IOk
R76-330
R76-47k
R94-10k
17
17
17
17
17
&%n
lk0
IkQ
14kfl
IOCl
1 Okn
1 OkR
33on
47kn
10kQ
Part No.
Ref.
;:
;:
17
17
1:
17
17
;:
17
17
17
;:
17
17
20
29103-C-2 / 7-90
HOW TO
CUT
PIN
5 OF THE
INSTALL
IC-333
IC-333.
ii.
PIN
1 IXF THE
Op AMP
GOES
INTO
THE
HOLE
IOF PIN
2.
8.
PIN
2 OF THE
CIp AMP
GOES
INTO
THE
HOLE
CiF pIN
S.*j:
C.
PIN
3
Op AMP
GOES
INTO
THE
HOLE
OF PIN
4.
D.
PIN
4 OF THE
OP iiw
GOES
INTO
THE
HOLE
OF PIIN
5.
E.
PIN
& OF THE
OP AMP
cc
GOES INTO
THE
HOLE
OF PIN
.5.X+
F.
PIN
7 OF THE
Op AMP
GOES
INTO
THE
HOLE
OF PIN
3.
G.
FIN
3
OF GMF
GOES
INTO
THE
HOLE
OF PIN
10.
PIN
OF THE
OF THE
HOLES
ON THE
REVERSE
c-64-22pF
CIRCUIT
SEE
WILL
SIDE
BETWEEN
CHANGE
REMOVE
1,7,9
R210
OF THE
3 AND
R211
FORM
BOARD.
ATTACHED
C-207,C-203
THEY
ARE
DRAWING.
EMPTY.
PC-&u=“9
FINS
AND
CAPACITORS
REMAIN
INSTkLL
A CAPACITOR
b OF PC BOARD.
R-83-1K
TO
AND
C-20’?
NO LONGER
%*
R-38-3.01K.
NEEDED.
FROM
THE
COMPONENTUYOUTS
MODEL 427
4
rR201-+201
--y-C2031
-
-c107-
FIGURE 18.
component Layout - PC-289.
FIGURE 19.
Component Layout - PC-292.
15