Keithley 244 User manual

INSTRUCTION MANUAL
Model 244
High Voltage Supply
(and Model 2441 Overload Protection Option)
@COPYRIGHT 1976, KEITHLEY INSTRUMENTS, INC.
FOURTH PRINTING, DEC. 1977, CLEVELAND, OHIO, U.S.A.

MODEL 244
CONTENTS
CONTENTS
SWtiO” Page
SPECIFIC.4TIONS .................................... iv
1. GENERAL DESCRIPTION. ............................... 1
2. OPERATION. .................................... 4
3. CIRCUIT DESCRIPTION. ............................... 6
4. ACCESSORIES
.................................... 8
5. REPLACEABLE PARTS. ................................ 13
6. CALIBRATION .................................... 19
SCHEMATICS ...................................... 25
ILLUSTRATIONS
Figure NO. Title Page
1 Model 244 High Volt+ Supply ...................... 1
2 FrOnL Panel Controls. .......................... 3
3 Rear Panel Controls ........................... 3
4 current Limiting. ............................ 5
5 Simplified Circuit Diagram. ....................... 6
6 Overload Protection Cmmectio,, Diagram. ................. 10
7 Overload Protection Circuit Diagram ................... 11
8 Top Cover Assembly. ........................... 15
9 Bottom cover Assembly .......................... 15
10 Circuit for Laad BDX LB-1 ........................ 22
11 Circuit for Divider ""-1. ........................ 22
1176

SI?ECIFICATIONS MODEL 244 HIGH VOLTAGE SUPPLY
SPECIFICATIONS
OUTPUT:
Voltage: -200 to -2200 volts in ZO-volt steps
current: 10 milliamperes maximum
Polarity: Negative with respect Lo chassis
ACCWACY: il% of dial setting
RESOLUTION: A O-25 volt "Trim" porentiameter permits interpolation be-
tween steps with a resolution of better than 100 millivalts.
STABILITY: ~0.005% per hour after a two-hour warm-up; +o.Ol% the first
hour or in subsequent S-hour periods after a one-hour warm-up.
LINE KECULATION: +O.OOl% for a 10% change in line voltage.
LOh" REGULATION: ,O.OOl% for a 5-milliampere load change.
RIPPLE AN" NOISE: Less than 0.5 milli"olt rms above 5 Hz.
OVERLOAD: Electronic current limiting with automatic recovery.
METER: Provides check on OUtpUt voltage.
CONNECTOKS: Output (on rear) MHV series (UC-931/U)
POWER: 105-125 or 210.250 volts (switch-selected); 50-60 Hz; 90 watts.
OIMENSlONS: b-114" high x S-718" wide x l&7/8" deep (158 x 225 x 378 mm)
WEIGHT: net weight, 13 pounds (6,O kg).
ACCESSORIES FURNISMED: Mating Connector (MHV series, UC-932A/U)
iv
1176

MODEL 244 HIGH VOLTAGE SUPPLY GENERAL DESCRIPTlON
SECTION I. GENERAL DESCRIPTION
l-l. GENERAL. The Model 244 is a negative-polarity
high-voltage supply that provides accurate, stable
outpote from -200 to -2200 volts d-c at up to 10 ,,$.
"l~Xi"l"Ul.
1-2. FEATURES.
a. In-line Calibrated Dials.- Two dials set the
output voltage in 200 and ZO-volt steps. Trim Control
permits interpolation between ZO-volt setting, with
100 millivolt resolution.
b. Overload Protection.- Repeated or continuous
overloads will not damage the instr,m,ent. Protection
circuit limits the oucput current to less than 13
milliamperes with automatic recovery when overload is
removed.
c. Stability.- Solid-state design, stable range
resistors, and selected zener diode provide voltage
stability of +0.005% for B-hour periods after one-
hour warm-up.
d. Model 2441 Overload Protection Option.- A,,
optional protection circuit is available (on special
order) which can be used to limit the current of the
Model 244 when monitored by e Keithley picoammeter
such es the Model 414A.
1-3. APPLICATIONS.
a. The Model 244 has bee,, designed primarily for
negative-polarity high voltage biasing for photo-
multiplier applications.
b. The stability, regulation and low noise also
make it suitable for use with photocells, ion chambers
and resietiviey measurements.
0870 1

GENERAL DESCRIPTION MODEL 244 HIGH VOLTAGE SUPPLY
COntrOl
OWERSwitch (S102)
TABLE 1-l.
Front Panel Controls.
Functional Description
Controls the a-c line power to all circuits.
Paragraph
2-2e
OWERON indicator (mlol) Pilot light glows orange when Power Switch is ON.
z-2f
UTPUT Switch (5101) Controls the a-c power to the high voltage section. 2-2g
oltwe Dials (s103, s104)
sets oueput voltage from -200 to -2ml volts. 2-b
rim Control (R146) Permits interpolation between steps with O-25 volts maximum trim.
2-a
VBRLOAD Indicator Pilot light glows when output current exceeds 11 I&. approximately.
2-3~
,eter (MlOl)
Indicates the magnitude of selected voltage.
2-3a
Control
TABLE 1-2.
Rear Panel Connections.
Functional Description Paragraph
OUTPUT Receptacle (5101) VOl tage o"tp"t 2-la
117V/234V Switch (5103) Sets instrument far either 117 or 234 " a-c power. Z-lb
Fuse (FlOl) 117" operation: 3/4A, slow-blow.
234 Operatim: 3/&I, slow-blow.
2-k
Overload Input (Cover) Cover plate for optional Model 2441 installation. 2-k
2 0770

0”tpllt
Selector
Switch
(SlO3)
output
Selector
switch
(X04)
(MlOl) Switch indicator Indicator
(SlOl) (DS102) (OSlOl)
FIGURE 2. Front Panel Controls.
Switch
(5102)
117/234V F"LTC5 (COWS) OUTPUT
Switch (FlOl) Overload Receptacle
(5103) Input (J")l)
z.rnrmm I) "_^_ n--.7 "~~~-.-_,~
0770 3

OPERATION MODEL 244 HIGH VOLTAGE SUPPLY
SECTION 2. OPERATION
2-1. CONNECTIONS.
a. Output Receptacle.- A rear panel mounted MHV
teflon-insulated receptacle provides connection to
the load circuit. The outer shell of the receptacle
is connected to chassis.
b. Coaxial Cables.- Use coaxial cables which are
rated for greater than 2200 volts for safe operation.
Coaxial cables provide best noise immunity for criti-
cal meaeurements.
C. Earth Ground.- For maximum operator safety use
the 3-wire power cord with third wire solidly connec-
ted to earth ground.
2-2. PRELIMINARY PROCEDURES.
a. The instrument is shipped in operating condition
+ith all components installed for immediate use.
b. Set the 117-234 volt switch for operating line
voltage.
C. Check the fuse for proper type and rating.
d. Provide adequate ventilation for the instrument.
Air flow should be maintained along the top and bottom
surfaces.
NOTE
If air flow is constricted the internal
temperature will rise above normal design
limits causing degradation of critical
components.
e. Set the front panel controls as follows:
POWERSwitch Off
Voltage Dials 2-o-o
OUTPUT Switch Off
f. Connect the line cord and set the POWER
Switch to ON. (The POWERindicator should
be lighted.)
NOTE
The meter should indicate 0 KILOVOLTS.
g. After a preliminary one minute warmup period,
p&ace the OUTPUT Switch to ON position. Allow another
warmup period (30 minutes) for the high voltage sec-
tion to stabilize. The meter should indicate approx-
imately one minor division or 200 volts.
2-3. OPERATING CHECK-OUT.
a. Meter Indication.- When the OUTPUT Switch is ON
the meter should indicate the dialed voltage.
b. Output Voltage.- Connect an accurate voltmeter
such as Keithley Model 153 to the output to verify
the power supply voltage accuracy. The Trim Control
should be set to CAL position. measure the Model 244
output for dial settings of 200,,,500, and 1000 volts.
Accuracy should be 21% of dial setting.
c. Current Limit.- (Refer also to paragraph 2-5
for a more complete discussion of the overload current
operation.)
1. Connect an accurate ammeter such as a Keith-
ley Model 153 in series with an adjustable resis-
tance decade box. Set the dialed voltage on the
Model 244 at -200 volts with the OUTPUT Switch
"OFF". Apply the -200 volt output to the resistance
decade box set at 20 kilahms. The ammeter should
indicate 10 mA when the OUTPUT Switch is placed
nON". The OVERLOADIndicator should not be lighted.
Decrease the resistance load until the OVERLOADIn-
dicator is lighted. The annneter should indicate
between 11 mA and 12 n!A.
NOTE
Resistor load power dissipation is approx-
imately 2.2 Watts.
2. Connect an ammeter and 50 kilohm resistive
load to the output of the Model 244. Set the dial-
ed voltage an the Model 244 at -200 volts with the
OUTPUT Switch "OFF". Place the OUTPUT Switch to
"ON" position. Reduce the load to zero ohms (short
circuit) and measure the output current. The
ammeter should indicate less than 14 milliamperes
with the Model 244 OVERLOADIndicator lighted.
2-4. SETTING OUTPUT VOLTAGE. The setting of the
Voltage Dials and Trim Control determines the magni-
tude of the output.
a. The two Voltage Diala set the output from -200
to -2200 volts d-c in calibrated 200 and 20-volt
steps. With the Trim Control in CAL position the
output is set by the Voltage Dials within specified
kXC"K%Y.
b. The Trim Control interpolates between 20-volt
settings with 100 millivolt resolution. The Trim
Control range is 0 to 25 volts.
4 0770

MODEL 244 HIGH VOLTAGE SUPPLY OPERATION
2-5. OVERLOADPROTECTION.
a. The Model 244 has an overload current limiting
circuit which limits the output short-circuit current
to a maximum 14 milliamperes. The circuit is adjusted
so that the OVEKLOADIndicator will be lighted when
the output current exceeds 11 milliamperes. When the
overload is removed the Model 244 will automatically
reset to normal operation and the OVERLOADIndicator
will turn off.
b. Current Limiting Characteristic.- The Model 244
current limiting is shown graphically by the typical
V-I characteristic curves in Figure 4. The OVERLOAD
Indicator is factory-adjusted to turn on at approxi-
mately 11 milliamperes. However the output voltage
remains constant for current exceeding 11 milliamperes
as shown. The current limiting occurs typically from
11.3 to 12.2 milliamperes depending on the dialed
voltage.
0 10 12
f .
I
14 mA
FIGURE 4. Current Limiting.
c. Model 2441 Overload Protection Option.- An
optional protection circuit is available which can
bz used to limit the current of the Model 244 when
w>nitored by a Keithley picoammeter such as the
I!zrdel 414A. Consult your Keithley representative or
t:,e Sales Service Department for further information
regarding the Model 2441 Option.
2-6. CAPACITIVE La4ix.
a. When a capacitive load is connected to the out-
put, Model 244 will deliver a charging current up to
14 milliamperes maximum until the dialed voltage is
developed across the load. During the charging time
the OVERLOADIndicator will be lighted as long as the
output current exceeds 11 milliamperes. The OVERLOAD
Indicator will turn off automatically when the charg-
ing current is reduced to less than 11 milliamperes.
b. Before reducing the dialed voltage with large
capacitive loads (exceeding 1 joule of energy), set
the OUTPUT Switch to “OFF”. Readjust the dialed
voltage and set the OUTPUT Switch to “ON”.
NOTE
A resonant condition (with increased output
noise) could result for large capacitive
loads. If this should occur, change the
load capacitance slightly to remove the
resonant condition and reduce the output
noise.
2-7. OUTPUT NOISE. The Model 244 output ripple and
noise is less than 0.5 millivolt rms above 5Hz with
maximum load. The output noise is typically 200 WV
rms ~with no load. Transient power line noise will
tend to increase the output noise.
2-8. SHORT-TERM STABILITY. The Model 244 stability
is specified to be + 0.005% per hour worst-case after
a two-hour warm-up. After warm-up, the short-term
stability is typically 0.003% per hour for constant
line voltage, load, and ambient temperature.
2-9. TEMPFJATURE COEFFICIENT. The temperature co-
efficient is typically 30 PPM1 C (with a maximum
temperature coefficient not to exceed 60 ppml C).
1176 5

CIRCUIT DESCRIPTION
MODEI: 244 HIGH VOLTAGE SUPPLY
SECTION 3. CIRCUIT DESCRIPTION
3-1. GENERAL.
a. The Model 244 High Voltage Supply haa been
designed to provide a,, accurate voltage from -200
to -2200 volts d-c. A simplified circuit diagram is
shown in Figure 5.
b. The Model 244 is composed of high and low volt-
age supply sections and various other circuits for
control and overload protection. These circuits in-
clude the following.
selected by the front panel dials which control the
voltage divider. The error amplifier senses any
difference between the voltage across the divider
string (which is connected to the output) and the
fixed reference supply. The amplified difference
drives the series regulator circuit to correct the
output voltage. The overload circuit senses the out-
put load current and controls the current within
design limits. This circuit also provides an over-
load indication.
1. High voltage supply.
2. LOWvoltage supply.
3. Series high voltage regulator.
4. Error amplifier.
5. Reference supply.
6. Overload circuit.
7. Voltage Divider.
3-2. HIGH VOLTAGE SECTION. The high voltage is de-
veloped by a voltage doubler circuit composed of
diodes 0101, DlC2, DlC3, and 0104 and fileer capaci-
tars Cl13 and C114. The filtered d-c voltage (approx-
Fmaeely 3200 volts) is applied between the - OUTPUT
and the anode of the series pass element (tube VlOl).
The high voltage section is controlled by the OUTPUT
Switch SlOl which provides ON/OFF control of the a-c
C. Over-all Operation. The output voltage is power to transformer TlOl.
R
H
WWER LDAD
LAMP UMP I
FIGURE 5. Simplified Circuit Diagram.
6 0770

MODEL 244 HIGH VOLTAGE SUPPLY
CIRCUIT DESCRIPTION
3-3. SERIES HIGH VOLTAGE REGULATOR. The series regu-
lator tube VlOl is biased by the collector voltage of
transitor QlOE to form a “cascade amplifier” with the
output load serving as the plate resistor. The Model
244 - OUTPUT is effectively the algebraic sum of the
unregulated high voltage (3200 V) and the drop across
“101 and QlOE. When the OUTPUT Switch SlOl is off
(e.g. no plate voltage is on “101) the voltage at pin
8 (Screen Voltage) of VlOl will be significantly less
than nominal + 95 volts since the tube current will
cause a voltage drop across R169.
3-4. VOLTAGE CONTROL. The output voltage is divided
by a resistor divider composed of resistors R146
through R167 located an switches S102, 5103, and S104.
The sampling voltage is compared with the reference
supply voltage. (The reference supply is composed of
zener D119 and resistors Rl40 through R145). The
difference voltage is amplified by the error amplifier
(transistors QllO, Qlll, Q112, and Q113) which drives
cathode biasing transistor ~108. Diodes 0114 through
Dl17 and resistors R115, R117, R139, and R144 protec?
the comparator and zener reference from switching
transients when the output is changed. Diode Dill
prevents a reverse bias on transistor QlOV beyond its
breakdown voltage.
3-5. CURRENTCONTROL,
a. The output current is sensed by measuring the
voleage drop across resistor R124. A current limit
amplifier consisting of Q107 controls the error am-
plifier through diode D112. When the current through
R124 exceeds approximately 11 milliamperes, transistor
Q107 forward biases D112 and turns off the error am-
plifier which reduces the Model 244 through the action
of VlOl.
b. Overload Indication.- The OVERLOADIndicator
05102 is driven by transistors 4104, Q106, and Q107.
Transistor QlO5 is an emitter-follower which biases
9106 to insure that the OVERLOADIndicator turns on
before the current limiting actually occurs. (The
OVERLOADIndicator is designed to turn on at approx-
imately 11 milliamperes load current.)
3-6. LOWVOLTAGE SECTION. The low voltage for the
control circuitry is obtained from a full-wave rec-
tifier composed of diodes D109 and I1110 and filter
capacitor c115.
a. + 95 v d-c. This voltage is applied to a bias
screen on “101. The + 95 v is developed across R113
and D105.
b. + 20 v d-c. This voleage is regulaeed by zener
diode D105. A regulated current sowce (25~) supplies
a constant current far zener diodes D105 and D106.
The current source is composed of transistors QlOl,
9102, and Q103 and reference zener D107. The regulated
current is sampled at R116 and compared to zener 0107
by transistor Q102. The action of QlOl and Q102
regulates the currene through 0105, D106, and R113.
c. - 10 v d-c. This voltage is regulated by zener
diode 0106.
NOTE
The a-c power to the high and low voltage
sections is controlled by the POWERON
Switch ~102. The POWERON Indicator
ix101 is driven by the low voltage d-c
SUPPlY.
0770 7

ACCESSORIES MODEL 244 HIGH VOLTAGE SUPPLY
SECTION 4. ACCESSORIES
4-l. GENERAL. The following Keithley accessories can 4-2. OPERATING INSTRUCTIONS. A separate Instruction
be used with the Model 244 to provide additional co"- Manual is supplied with each accessory giving complete
venience and versatility. operating information.
Model 4003A Rack Mounting Kit
Description: Parts Liar:
The Model 4003A is a rack mounting kit with overall
dimensions, 5-l/4 inches hFgh x 19 inches wide. Two
cop covers are provided for use with either 10 inch or
13 inch deep instruments.
Application:
The Model 4003A converts the instrument from bench
mounting to rack mounting. It is suitable for mount-
ing one instrument Fn one-half of a standard lY-inch
rack.
Item
NO.
Qty. ,Per
Keithley
Assemblv Part No.
1 Top cover, 10" 1 18554B
2 Panel Adapter Plate 1 17452B
3 Angle Support 1 17476A
4 Screw, ii10 x 318" 4 ---
5 Connecting Place 1 191268
6 Screw, #lo x 112" 4 -_-
7 Angle 1 14624B
8 Top Cover, 13" 1 20015B

MODEL 244 HIGH VOLTAGE SUPPLY ACCESSORIES
Model 4004A Dual Rack Mounting Kit
Description: parts List:
The Model 4004A is a rack mounting kit with overall
dimensions, 5-l/4 inches high x 19 inches wide. Two
top covet-~ are provided for use with either 10 inch
or 13 inch deep instruments.
Application:
The Model 4004A converts the instrument from bench
mounting to rack mounting. It is suitable for mount-
ing two inseruments in a standard 19-inch rack.
Item
NO. Description Qty. Per Keithley
Assembly Part No.
1 Top cover, 10"
4 screw, #lO x l/2
5 Connecting Plate
6 screw, (110 x l/2
7 Angle
8 Top Cover, 13"
9 Zee Bracket
10 Plate (not shown)
185540
19126A
___
14624B
20015B
1914411
174548

ACCESSORIES MODEL 244 HIGH VOLTAGE SUPPLY
Model 2441 Overload Protection Option
Description:
The Model 2441 when factory installed on the Model
244 provides automatic current limiting of the Model
244 output.
Specifications:
OVERLOAD: Model 2441 circuitry provides automatic
current limiting of the Model 244 when the over-
load input voltage to the Model 2441 exceeds
approximately +1.4 volts.
SENSITI"IT:T: An overload input voltage from +1.4V
to +2.OV (+1.7 volts typically) will cause cur-
rent limiting of the Model 244 output.
OVERLOADINDICATIONS: The overload lamn will indi-
Typical Operation: NOTE
The picaammeter (such as Model 414A) has a 1
volt output for full scale input on the range
selected. If the current monitored by the
Model 414A increases to approximately 170% of
full scale the Model 414A output,of the 1.7
volts will activate the Model 2441 circuit.
Any further increase in the current monitored
by the picoammeter will ultimately be limited
to no more than 200% of the full scale range
of the picoammeter. However current limiting
of the Model 244 will occur whenever the Model
244 output exceeds 11 milliamperes s the Model
2441 is activated.
cate whenever rhe Model 244 is in a current
limiting mode. NOTE
The Model 244 will deliver a calibrated
voltage as long as the overload lamp is off
(or the overload input voltage does not
exceed +1.2 volts).
a. Connect the recorder output of a Keithley
picoammeter such as the Model 414A or equivalent to
the Overload Protection Input receptacle 5201. see
Figure 1.
b. Select the full scale current range an the
picoammeter for desired operating range.
c. Recorder output of 414A should be in 1 volt
NOISE IMMUNITY: An 8V p-p at 60 Hz overload input mode.
signal will not operate overload.
RESPONSETIME: Time for a 2.5" Peak pulse to acti-
"ate 2441 is typically 0.25 seconds (lo-go%).
d. Operate the Model 244 as described in gecrion
2.
I
MODEL 244-2441
r-l
PICOAMMETER
MODEL 244-2441 PICOAMMETER
I
System
T Ground
FIGURE 6. Overload Protection Connection Diagram.
10 0976

MODEL 244 HIGH VOLTAGE SUPPLY
ACCESSORIES
Theory of operation far Model 2441:
(See Schematic
24640A.)
a. The Model 2441 Option provides current limiting
control when used with a ,,icoammeter with a 1 volt
output. The Overload Protection Input 5201 requires
an input signal between 1.4 to 2.0 volts d-c. The
Model 2441 circuit activates the Model 244 control
circuit by meant of transistor switch Q202. The
Model 2441 filter circuit prevents false overloads
due to 60 Hz noise while not affecting the response
which is approximately 0.25 seconds (10-W% rise
the).
b. 'rhe 2441 Circuit is composed of an emitter
fallower transistor Q201 which drives a transistor
switch Q202 which is paralleled wieh the Model 244
overload transistor switch 4107. A filter circuit
is composed of R203 and C2Ol.
Replaceable Parts for Model 2441:
C*l-C"it Mfr. Mfr. Keithley
oesig. oescription Code oesig. Part NO.
5201 COll"eCtOr APH so-PC2M
a-233
-- Cable, 3 ft., k&es
with 5201) K-I -- 3991
Q201 Transistor F-I
2N3565 'i-G-39
Q202
Transistor F-l
2N3565 'K-39
R201 Resistor,lMn,l0%,1/2W A-B EB Rl-1M
R202 Resistar.3.9Kn.l0%.1/2W A-B EB Rl-3.9K
R203 ~~~~~~~~~ m,io%,i/2w ~-8 EB n-x
R204 Resistor, 10Kn,10%,1/2W n-B EB Rl-1OK
R205 Resistor,100K~,10%,1/2W h-B EB Rl-100K
c201
Capacitor, 22ufd,20" u-c
K22JZOK CSO-2x4
-_ Stand off K-I --
ST-25
5107 COll”eCt’X K-I -- SpCXid
FlClmE 7. Overload Protection circuit Diagram.
0976

ACCESSORIES
MODEL 244 HXH VOLTAGE SUPPLY
MH” connector, cs-191
D~SCt-ipfiOll: Application:
TL- mv ~..-..~~~nr o..nnli~A ...lrh the instrument is a The connector should be used with low noise coaxial
------TOT. This part cables such as RG58A/U or RG59/U. The cable size
Il. used with this connector should not exceed .257in. 0.1)
Assembly Instructions:
4. Solder contact to center conductor.
5. Slide back end p.rts forward then
thread assembly into connector and
lock securely. “ee qmket must be
split by brald clamp.
3. Fold brald back over brald clnp and
trim .I ,kwn. Cut dlelectrlc and center
conductor to 7/W’ dimension then
strip dlelsctrlc to .470 dimension.
12 0870

MODEL 244 HIGH VOLTAGE SUPPLY
SECTION 5. REPLACEABLE PARTS
REPLACEABLE PARTS
5-l. REPLACEABLE PARTS LIST: This section contains t”rer’s Part Number, and ehe Keithley Part Number.
a list of camponen~s used in this instrument for user Also included is a Figure Reference Number where
reference. The Replaceable Parts List describes the applicable. The complete name and address af each
individual parts giving Circuit Designation, Descrip- Manufacturer is listed in the CODE-TO-NAME Listing
tion, Suggested Manufacturer (Code Number), Manufac- following the parts list.
TABLE 5-l.
Abbreviations and Symbols
A i ampere
Cb”ar : Carbon Variable
cem : ceramic oisc
Cer Trimmer ; Ceramic Trimmer
Chip : composition
: Deposit
DCb : Deposited Carbon
Desig. : Designation
EAL i Electrolytic, Aluminum
ETB : Electrolytic, tubular
ETT i Electrolytic, tantalum
F i farad n ; ohm
Fig : Fig”?-+ P pica (10-'2)
GCb i Glass enclosed Carbon PC i
: Printed Circuit
POly
k kilo (10-3) ; Polystyrene
Ref. : Reference
P micro (10.6) TC”
M ~~~ (106) i Tinner Copperweld
Manufacturer ” : valtMfr. i
MtF : Metal Film
MY Mylar W : watt
ww
NO. Number i Wirewound
ww”ar : Wirewound Variable
5-2. ELECTRICAL SCHEMATICS AND DlAGRANS. Schemaeics Sales Service Department, Keithley lii~truments, Inc.
and diagrams are included to describe the electrical or your nearest Keirhley representative.
circuits as discussed in Section 3. Refer to Table
5-2 which identifies all schematic part numbers b. When ordering parts, include the following in-
included. formation.
5-3. HOWTO “SE THE REPLACEABLE PARTS LIST. This
Parts Lise is arranged such that the individual types
Of components are listed in alphabetical order. The
parts for the instrument’s Main Chassis are listed
followed by printed circuit boards and other sub-
assemblies.
5-4. HOWTO ORDERPARTS,
a. Replaceable parts may be ordered through the
1. Instrument Model Number.
2. Inserument Serial Number.
3. Pare Description.
4.. Schematic Circuit Designation
5. Keithley Part Number.
c. All pares listed are maintained in Keithley
spare Parts Stock. Any part not listed can be made
available upan request. Parts identified by the
Keithley Manufacturing Cade Number 80164 should be
ordered directly fram Keithley Instruments, Inc.
TABLE 5-2.
Circuit Designaeion
Schematic Part Number
Power supply PC-270 243173
0870 13

REPLACEABLE PARTS
MODEL 244 HIGH VOLTAGE SUPPLY
TABLE 5-3.
Mechanical Parts List
Description
1) Chassis
11) Fro,e Panel
Top Cover Assembly
12) Cover, Sheet Metal
13) screws
Handle Assembly
14) Handle
15) Screws #6-32x3/8" R. H. Slotted
Bottom Cover Assembly
2) cover
3) Fastener
Feet Assembly
4) Feet
5) Ball
6) screws #8-32x3/8” Phillips, Pan Head
Tile Bail Assembly
7) Bail
8) Right Assembly
9) Left Assembly
10) Screws 1/6-32x1/4” Phillips, Pan Head
Qll.%ltity
Per Assembly
1
1
___
1
4
___
1
2
__-
1
2
-_-
4
4
4
___
1
1
1
2
Keithley
Part NO.
24304C
24306C
19057
19055c
W-18
___
190628
FA-54
___
FE-5
FE-6
___
171470
19206B
192058
-__
Fig.
7
637
6
6
7
7,
7
14 1176

MODEL 244 HIGH VOLTAGE SUPPLY REPLACEABLE PARTS
FIGURE 8. To,, Cover Assembly.
I
-
1176 15

REPLACEABLEPARTS
MODEL 244 HIGH VOLTAGE SUPPLY
Cl16
Cl17
0.1 IIF
0.1 !JF
0.1 VF
0.1 !lF
.02 UP
0.1 UP
0.1 UF
22 PP
33 PF
.02 PF
100 PP
0.1 !lF
1.0 UP
1.0 UP
40 !lF
0.1 PP
0.1 "F
15”
15"
15"
15"
600"
250"
250"
600"
600"
600"
600"
4OOOV
2000"
2000"
350"
4ooov
250"
890159 c93-.lM
890159 c93-.lM
890159 c93-.l.M
890159 C93-.lM
SW.02 C22-.02M
CZJOAE Cl,&.lM
C28OAE C17G.l"
ED-47 c22-22P
ED-33 cx-3%
ED-.02 C22-.02M
ED-100 CL*-1OOP
LQ40104X c192-.lM
LQ20105X c191-lM
LQ20105X C191-lM
TVA1611 C23-40M
LQ40104X c192-.lM
CiSOAE C178-.1M
5104
5105
5106
5107
5108
___
connector, ~lnl-P" (Solde
connector, Mini-P" (Solde
connector, mini-P" (S&de
Receptacle, female
Connecfor, male (mate far J108)
BRG 20052 lx-237 3
Bps. 47439 E-236 10
BRG 47439 CS-236 10
BRG 47439 CS-236 10
BRG 47439 cs-236 10
BRG 47439 cs-236 10
10
K-I 246588
APH UG93l/V cs-190 io
Am "G-932AIU cs-191 10
Mfr. Mfr. Keichley Fi.g .
Code Part NO. Pare NO. Ref.
S-T 3CFS25
RF-49 10
S-T 3CFS25 RF-49 10
S-T 3CFS25 RF-49 IO
S-T 3CFS25 RF-49 10
ITT Z"20 m-25 10
DIG 1N302OA m-39 10
DIG lN713 m-14 10
T-I 18645 w-14 10
MOT lN4006 RF-38 10
MOT IN4006 RF-38
T-I lA645 RF-14
T-I IN645 RF-14
T-I lN914 RF-28 >
T-I lN645 RF-14
T-1 lN645 w-14
T-I IN645 RF-14
MOT IN4006 RF-38
MOT UT4006 RF-38
MOT IN938 Z-6
S-T vR47 25725A