Fluke 4265A User manual

If=lukei
Instruction Manual
Vali •'tionics International, Inc
•'^00 ^-0258
Wrtwl Ek COPY
Model
4265A
Binary Programmable
Power Source
P/N 310631 JANUARY 1973
REV. 12/76

LIMITED WARRANTY
The JOHN FLUKE MFG CO.. INC., warrants each instrument it manufactures to be free from defects in material and workmanship under
normal use and serviced the period of one year from date of purchase. This warranty extends only to the original purchaser. This
warranty shall not apply to fuses, disposable batteries (rechargeable type batteries are warranted for 90 days), or any product or parts
which have been subject to misuse, neglect, accident or abnormal conditions of operations.
In the event of failure of aproduct covered by this warranty. John Fluke Mfg. Co.. Inc., will repair and calibrate an instrument returned to
an authorized Service Facility within one year of the original purchase; provided the warrantor sexamination discloses to its satisfaction
diaUhe product was defective. The warrantor may. at its option, replace the product in lieu of repair. With regard to any mstrument
retu rned within one year of the original purchase, said repairs or replacementwill be made without charge. If the fault has been caused by
misuTneglect accident or abnormal conditions of operations, repairs will be billed at anominal cost In such case, an estimate will be
submitted before work is started, if requested.
ANY IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS SHALL BE LIMITED TO APERIOO OF
TOELVE MONTHS FROM THE DATE OF PURCHASE. THE FOREGOING WARRANTY ISIINILIEU OF ALL
OTHER WARRANTIES EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY IMPLIED
WARRANTY OF MERCHANTABILITY. FITNESS OR ADEQUACY FOR ANY PARTICULAR PURPOSE OR
USe johHN FLUkI MFG. CO.. INC. SHALL NOT BE LIABLE FOR ANY SPECIAL. INCIDENTAL OR
CONSEQUENTIAL DAMAGES, WHETHER IN CONTRACT. TORT OR OTHERWISE.
NOTE- Some states do not allow limitations on how long an implied warranty lasts, or the exclusion or limitation
of incidental or consequential damages, so the above limitations or exclusion may not .
'
*°'»»“• ™s
warranty gives you specific legal rights, and you may also have other rights which vary from state to state.
It any fault develops, the following steps should be taken:
iNotifv the John Fluke Mfg Co. Inc. or nearest Service facility, giving full details of the difficulty, and include the Modelnumber.
typedumber, and serial number. On receipt of this information, service data or shipping instructions will be forwarded to you.
2. On receipt of the shipping instructions, forward the instrument, transportation prepaid. Repairs will be made at the Service
Facility and the instrument returned, transportation prepaid.
SHIPPING TO MANUFACTURER FOR REPAIR OR ADJUSTMENT
SSSESSSSS
shock-absorbing material.
CLAIM FOR DAMAGE IN SHIPMENT TO ORIGINAL PURCHASER
The instrument should be thoroughly Inspected Immediately upon original
by the customer.
Netherlands.
-For European customers, Air Freight prepaid.
John Fluke Mfg. Co., Inc. •P.O. Box 43210 •Mounllake Terrace, Washington 98043
Rev. 12/77

4265A
Table of Contents
SECTION TITLE PAGE
1INTRODUCTION AND SPECIFICATIONS 1-1
i-l. Introduction 1-1
1-
6. Specifications 1-2
2OPERATING INSTRUCTIONS 2-1
2-
1. Introduction 2-1
2-3, Shipping Information 2-1
2-6. Input Power 2-1
2-8, Rack Installation 2-1
2-10. Operating Features 2-3
2-12. Operating Notes 2-3
2-
24. Programming Information 24
3THEORY OF OPERATION 3-1
3-
1. Introduction 3-1
3-3. Fundamental Circuit Description 3-1
3-5. Block Diagram Analysis 3-2
3-
14. Circuit Descriptions 3-3
4MAINTENANCE 4-1
4-
1. Introduction 4-1
4-3. Service Information 4-1
4-6. General Maintenance 4-1
4-13. Maintenance Access 4-1
4-15. Calibration Procedures 4-2
(continued on page ii)
i

426 5A
TABLE OF CONTENTS, a>nmiuet/
SECTION TITLE
5LIST OF REPLACEABLE PARTS
5-1 Introduction
54 Parts List Column Descriptions
5-5 Manufacturers' Cross Reference List Column Descriptions .. .
5-6 How to Obtain Parts
5-
9Serial Number Effectivity
6OPTIONS AND ACCESSORIES
6-
1Introduction
6-3 Option Information
6-5 Accessory Information
Model A4200 Manual Control Unit
Schematic Diagram A4200-1000
Option -09, Multi-Strobe Isolated Logic
Schematic Diagram 4200-1024 (2 sheets)
Schematic Diagram 4200-1025
Rack Mounting Fixtures
Program Connector
Extender PCB assembly and Cable Extender Assembly
7GENERAL INFORMATION
8SCHEMATIC DIAGRAMS
A1 Mother Board/A7 Binary Display 4265A-101
1
4265A-1013
A2 Power Supply/ A10 Connector Board 42S0A-1061
4250A-1012
A3 Preamplifier 426SA-1051
A4 Option -03, External Reference 4210A-1041
AS Binary Ladder 42 16A- 1031
A6 Isolated Control Logic (2 sheets) 4275A- 1021
A8 Option —06, Programmable Current Limiter 4250A- 1081
A9 Power Amplifier 4250A- 1071
2/75
ii
PAGE
5-1
5-1
5-1
5-2
5-2
5-
3
6
-
1
6-1
6-1
6-1
7-
1
8
-
1

static awareness
AMessage From
John Fluke Mfg. Co., Inc.
Some semiconductors and custom IC's can be
damaged by electrostatic discharge during
handling. This notice explains how you can
minimize the chances of destroying such devices
by:
1. Knowing that there is aproblem.
2. Learning the guidelines for handling them.
3. Using the procedures, and packaging and
bench techniques that are recommended.
The Static Sensitive (S S)devices are identified in the Fluke technical manual parts list with the symbol
<S>
The following practices should be followed to minimize damage to S.S. devices.
2. KEEP PARTS IN ORIGINAL CONTAINERS
UNTIL READY FOR USE. 4. HANDLE S.S. DEVICES BY THE BODY

5.
USE ANTI-STATIC CONTAINERS FOR
HANDLING AND TRANSPORT
6.
DO NOT SLIDE S.S. DEVICES OVER
ANY SURFACE
7.
AVOID PLASTIC, VINYL AND STYRAFOAM
IN WORK AREA
8. HANDLE S.S. DEVICES ONLY AT A
STATIC-FREE WORK STATION
9. ONLY ANTI-STATIC TYPE SOLDER-
SUCKERS SHOULD BE USED.
10. ONLY GROUNDED TIP SOLDERING
IRONS SHOULD BE USED.
Anti-static bags, for storing S.S. devices or pcbs
with these devices on them, can be ordered from the
John Fluke Mfg. Co., Inc.. SeesectionSin any Fluke
technical manual for ordering instructions. Use the
following part numbers when ordering these special
bags.
John Fluke
Part No. Bag Size
453522 6" x8"
453530 8" x12"
453548 16” x 24"
454025 12" x15"

426 5A
Section 1
Introduction &Specifications
1-1. INTRODUCTION
1-2. The Model 4265 Ais aprogrammable, bipolar dc
voltage source. Output voltage is from 0to 65.532 vdc in
two ranges; 16 and 65 vdc. Programming resolution using
the internal reference voltage is 1mv on the 16 volt range
and 4mv on the 65 volt range. Output accuracy is ±.01%
of the programmed level on both voltage ranges. After a100
/£ec settling time, aREADY/NOT READY FLAG indicates
that the output has settled to ±.01% of the programmed
increment for aresistive load. The output current is rated
at ±1 ampere maximum and is limited to approximately
±1.1 ampere in the event of an overload or short circuit.
The sink current (milliamps) is rated at 1000-10 Eout max-
imum. AProgrammable Current Limiter (Option -06) is
available to allow programming the maximum output cur-
rent to a lower level. Acurrent limit flag indicates when a
sink or source current overload exists with or without the
-06 Option.
1-3. Programming requirements are compatible with
DTL or TTL logic levels. Contact or relay closures can also
be used. The voltage source is programmed on the low
range using straight binary coding. The high range is also
programmed in the same manner, but the actual output is
four times the programmed level. Two’s complement cod-
ing is required for negative outputs when the Isolated Con-
trol Logic (-01 Option) is installed. All programming in-
puts and flag outputs are available through a50 pin Am-
phenol, Blue Ribbon connector located on the rear panel. A
+5 vdc output is also available at this connector and is used
to provide power for external programming circuitry. Nega-
tive logic is employed for programming. The logic levels
i
are as follows:
Logic “0” =+2.0 vdc to +5.0 vdc or open circuit
Logic lT* =0to +0.4 vdc or short circuit to
LOGIC GRD.
1-4. Three options are available to provide tailoring
of the power supply to fit application requirements. These
options are identified by numeric designations -03, -06,
and -09. Adescription of each option is provided in
Table 1-1. These options may be installed at the factory
when the instrument is ordered or in the field at alater
time.
1-5. Physically, the power source is completely solid
state. Plug in printed circuit boards, with easy to reach
test points and adjustments, are used for ease in servicing.
The unit is forced air cooled. This results in lower com-
ponent temperatures and thus higher reliability than would
normally be obtained in asource of this power capability.
The chassis is designed for bench top use, or it can be instal-
led in astandard equipment rack by using the Accessory
Rack Mounting Fixtures.
2/75 1-1

4265A
Table 1-1. OPTIONS
OP-
TIONS TITLE DESCRIPTION
-01 ISOLATED CONTROL LOGIC
(Now Standard)
Separates the external digital interface logic and attendant noise from
the Model 4265A analog circuitry. Impedance between the interface
logic and the analog circuitry is greater than 109ohms, in parallel with
3pf, It also provides adata storage that allows multiplexing of several
voltage sources from one system interface register or data bus. Two's
complement binary coding is required for negative outputs.
-02 FRONT PANEL DISPLAY
{Now Standard)
Lamps (light emitting diodes) installed on the front panel which indi-
cates the programmed VOLTAGE LEVEL, SIGN, CURRENT LIMIT,
EXT REF, POWER ON, and STDBY conditions.
-03 EXTERNAL REFERENCE
(Field Installable)
Allows the use of an external signal source in place of the internal refer-
ence voltage. Any dc or ac signal can be used that has an amplitude
from 0 to ±14.5 volts and afrequency from dc to 30 kHz. Input im-
pedance is 100K, in parallel with 70 pf.
-04 DIRECT COUPLED CONTROL
LOGIC
(No Longer Available)
The Direct Coupled Control Logic is no longer offered as an option to
the 4200 series instruments. The Isolated Control Logic (see descrip-
tion above) is now standard equipment on alt instruments.
-05 BLANK FRONT PANEL
{No Longer Available)
The Blank Front Panel is no longer offered as an option to the 4200
series instruments. The Front Panel Display (see description above) is
now standard equipment on all instruments.
-06 PROGRAMMABLE CURRENT
LIMITING
(Field Installable)
Programmable current limit is provided in two ranges, 100 ma and 1
ampere. Each range may be programmed in 10% increments from 10%
to 110% of range.
iMULTI-STROBE ISOLATED
LOGIC
(Field Installable)
Permits any of the Fluke 4200 series Programmable Voltage Sources to
be remotely controlled by alarge variety of program sources such as a
computer, asystem coupler, as well as aFluke Automatic Test Equip-
metn System. Refer to Section 6for details.
1-6. SPECIFICATIONS
OUTPUT VOLTAGE 0to ±16.383 vdc
0to ±65.532 vdc
(Maximum output terminal voltage =±66v minimum)
OUTPUT VOLTAGE RESOLUTION . .
I6v Range
65v Range
1-2
1.0 mv
4mv
(Provisions have been made to allow changing of the MSB
weight to 8000 and 32000 mv by installation of ajumper
in the Preamplifier,)
2/75

OUTPUT CURRENT
CURRENT SINK CAPABILITY .
ACCURACY (1 5°C to 35°C, 90 days)
16v Range
65 vRange
STEADY STATE RIPPLE AND NOISE (10 Hz to 10 MHz
bandwidth) I6v Range
65 vRange
OUTPUT IMPEDANCE
EXTERNAL REFERENCE (Option -03)
Voltage Range
Input Impedance
Output Voltage
16v Range
65vRange
Output Current
Frequency Range
Accuracy (15°C to 35°C, 90 days with respect to
the External Reference, Ex r) 16vRange .
65 vRange .
Programming Resolution (Least significant bit)
16v Range
65 vRange
PROGRAMMABLE CURRENT LIMIT (Option -06)
100 ma Range
1amp Range
Minimum program possible
SPEED
OUTPUT STABILITY (Constant load, line and temperature)
16v Range, 24 hours
90 days
65vRange, 24 hours
90 days
TEMPERATURE COEFFICIENT (35°C to 15°C)
16v Range
65v Range
LOAD REGULATION
LOAD RECOVERY
4265A
0toil ampere
(Short circuit protected at LI ampere)
[sink (ma) =1000 —10 Eout (Overload protected)
The Current Limit Flag is energized when acurrent sink
overload condition occurs.
±(0.01% of program +100 uV)
±(0.01% of program +300 uV)
500 uV rms 7mV pp
1mV rms 7mV p-p
0.02 milliohms @dc; 1ohm @30 kHz
0to ±14.5 VDC or peak ac
100k ohms in parallel with 70 pf
0to 12v rms, 17V peak
0to 46vrms, 66V peak
707 ma rms, 1.0 amp peak
dc to 30 kHz
±(0.01% of program +.0001%(||^) +100 uV) at dc.
±(0.01% of program +.0001%(^-^-) +300 uV) at dc.
Exr x10"4volts
Exr x4x10"* volts
±10 mA to +110 mA in 10 mA increments
±100 mA to +1.1 amp in 100 mA increments
±10 mA
Settles to 0.01% of the programmed change in 100 fsec. A
range change does not increase settling time.
±(10 ppm of program +40 uv)
±(30 ppm of program +70 uv)
±(10 ppm of program +120 uv)
±(30 ppm of program +210 uv)
±(10 ppm of program +15 uv) per °C
±(10 ppm of program +15 uV) per &C
An output current change of 1ampere causes the output
voltage to change less than 0.001% of range.
The output voltage will settle to within 0.01% of final value
in 100 f£t cafter an output current change of 1amp.
2/75 1-3

4265A
LINE REGULATION The output voltage will change less than 0*00 1U ot range
for a±10% change in line voltage.
OUTPUT TERMINALS HIGH, LOW, HIGH SENSE, LOW SENSE. CHASSIS,
GUARD. Terminals located on rear panel. Tlie GUARD
terminal can be floated up to 1000 volts above chassis
ground.
PROGRAM CONTROL CONNECTOR A50 pin connector on rear panel* Mating connector is Am-
(See Table 1-3) phenol, Blue Ribbon, Part No. 57-30500.
INPUT POWER 115/230 vac ±10%, 48—62 Hz single phase, 200 watts fully
loaded.
ENVIRONMENTAL
Temperature 0Cto 50 Coperating*, 40 Cto 75 Cstorage.
Relative Humidity 0to 80%
Shock 20g, 1 1 millisecond half-sine wave
Vibration 4.5g, 10—55 Hz
Altitude 0to 10,000 ft -Operating 50,000 ft -Non-operating
SIZE (See Figure 1-1) 5-1/4” high x17” wide x19-7/8” (max) deep
ACCESSORIES
Manual Control Unit Allows manual checkout, calibration, and control. FLUKE
Model A4200.
Rack Mounting Brackets M05-205-600
Chassis Slides MO0-260-610 (18 )
MOO-280-610 (24”)
Mating Connector Amphenol, Blue Ribbon 57-30500, FLUKE PART NO.
266056.
Extender Card FLUKE PART NO. 292623
Figure 1-1. OUTLINE DRAWING

4265A
Table 1-2. PROGRAMMING INPUT/OUTPUTS
PROGRAM CONTROL All program control and response lines are compatible with DTL and TTL logic.
Programming lines are brought out on the rear panel.
LOGIC LEVELS Logic "1" ~0±.4 vdc or contact Logic "0" =+2 to +5 vdc or open
closure circuit
SIGN Connector Pin 35 Logic "1" =Negative output voltages
MAGNITUDE
DATA STROBE
Bit Conn. Bit Conn.
Wt. Pin Wt. Pin
2J3 12«8
2* 222s9
2l137* 10
o42311
2952112
2b62' 13
2772° 14
Two scomplement binary coding for negative values is used with the Isolated Con-
trol Logic Option -QL Sign and magnitude binary coding is used with the direct
coupled control logic Option -04.
Connector pin 33. When using the Isolated Control Logic, astrobe pulse is required
to start the digital-to-anaiog conversion process after avalid command is present.
Minimum pulse width is 500 nanoseconds. Anegative leading slope (+5V to OV
transition) is required. Upon release of the Data Strobe, the output will go to the
programmed value. If the Data Strobe is not used in the Direct Coupled mode, the
output will follow any command data perturbations. Logic "1" ="hold" condition.
RANGE
EXTERNAL REFERENCE
Connector Pin 29; Logic "0" “Low Voltage Range, Logic "1" =High Voltage
Range,
Connector Pin 36; Logic "0" =Internal DC Reference, Logic "1" -External Refer-
STANDBV
CURRENT LIMIT
RESPONSE SIGNALS
CURRENT LIMIT FLAG
READY/NOT READY FLAG
POWER CONNECTIONS
LOGIC GROUND
Connector Pin 34; Logic "0" =Operate Mode, Logic "1" =Standby; Output is
approximately 1% of programmed level.
Connector Pin Function Logic "1" Logic "0"
42 Range 1Amp 100 mA
43 Magnitude 80% of Range 0All "0"rs-
44 Magnitude 40% of Range 010% of range
45 Magnitude 20% of Range 0
46 Maanitude 10% of Range 0
Connector Pin 49; Logic "1" represents acurrent overload condition.
Connector Pin 37; Logic "0" ="Ready" condition; the output is within 0,01% of
the programmed increment for aresistive load.
Logic "1" -"Not Ready" condition; the power source is in the
process of settling to the programmed value.
Connector Pin 25; An internal, isolated power supply furnished +5 vdc, current
limited by 2.7 ohms, for use by the external system interface
logic.
Connector Pins It is recommended that alarge ground strap be used between
17 thru 24; the interface logic and the power source to reduce the digital pro-
gramming noise on the system ground.
2/75 1-5/1-6

4265A
List of Illustrations
FIGURE TITLE PAGE
MOutline Drawing 1-5
2-1 115/230 VAC Power Conversion 2-2
2-2 Accessory Rack Mounting Kits 2-2
2-3 Operating Features (Sheet 1of 2) 2-2
(Sheet 2of 2) 2-3
24 Remote Sensing Connections 24
2-5 Guarded Load Connection 2-5
2-6 Isolated Control Logic Timing (-01 Option) 2-7
2-7 Direct Control T'gic Timing (-04 Option) 2-8
2-8 Accuracy Versus External Reference Frequency 2-9
2-9 AC External Reference Feedthrough Versus Frequency (OV Output) ... 2-10
2-10 AC External Reference Phase Shift Versus Frequency 2-10
2-
11 AC External Reference Harmonic Distortion Versus Frequency 2-10
3-
1Power Source Equivalent Circuit 2-1
3-2 Model 4265A Block Diagram 2-2
3-3 Binary Ladder (Simplified) 3-6
34 Ladder Driver (Simplified) 3-6
3-5 Isolated Control Logic (Simplified) 3-7
3-6 Isolated Control Logic Timing 3-9
(continued on page iv)
2/75 iii

4265A
LIST OF ILLUSTRATIONS, continued
FIGURE TITLE PAGE
4-
1Assembly ,Adjustment, and Test Point Locations
5-
1Model 4265 ABinary Programmable Power Source
5-2 Mother PCB Assembly
5-3 Power Supply PCB Assembly
54 Model 4265 APre-Amplifier PCB Assembly
5-5 External Reference PCB Assembly (-03 External Reference Option)
5-6 Binary Ladder PCB Assembly
5-7 Isolated Control Logic PCB Assembly (-0 1Option)
5-8 Direct Coupled Control Logic (—04 Option)
5-9 Binary Display PCB Assembly (-02 Front Panel Display Option) .
5-10 No Display PCB Assembly (—05 Option)
S-l 1Current Limit PCB Assembly (-06 Option)
5-
12 Power Amplifier PCB Assembly (Sheet 1of 2)
(Sheet 2of 2)
ACCESSORY MODEL A4200
6-
1Model A4200 Manual Control Unit and Power Source ....
6*2 Controls, Indicators and Connectors
ACCESSORY RACK MOUNTING FIXTURES
6-1 Accessory Rack Mounting Kits
6-2 Rack Mounting Bracket Installation
6*3 Dual Rack Mounting
64 Chassis Slide Installation
ACCESSORY PROGRAMMING CONNECTOR
6-1 Programming Mating Connector
ACCESSORY EXTENDER CARD
6-1 Accessory Extender Card
6-2 Extender Card Installation
4-
3
5-
5
5-6
5-8
5-12
5-16
5-19
5-22
5-27
5-28
5-29
5-31
5-36
5-37
6-1
6-2
6-1
6-2
6-2
6-3
6-1
6-1
6-2
IV

List of Tables
TABLE TITLE PAGE
1-
1Options 1-2
1*2 Programming Input/Outputs 14
2-
1Programming Input/Outputs 2-6
2-
2Binary and Two’s Complement Coding (16V Range) 2-6
3-
1Operating Voltages 3-3
4-
1Recommended Test Equipment 4-1
4-2 Binary and Two’s Complement Coding 4-3
4-3 Linearity Checks 4-6
v/vi

4265A
Section 2
Operating Instructions
2-1. INTRODUCTION
2-2. This section contains information regarding instal-
lation and operation of the Model 4265A. It is recom-
mended that the contents of this section be thoroughly
read and understood before any attempt is made to operate
this power source. Should any difficulties be encountered
during operation, please contact your nearest John Fluke
Sales Representative or the John Fluke Mfg. Co., Inc,,
P.O. Box 7428, Seattle, Washington 98133, telephone (206)
774-221 1. Alist of Sales Representatives is located at the
rear of this manual.
2-3. SHIPPING INFORMATION
24. The Model 4265A was packaged and shipped in a
foam packed cardboard carton. Upon receipt, athorough
inspection should be performed to reveal any damage in
transient. Special instructions for inspection and claims are
included in the carton.
2-5. If reshipment of this power source is necessary,
the original container should be used. If the original con-
tainer is not available, anew one can be obtained from the
John Fluke Mfg. Co., Inc. Please reference the Model num-
ber when requesting anew shipping container.
2-6. INPUT POWER
2-7. This power source can be operated from either a
115 or 230 vac, 48 to 62 Hz, power line. Adecal on the
rear panel indicates which power line input is required. If it
becomes necessary to change from one power line voltage
to the other, proceed as follows:
a. Disconnect the power cord from the rear panel of
the power source.
b. Remove the top dust cover and inner cover.
c. Locate the Power Supply Assembly and 115/230
slide switch shown in Figure 2-L
d. Set the slide switch to the desired line voltage posi-
tion. Positions are labeled on the printed circuit
board.
e. Replace the inner cover and top dust cover.
f. Install the following rated value fuse in the rear
panel fuse holder.
115 VAC 230 VAC
2A, AGC 1A.AGC
g. Reconnect the power cord at the rear panel and
then energize the power source with the toggle
switch on the rear panel. The POWER lamp on the
front panel should illuminate.
2-8. RACK INSTALLATION
2-9. The power source is designed for bench-top use or
for installation in a19 inch equipment rack using the Ac-
cessory Rack Mounting Kit shown in Figure 2-2. Accessory
chassis slides can also be installed to better facilitate rack in-
stallation. Information regarding installation of these Ac-
2-1

4265A
Figure 2-1. 115/230 VAC POWER CONVERSION Figure 2-2. ACCESSORY RACK MOUNTING KITS

4265A
BARRIER STRIP
Contains the analog Input/
output terminals.
±SENSE TERMINALS
Provide four terminal load
connection. See para 2-18.
POWER SWITCH
Toggle switch used to energha the
power source. APOWER lamp on
the front panel Illuminates when
the power source Is energized.
PROGRAMMING CONNECTOR
Contefni the digital Input/output
connections required for program-
ming. An Accessory mating con-
nector la available.
POWER CONNECTOR
Provides connection
through the power cord
to line power.
FUSE
Protects the ec Input circuitry,
115 VAC 2A, AGC
230 VAC 1A, AGC
AIR FILTER
EXT REF (-03 Option)
Receives a0to ±14.5 vdc
or peak ac signal having a
frequency from dc to 30 kHz.
Input resistance la 100k. See
para 2-42.
±OUTPUT TERMINALS
Provide connection to the
loed. See pare 2-16.
GUARD TERMINAL
Provides for load connections
that reduce errors caused by
common mode signals. See
para 2-22.
CHASSIS TERMINAL
Provides connection to chassis
and earth ground See para 2-20.
Figure 2-3. OPERATING FEATURES (Sheet 2of 2)
cessories is given in the Section 6, Rack Installation sub-
section.
2-10. OPERATING FEATURES
2-11. The location and function of all connectors and
indicators is given in Figure 2-3.
2-12. OPERATING NOTES
2-13. The following paragraphs describe various condi-
tions which should be considered before operating the
Model 4265A.
2-14. AC Line Connection
2-15. The input power cord plug is athree prong, polar-
ized connection. This plug allows connection to either a
115 or 230 vac, 48 to 62 Hz, power line (see Input Power,
paragraph 2-6), while at the same time connects the power
source chassis to earth ground. Always ensure that the
round pin is connected to ahigh quality earth ground.
The power source is energized through atoggle switch on
the rear panel.
2-16. Load Connections
2-17. An eight terminal barrier strip, located on the rear
panel, serves as an analog input/output connector for the
power source. The ±power output terminals (OUTPUT HI
and LO) provide connection to the load. The ±sense ter-
2-3

4265A
mmols (SENSE HI and LO) are provided to allow remote
sensing at the load. The sense terminals are bussed through
jumpers installed at the factory to the output terminals. If
remote sensing is not required, the load is connected to the
respective ±output terminals and the sensing busses are not
removed. If remote sensing is required, the busses must be
removed and separate sense lines provided between the
sense terminals and the load. In either case, NEVER
operate the power source with the sense terminals discon-
nected. The CHASSIS terminal is connected directly to
the chassis and allows grounding of the load through the
input power cord, if desired. The GUARD terminals allows
load connections that can greatly reduce errors caused by
common mode signals. This guard connection should al-
ways be used if optimum noise free performance is to be
achieved.
2-18. Remote Sensing
2-19. When aload is connected to the OUTPUT ter-
minals, the t-R drop across the output power leads may be
excessive in some applications. If the rated accuracy of the
power supply is required at the load, remote sensing must
be used. For this reason, SENSE terminals are provided to
allow the power supply output to be sensed directly at the
load, thus compensating for any I-R drop in the output
power leads. Figure 24 shows an example of remote sen-
sing load connections.
NOTE!
The two jumpers on the barrier strip which bus
±sense to ±output must be removed for re-
mote sensing. When remote sensingfalways use
atwisted pair of insulated wire from the output
and sense terminals to the load Amaximum of
0.35 volts (at 25°
C
tdecreasing 0.002 volts per
degree Cat higjher temperatures) is allowable
between either OUTPUT terminal and its cor-
responding SENSE terminal The leads between
the OUTPUT and SENSE terminals and the
load must be large enough to carry the load
current of up to 1ampere and the sense cur-
rent of 1ma without exceeding this voltage.
2-20. Ground Connections
2-21. ACHASSIS terminal is provided at the rear panel.
This terminal is directly connected to the chassis of the
power source and earth ground through the round pin on
the input power plug, tf grounding of the load is desired,
this terminal provides aconvenient connection to earth
ground. When aguarded output (explained in paragraph
2-22) is not desired, this terminal should be connected to
the GUARD terminal.
Figure 24. REMOTE SENSING CONNECTIONS
2-22. Guard Connections
2-23. The power source is equipped with aguard shield
that isolates its internal circuitry from the chassis and
ground. AGUARD terminal at the rear panel is connected
to this shield and allows load connections that greatly re-
duce errors caused by common mode signals. The guard
may be driven to amaximum of 1000 volts above chassis
ground. Figure 2-5 shows asimplified diagram of aguarded
load connection.
2-24. PROGRAMMING INFORMATION
2-25. Digital control of all functions except POWER ON
is accomplished through a50 pin Amphenol, Blue Ribbon
connector on the rear panel. The power source is energized
through atoggle switch on the rear panel. Interface be-
tween the programming equipment and the power source
requires an Amphenol, Blue Ribbon 57-30500 mating con-
nector. This mating connector is available as an accessory
for the power source. It can be obtained from FLUKE
under PART NO. 266056. Installation information reguard-
ing this connector is located in Section 6.Table 2-1 lists
and describes each terminal on the Programming Connector.
2-26. Programming input requirements are compatible
with either DTL or TTL logic levels. Logic “O’1is +2.0 to
5.0 vdc or open circuit to logic ground. Logic “1” is
+0.4 vdc or short circuit to logic ground. Logic ground is
24