OPERATING &
PROGRAMMING GUIDE
HP Model E4356A
Telecommunications
DC Power Supply
HP Part No. 5964-8166
Microfiche No. 5964-8167
Printed in USA: August 1999
CERTIFICATION
Hewlett-Packard Company certifies that this product met its published specifications at time of shipment from the factory.
Hewlett-Packard further certifies that its calibration measurements are traceable to the United States National Bureau of
Standards, to the extent allowed by the Bureau’s calibration facility, and to the calibration facilities of other International
Standards Organization members.
WARRANTY
This Hewlett-Packard hardware product is warranted against defects in material and workmanship for a period of three years
from date of delivery. HP software and firmware products, which are designated by HP for use with a hardware product and
when properly installed on that hardware product, are warranted not to fail to execute their programming instructions due to
defects in material and workmanship for a period of 90 days from date of delivery. During the warranty period HewlettPackard Company will, at its option, either repair or replace products which prove to be defective. HP does not warrant that
the operation of the software, firmware, or hardware shall be uninterrupted or error free.
For warranty service, with the exception of warranty options, this product must be returned to a service facility designated
by HP. Customer shall prepay shipping charges by (and shall pay all duty and taxes) for products returned to HP for
warranty service. Except for products returned to Customer from another country, HP shall pay for return of products to
Customer.
Warranty services outside the country of initial purchase are included in HP’s product price, only if Customer pays HP
international prices (defined as destination local currency price, or U.S. or Geneva Expor t price).
If HP is unable, within a reasonable time to repair or replace any product to condition as warranted, the Customer shall be
entitled to a refund of the purchase price upon return of the product to HP.
LIMITATION OF WARRANTY
The foregoing warranty shall not apply to defects resulting from improper or inadequate maintenance by the Customer,
Customer-supplied software or interfacing, unauthorized modification or misuse, operation outside of the environmental
specifications for the product, or improper site preparation and maintenance. NO OTHER WARRANTY IS EXPRESSED
OR IMPLIED. HP SPECIFICALLY DISCLAIMS THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
FITNESS FOR A PARTICULAR PURPOSE.
EXCLUSIVE REMEDIES
THE REMEDIES PROVIDED HEREIN ARE THE CUSTOMER’S SOLE AND EXCLUSIVE REMEDIES. HP SHALL
NOT BE LIABLE FOR ANY DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES,
WHETHER BASED ON CONTRACT, TORT, OR ANY OTHER LEGAL THEORY.
ASSISTANCE
The above statements apply only to the standard product warranty. Warranty options, extended support contracts, product
maintenance agreements and customer assistance agreements are also available. Contact your nearest Hewlett-Packard
Sales and Service office for further information on HP’s full line of Support Programs.
2
Safety Summary
The following general safety precautions must be observed during all phases of operation, service, and repair of this
instrument. Failure to comply with these precautions or with specific warnings elsewhere in this manual violates safety
standards of design, manufacture, and intended use of the instrument. Hewlett-Packard Company assumes no liability for
the customer’s failure to comply with these requirements.
GENERAL.
This product is a Safety Class 1 instrument (provided with a protective earth terminal).
Any LEDs used in this product are Class 1 LEDs as per IEC 825-l.
ENVIRONMENTAL CONDITIONS
With the exceptions noted, all instruments are intended for indoor use in an installation category II, pollution degree 2 environment.
They are designed to operate at a maximum relative humidity of 95% and at altitudes of up to 2000 meters. Refer to the specifications
tables for the ac mains voltage requi rements and ambient operating temperature range.
BEFORE APPLYING POWER.
Verify that the product is set to match the available line voltage and the correct fuse is installed.
GROUND THE INSTRUMENT.
To minimize shock hazard, the inst rument chassis and cabinet must be connected to an electrical ground. The instrument must be
connected to the ac power supply mains through a three-conductor power cable, with the third wire firmly connected to an electrical
ground (safety ground) at the power outlet. For instruments designed to be hard-wired to the ac power lines (supply mains), connect the
protective earth terminal to a protective conductor before any other connection is made. Any interruption of the protective (grounding)
conductor or disconnection of the protective earth terminal will cause a potential shock hazard that could result in personal injury. If the
instrument is to be energized via an external autotransformer for voltage reduction, b e cert ai n that the autotransformer common terminal
is connected to the neutral (earthed pole) of the ac power lines (supply mains).
FUSES.
Only fuses with the required rated current, voltage, and specified type (normal blow, time delay, etc.) should be used. Do not use repaired
fuses or short circuited fuseholders. To do so co uld cause a shock or fire hazard .
DO NOT OPERATE IN AN EXPLOSIVE ATMOSPHERE.
Do not operate the instrument in the presence of flammable gases or fumes.
KEEP AWAY FROM LIVE CIRCUITS.
Operating personnel must not remove instrument covers. Component replacement and internal adjustments must be made by qualified
service personnel. Do not replace components with power cable connected. Under certain conditions, dangerous voltages may exist even
with the power cable removed. To avoid injuries, al ways disco nnect power, discharge circuits and remove external voltage sources before
touching components.
DO NOT SERVICE OR ADJUST ALONE.
Do not attempt internal service or adjustment unless another person, capable of rendering first aid and resuscitation, is present.
DO NOT EXCEED INPUT RATINGS.
This instrument may be equipped with a line filter to reduce electromagnetic interference and must be connected to a properly grounded
receptacle to minimize electric shock hazard. Operation at line voltages or frequencies in excess of those stated on the data plate may
cause leakage currents in excess of 5 .0 mA peak.
DO NOT SUBSTITUTE PARTS OR MODIFY INSTRUMENT.
Because of the danger of introducing additional hazards, do not install su bstitute parts or perform any unauthorized modification to the
instrument. Return th e i nstrument to a Hewlett-Packard Sales and Service Office for service and repair to ensure that safety features are
maintained.
Instruments which appear damaged or defective should be made inoperative and secured against unintended operation until they can be
repaired by qualified service personnel.
3
Safety Symbol - Definitions
Symbol Description Symbol Description
Direct current Terminal for Line conductor on permanently
installed equipment
Alternating current Caution, risk of electric shock
Both direct and alternating current Caution, hot surface
Three-phase alternating current Caution (refer to accompanying documents)
Earth (ground) terminal In position of a bi-stable push control
Protective earth (ground) terminal Out position of a bi-stable push control
Frame or chassis terminal On (unit)
Terminal for Neutral conductor on
Off (unit)
permanently installed equipment
Terminal is at earth potential
(Used for measurement and control
circuits designed to be operated
with one terminal at earth
potential.)
Standby (unit)
Units with this symbol are not completely
disconnected from ac mains when this switch is
off. To completely disconnect the unit from ac
mains, either disconnect the power cord or have
a qualified electrician install an external switch.
The WARNING sign denotes a hazard.
It calls attention to a procedure,
practice, or the like, which, if not
correctly performed or adhered to,
could result in personal injury. Do not
proceed beyond a WARNING sign
until the indicated conditions are fully
understood and met.
The CAUTION sign denotes a hazard. It calls
attention to an operating procedure, or the like,
which, if not correctly performed or adhered to, could
result in damage to or destruction of part or all of the
product. Do not proceed beyond a CAUTION sign
until the indicated conditions are fully understood
and met.
Acoustic Noise Information
Herstellerbescheinigung
Diese Information steht im Zusammenhang mit den Anfor derungen der Ma schinenläminformationsverordnung vom 18
Januar 1991.
* Schalldruckpegel Lp <70 dB(A) * Am Arbeitsplatz * Normaler Betrieb * Nach EN 27779 (Typprufung).
Manufacturer’s Declaration
This statement is provided to comply with the requirements of the German Sound Emission Directive, from 18 January
1991.
* Sound Pressure Lp <70 dB(A) *At Operator Position * Normal Operation * According to EN 27779 (Type Test).
4
Declaration Page
Manufacturer’s Name: Hewlett-Packard Company
Manufacturer’s Address: 150 Green Pond Road
declares that the Product
Product Name: Telecommunications DC Power Supply
Model Number: HP E4356A
conforms to the following Product Specifications:
DECLARATION OF CONFORMITY
according to ISO/IEC Guide 22 and EN 45014
Rockaway, New Jersey 07866
U.S.A.
Safety: IEC 348:1978 / HD 401S1: 1981
EMC: CISPR 11:1990 / EN 55011:1991 - Group 1 Class B
Supplementary Information:
The product herewith complies with the requirements of the Low Voltage Directive
73/23/EEC and the EMC Directive 89/336/EEC and carries the CE-marking accordingly.
Note 1: The product family was introduced prior to 12/93.
New Jersey August 1999
Location Date Bruce Krueger / Quality Manager
European Contact: Your local Hewlett-Packard Sales and Service Office or Hewlett-Packard GmbH,
Department TRE, Herrenberger Strasse 130, D-71034 Boeblingen (FAX:+49-7031-14-3143)
1
IEC 801-2:1991 / EN 50082-1:1992 - 4 kV CD, 8 kV AD
IEC 801-3:1984 / EN 50082-1:1992 - 3 V / m
IEC 801-4:1988 / EN 50082-1:1992 - 0.5 kV Signal Lines
1 kV Power Lines
Printing History
The edition and current revision of this manual are indicated below. Reprints of this manual containing minor corrections
and updates may have the same printing date. Revised editions are identified by a new printing date. A revised edition
incorporates all new or corrected material since the previous printing date. Changes to the manual occurring between
revisions are covered by change sheets shipped with the manual. In some cases, the changes apply to specific instruments.
Instructions provided on the change sheet will indicate if a particular change applies only to certain instruments.
Copyright 1999 Hewlett-Packard Company Edition 1 - August, 1999
This document contains proprietary information protected by copyright. All rights are reserved. No part of this document
may be photocopied, reproduced, or translated into another language without the prior consent of Hewlett-Packard
Company. The information contained in this document is subject to change without notice.
5
Table of Contents
Safety Summary 3
Safety Symbol - Definitions 4
Acoustic Noise Information 4
Declaration Page 5
Printing History 5
Table of Contents 6
1 - GENERAL INFORMATION 13
Introduction 13
Safety Considerations 13
Options 14
Accessories 14
Operator Replaceable Parts List 14
Description 15
Front Panel Programming 15
Remote Programming 15
Analog Programming 15
Output Characteristic 16
Output Ranges 16
Downprogramming 16
2 - INSTALLATION 17
Inspection 17
Damage 17
Packaging Material 17
Items Supplied 17
Location and Temperature 18
Bench Operatio n 18
Rack Mounting 18
Temperature Performance 18
Input Power Source 18
Installing the Power Cord 18
HP VXIplug&play Power Products Instrument Drivers 20
Downloading and Installing the Driver 20
Accessing Online Help 20
3 - TURN-ON CHECKOUT 21
Introduction 21
Preliminary Checkout 21
Power-On Checkout 21
Using the Keypad 22
Shifted Keys 22
Backspace Key 22
Output Checkout 22
Checking the Voltage Function 22
Checking the Current Function 23
Checking The Save And Recall Functions 24
Determining The GPIB Address 24
In Case Of Trouble 24
Line Fuse 24
Error Messages 25
Selftest Errors 25
6
Power-On Error Messages 25
Checksum Errors. 26
Runtime Error Messages 26
4 - USER CONNECTIONS 27
Rear Panel Connections 27
Load Wire Selection 27
Analog Connector 27
Connecting the Power supply to the Loa d 28
Output Isolation 28
Capacitive Loads 28
Inductive Loads 29
Battery Charging 29
Local Voltage Sensing 30
Remote Voltage Sensing 30
Setting Up Remote Sense Operation 30
Connecting the Sense Leads 30
CV Regulation 30
Output Rating 30
Output Noise 30
OVP Considerations 31
Stability 31
Operating Configurations 31
Connecting One Power supply to a Single Load 31
Connecting One Power supply To Multiple Loads 32
Connecting Units in Auto-Parallel 32
Connecting Units in Series 33
External Voltage Control 34
Controller Connections 35
Stand-Alone Connections 35
Linked Connections 35
5 - FRONT PANEL OPERATION 37
Introduction 37
Getting Acquainted 37
Programming The Output 40
Establishing Initial Conditions 40
Programming Voltage 40
Programming Overvoltage Protection 40
Programming Current 41
Programming Overcurrent Protection 42
CV Mode vs. CC Mode 42
Unregulated Operation 42
Saving and Recalling Operating States 43
Turn-On Conditions 43
Setting The GPIB Address 43
Types of Power supply GPIB Addresses 43
Changing the Power supply GPIB Address 44
6 - REMOTE PROGRAMMING 45
Prerequisites for Remote Programming 45
External Documents 45
SCPI References 45
GPIB References 45
GPIB Capabilities of the Power supply 46
7
Introduction To SCPI 46
Conventions 46
Types of SCPI Commands 46
Traversing the Command Tree 47
Active Header Path 47
The Effect of Optional Headers 47
Moving Among Subsystems 48
Including Common Commands 48
SCPI Queries 48
Value Coupling 48
Types of SCPI Messages 49
Structure of a SCPI Message 49
SCPI Data Formats 51
Numerical Data 51
Boolean Data 51
Character Data 51
SCPI Command Completion 52
Programming Examples 52
Programming Voltage and Current 53
Programming Protection Circuits 53
Changing Outputs by Trigger 53
Saving and Recalling States 53
Writing to the Display 54
Programming Status 54
Detecting Events via SRO 54
Reading Specific Registers 54
Programming the Digital I/O Port 55
System Considerations 55
Setting the GPIB Address 55
Changing the Power supply GPIB Address 55
Assigning the GPIB Address In Programs 56
DOS Drivers 57
Types of Drivers 57
Error Handling 57
HP BASIC Controllers 57
Sample Program Code 57
SCPI Confirmed Commands
1
62
NON-SCPI Commands 62
7 - LANGUAGE DICTIONARY 63
Introduction 63
Parameters 63
Related Commands 63
Order of Presentation 63
Common Comma nds 63
Subsystem Commands 63
Description Of Common Commands 64
*CLS 64
*ESE 65
*ESR? 65
*IDN? 66
*OPC 66
*OPC? 67
*OPT? 67
*RCL 68
*RST 69
8
*SAV 69
*SRE 70
*STB? 70
*TRG 71
*TST? 71
*WAI 71
Description Of Subsystem Commands 71
ABOR 72
Calibration Commands 72
Current Subsystem 73
CURR CURR:TRIG 73
CURR:PROT:STAT 73
Digital Subsystem 74
DIG:DATA 74
Display Subsystem 74
DISP 74
DISP:MODE 75
DISP:TEXT 75
Initiate Subsystem 76
INIT INIT:CONT 76
Measure Subsystem 76
MEAS:CURR? MEAS:VOLT? 76
Output Subsystem 77
OUTP 77
OUTP:PROT:CLE OUTP:PROT:DEL 77
OUTP:REL 78
OUTP:REL:POL 78
Status Subsystem 78
STAT:PRES 78
Status Operation Registers 79
STAT:OPER? 79
STAT:OPER:COND? 79
STAT:OPER:ENAB 79
STAT:OPER:NTR STAT:OPER:PTR 79
Status Questionable Registers 80
STAT:OUES? 80
STAT:QUES:COND? 80
STAT:QUES:ENAB 81
STAT:QUES:NTR STAT:QUES:PTR 81
System Commands 81
SYST:ERR? 82
SYST:LANG 82
SYST:VERS? 82
Trigger Subsystem 83
TRIG 83
TRIG:SOUR 83
Voltage Subsystem 83
VOLT VOLT:TRIG 83
VOLT:PROT 84
Command Summary 85
Programming Parameters 86
8 - STATUS REPORTING 87
Power supply Status Structure 87
Operation Status Group 87
Register Functions 87
9
Register Commands 87
Questionable Status Group 89
Register Functions 89
Register Commands 89
Standard Event Status Group 89
Register Functions 89
Register Commands 89
Status Byte Register 90
The MSS Bit 90
The RQS Bit 90
Output Queue 90
Service Request Enable Register 90
Inhibit/Fault Indicator 90
RI (Remote Inhibit) 90
DFI (Discrete Fault Indicator) 90
Initial Conditions At Power On 90
Status Registers 91
The PON (Power-On) Bit 91
Status Register Programming Examples 91
Determining the Cause of a Service Interrupt 91
Servicing an Operation Status Mode Event 91
Adding More Op eration Events 92
Servicing Questionable Status Events 92
Monitoring Both Phases of a Status Transition 92
A - SPECIFICATIONS 93
B - CALIBRATION 97
Introduction 97
Equipment Required 97
General Procedure 97
Parameters Calibrated 97
Test Setup 97
Front Panel Calibration 98
Entering the Calibration Values 98
Saving the Calibration Constants 98
Disabling the Calibration Mode 98
Changing the Calibration Password 98
Recovering From Calibration Problems 100
Calibration Error Messages 100
Calibration Over The GPIB 100
Calibration Example 100
Calibration Language Dictionary 101
CAL:CURR 101
CAL:CURR:LEV 101
CAL:PASS 101
CAL:SAVE 101
CAL:STAT 102
CAL:VOLT 102
CAL:VOLT:LEV 102
CAL:VOLT:PROT 102
HP BASIC Calibration Program 103
C - VERIFICATION 105
Introduction 105
10
Test Equipment Required 105
List of Equipment 105
Current Monitoring Resistor 105
Performing The Tests 106
General Measurement Techniques 106
Programming the Power supply 106
Order of Tests 106
Turn-on Checkout 106
Voltage Programming and Readback Accuracy 106
Current Programming and Readback Accuracy 107
D - ERROR MESSAGES 109
Power supply Hardware Error Messages 109
Calibration Error Messages 109
System Error Messages 109
E - LINE VOLTAGE CONVERSION 111
F - DIGITAL PORT FUNCTIONS 113
Digital Connector 113
Fault/Inhibit Operation 113
Changing The Port Configuration 115
Digital I/O Operation 116
Relay Link Operation 116
G - COMPATIBILITY LANGUAGE 119
Introduction 119
Parallel Polling 119
INDEX 123
11
General Information
Introduction
The following Getting Started Map will help you find the information you need to complete the specific task that you want
to accomplish. Refer to the table of contents or index of each guide for a complete list of the information contained within.
Table 1-1. Getting Started Map
Task Where to find information
General information
Capabilities and characteristics
Installing the unit
Location
Line connections
Checking out the unit
Verifying proper operation
Using the front panel
Making Connections
Load connections
Computer connections
Application Information
Using the front panel
Front panel keys
Front panel examples
Using the programming interface
GPIB interface
Programming the unit using SCPI (and COMPatibility) commands
SCPI commands
SCPI programming examples
SCPI language dictio nary
Installing the HP VXIplug&play instrument driver
Chapter 1
Chapter 2
Chapter 3
Chapter 4
Chapter 5
Chapter 6
Chapters 7 and 8 for SCPI commands.
Appendix G for COMPatibility commands
Chapter 2
1
NOTE: The driver must be installed on your pc to access the on-line
informa tio n. Drivers are available on the web at www.hp.co m/go /drivers.
Safety Considerations
This power supply is a Safety Class 1 instrument, which means it has a protective earth terminal. That terminal must be
connected to earth ground through a power source equipped with a 3-wire ground receptacle. Refer to the Safety Summary
page at the beginning of this guide for general safety information. Before installation or operation, check the po wer supply
and review this guide for safety warnings and instructions. Safety warnings for specific procedures are located at
appropriate places in the guide.
General Information 13
Options
Table 1-2. List of Options
Option Description
Standard
200
831
832
834
841
842
844
Input power 230 Vac, nominal
Input power 200 Vac, nominal
Power cord, 12 AWG, UL listed, CSA certified, without plug
Power cord, 4 mm
2
, harmonized, without plug
Power cord, 10 AWG, UL listed, CSA certified, without plug
Power cord, 12 AWG, UL listed, CSA certified, with NEMA 6-20P 20A/250V plug
Power cord, 4 mm
2
, harmonized, with IEC 309 32A/220V plug
Power cord, 10 AWG, UL listed, CSA certified, with NEMA L6-30P-30A/250V locking plug
908 Rack mount kit (HP 5062-3977) Support rails (E3663A) are required.
909 Rack mount kit with handles (HP 5062-3983) Support rails (E3663A) are required.
0BN
Service addendum with extra User’s Guide
Accessories
Table 1-3. List of Accessories
Description HP No. HP No.
GPIB cable (all models)
0.5 meters (1.6 ft) 10833D
1.0 meter (3.3 ft) 10833A
2.0 meters (6.6 ft) 10833B
4.0 meters ( 13 .2 ft) 10833C
Serial link cable 2.0 meters (6.6 ft) 5080-2148
Accessory slide mount kit 1494-0059
Operator Replaceable Parts List
Table 1-4. Operator Replaceable Parts List
Description HP Part No. Description HP Part No.
Cable assembly, GPIB
Cable assembly, serial link
Collar, rotary output control
Cover, ac input safety
Cover, dc output
Flatwasher, ac input safety cover
Foot, cabinet
Fuse, power 25A, 250V
(this is an internal fuse).
Knob, rotary output control
Lockwasher, ac input safety cover
Lockwasher, output bus bar, 1/4 spring
HP 59510/11A Relay Accessories
HP Series 667xA Service Manual
HP E4356A Service Addendum
Nut, output bus bar, hex 1/4-20x1/2
Nut, power ground, hex w/lw 3/8x32
Plug, analog connector (7-terminal)
Plug, digital connector (4-terminal)
(see Table 1-3)
(see Table 1-3)
5040-l700
5040- 1676
5040- 1674
3050-1053
5041-8801
2110-0849
0370-1091
2190-0484
3050-1690
5957-6382
5961-2583
5964-8170
2950-0084
0590-0305
1252-3698
1252-1488
Power cord assembly
Rack mount kit
Resistor, calibration
Screw, ac input safety cover
(M4.0 x 60 mm long)
Screw, carrying strap
(M5x0.8x10 mm)
Screw, output bus bar, 1/4-20x1/2
Screw, outer cover, (M5 x 0.8 mm)
Screw, output sense terminal
(M3x0.5x8mm)
Slide mount kit
Standoff, GP IB
Terminal, crimp, ac power cord
L or N terminal
Gnd terminal
(see Table 1-2)
(see Table 1-2)
(Appendix B)
0515-0156
0515-1384
2940-0103
0515-0073
0515-0104
(see Table 1-3)
0380-0643
0362-0681
0362-0207
General Information 14
Description
The HP E4356A is a unipolar, GPIB programmable power supply, which is programmable locally from the front panel or
remotely via a rear-panel analog control port. Operational features include:
■ Constant voltage (CV) or constant current (CC) output over the rated output ra nge.
■ Built-in overvoltage (OV), overcurrent (OC), and overtemperature (OT) protection.
■ Automatic turn-on selftest.
■ Pushbutton nonvolatile storage and recall of up to 5 operating states.
■ Local or remote sensing of output voltage.
■ Auto-parallel operation for increased total current.
■ Series operation for increased total voltage.
■ Analog input for remote programming of voltage and current.
■ Voltage output for external monitoring of output current.
■ User calibration from the front panel.
Front Panel Programming
T he front panel has both rotary (RPG) and keypad controls for setting the output voltage and curr ent. The panel di splay
provides digital readouts of the output voltage and current. Other front panel controls pe rmit:
■ Enabling or disabling the output.
■ Setting the overvoltage protection (OVP) trip voltage.
■ Enabling or disabling the overcurrent protection (OCP) feature.
■ Saving and recalling operating states.
■ Setting the GPIB address.
■ Reading GPIB error message codes.
■ Calibrating the power supply, including changing the calibration protection password.
Remote Programming
The power supply may be remotely programmed via the GPIB bus and/or from an analog input port. GPIB programming is
with SCPI (Standard Commands for Programmable Instruments) commands that make the power supply programs
compatible with those of other GPIB instruments. (A software Compatibility mode also permits programming in the
command set of the HP 6030xA Autoranging Series.) In addition to control functions, SCPI programming permits writing to
the front panel LCD and complete calibration functions. Power supply status registers permit remote monitoring of the
following conditions:
■ Overvoltage, overcurrent, overtemperature, and unregulated states.
■ Operating mode (constant voltage or constant current) .
■ State of the RI (remote inhibit) input signal.
■ Power-on status (PON).
■ Status of the output queue (QYE).
■ Pending triggers (WTG).
■ GPIB interface programming errors (CME, DDE, and EXE).
■ Calibration state (enabled or disabled).
The status registers can be programmed to generate an output fault signal (FLT) upon the occurrence of one or more
selected status events.
Analog Programming
The power supply has an analog port for remote programming. The output voltage and/or current of the power supply may
be controlled by individual dc programming voltages applied to this port. The port also provides a monitor output that
supplies a dc voltage proportional to the output current.
General Information 15
Output Characteristic
The power supply can operate in either CV (constant voltage) or CC (constant current) over its output voltage and current
ratings (see Figure 1-l). Although the power supply can op erate in either mode, it is d esigned as a constant volta ge source.
This means that the unit turns on in constant voltage mode with the output voltage rising to its Vset value. There is no
command for constant current operation. The only way to turn the unit on in constant current mode is by placing a short
across the output and then enabling or turning the output on.
Note that the power supply cannot be programmed to operate in a specific mode. After initial turn-on, the operating mode of
the unit will be determined by the voltage setting (V
operating point 1 is defined by the load line cutting the ope rating locus in the constant-voltage region. This region defines
the CV mode. Operating point 2 is defined by the load line cutting the operating locus in the constant-current region. This
region defines the CC mode.
Appendix A lists the specifications and supplemental characteristics.
Vout
80V
70V
), the current setting (Is), and the load impedance (RL). In Figure 1-1,
s
RL1
Vs
RL2
Is
26A 30A
Iout
Figure 1-1. Output Characteristic Curve
Output Ranges
Figure 1-1 shows two output ranges: 80V, 26A and 70V, 30A. The step in the output characteristic indicates that the power
supply cannot simultaneously output 80V and 30A. No separate command is required to select a range, the power supply
automatically selects one of the operating ranges based on the last parameter (either voltage or current) that is programmed.
For example, if you program 80V and 30A, the power supply will select the 70V, 30A range based on the last parameter
that was programmed: 30A.
Downprogramming
The power supply can sink current for more rapid down programming in the CV mode. This is an uncharacterized currentsinking area that provides a limited downprogramming capability.
General Information 16
2
Installation
Inspection
Damage
When you receive your power supply, inspect it for any obvious damage that may have occurred during shipment. If there is
damage, notify the shipping carrier and the nearest HP Sales and Support Office immediately. Warranty information is
printed in the front of this guide.
Packaging Material
Until you have checked out the power supply save the shipping carton and packing materials in case the power supply has to
be returned to Hewlett-Packard. If you return the power supply for service, attach a tag identifying the model number and
the owner. Also include a brief description of the problem.
Items Supplied
In additio n to this manual, check that the following items in Table 2-1 are included with your power supply (see Table 1-6
for part numbers):
Table 2-1. Items Supplied
Power cord
Analog
connector
Digital
connector
Serial cable
Output
hardware
Guide change
page
Your power supply was shipped with a power cord appropriate for your location. The cord may or may
not be terminated in a power plug (see "Options" in Chapter 1). If the cord is not included, contact your
nearest HP Sales and Support Office (see end of this guide ) to obtain the correct cord. These models
also include a power input safety cover with strain relief connector. It is required to secure the power
cord to the power supply.
A 7-terminal analog plug (see Table 1-4) that connects to the back of the unit. Analog connections are
described in Chapter 4.
A 4-terminal digital plug (see Table 1 -4) that connects to the back of the unit. Digital connections are
described in "Appendix D - Digital Po rt Functions"
A 2-meter cable (see “Accessories” in Chapter 1) that connects to the control bus (next to the GPIB
connector). This cable is used to serially connect multiple power supplies as described under "Controller
Connections" in Chapter 4.
Output hardware (screws with nuts and lockwashers) for securing your load wires to the output bus bars
(see Table 1-4).
If applicable, change sheets may be included with this guide. If there are change sheets, make the
indicated corrections in this guide.
Installation 17
Location and Temperature
Bench Operation
The T able A-2 in Appendix A gives the dimensions of your power supply. The cabinet has plastic feet that are shaped to
ensure self-alignment when stacked with other HP System II cabinets. The feet may be removed for rack mounting. Your
power supply must be installed in a location that allows sufficient space at the sides and rear of the cabinet for adequate air
circulation. Minimum clearances are 1 inch (25 mm) along the sides. Do not block the fan exhaust at the rear of the unit.
Rack Mounting
The power supply can be mounted in a standard l9-inch rack panel or cabinet. Rack mounting kits are available as Option
908 or 909 (with handles). Installation instructions are included with each rack mounting kit.
This power supply requires instrument support rails for non-stationary installations. These are
Temperature Performance
A variable-speed fan cools the unit by drawing air through the sides and exhausting it out the bac k. Using HP rack mount or
slides will not impede the flow of air. The temperature performance is as follows:
The unit operates without loss of performance within the temperature range of 0 °C to 45 °C.
normally ordered with the cabinet and are not included with the rack mounting kits.
Input Power Source
Do not apply power to the power supply until directed to do so in Chapter 3.
Check the line label on the rear of your unit and verify that the voltage shown there
Note This product requires single-phase input voltage.
You can operate your unit from a nominal 200 V or a 230 V single-phase power source, or from the line-to-line voltage of a
208-volt, 3-phase source. The proper source is indicated on the rear
Ratings" in Table A-2 for the voltage and frequency range for each type of power source.
Note The power source must be a dedicated line with no other devices drawing current from it.
The line fuse is located inside the power supply. Table 1-4 identifies the replacement fuse. See "In Case of Trouble" in
Chapter 3 for instructions on fuse replacement.
Installing the Pow er Cord
corresponds to the nominal line voltage of your power source. If it does not, see Appendix E - "Line
Volta ge Conversion" for instructions on changing the po wer sup ply's line voltage configuration.
label ( , Figure 2-2). See "AC Input
Installation of the power cord must be done by a qualified electrician and in accordance with local
electrical codes.
Installation 18
The power cord supplied with power supply may or may not include a power plug (see "Options" in Chapter l) at one end of
the cord. Terminating connections and a ground lug are attached to the other end of the cord. See Figure 2-2 and proceed as
follows:
1. If they are not already in place, position the strain relief connector
on the power cord .
nut
2. Secure the ground wire
3. For single-phase operation, connect the neutral wire
terminal (this line is fused inside the unit).
4. For line-to-line operation from a three-phase source as shown in Figure 2-3, connect one phase to the N input terminal
and another phase to the L input terminal (this line is fused inside the unit).
Note The N terminal is not internally grounded.
5. P osition the safety cover over the power input terminals and tighten the cover screws
screws
.
to the chassis earth ground stud.
to the N input terminal and the line wire to the L input
), safety cover , rubber boot , and connector
and strain relief connector
Figure 2-2. Connecting Power Cord
Figure 2-3. Connection to a 3-Phase Line
Installation 19
HP VXI
plug&play
Power Products Instrument Drivers
HP VXIplug&play Power Products instrument drivers for Microsoft Windows 95 and Windows NT are now available on
the Web at http: //www.hp.com/go/drivers. These instrument drivers provi de a high-level programmin g interface to your
HP Power Products instrument. HP VXIplug&play instrument drivers are an alternative to programming your instrument
with SCPI command strings. Because the instrument driver’s function calls work together on top of the VISA I/O library,
a single instrument driver can be used with multiple application environments.
Supported Applications System Requirements
HP VEE
Microsoft Visual BASIC
Microsoft Visual C/C++
Borland C/C++
National Instruments LabVIEW
National Instruments LabWindows/CVI
The HP VXIplug&play Power Products instrument driver
complies with the following:
Microsoft Windows 95
Microsoft Windows NT 4.0
HP VISA revision F.01.02
National Instruments VISA 1.1
Downloading and Installing the Driver
NOTE: Before installing the HP VXIplug&play instrument driver, make sure that you have one of the supported
applications installed and running on your computer.
1. Access Hewlett- Packard’s Web site at http://www.hp.com/go/d rivers.
2. Select the instrument for which you need the driver.
3. Click on the driver, either Windows 95 or Windows NT, and download the executable file to your pc.
4. Locate the file that you downloaded from the Web. From the Start menu select Run <path>:\hpxxxx. exe - where
<path> is the directory path where the file is located, and hpxxxx is the instrument driver that you downloaded .
5. Follow the directions on the screen to install the software. The default installation selections will work in most
cases. The readme.txt file contains product updates or corrections that are not documented in the on-line help. If
you decide to install this file, use any text editor to open and read it.
6. To use the VXIplug&play instrument driver, follow the directions in the HP VXIplug&play online help under
“Introduction to Programming”.
When you have finished installing the software, the HP VXIplug&play instrument driver files will be at the following
location on your hard drive:
On Windows 95
computers, files are
On Windows NT
computers, files are
Accessing Online Help
A comprehensive online programming reference is provided with the driver. It describes how to get started using the
instrument driver with HP VEE, LabVIEW, and LabWindows. It includes complete descriptions of all function calls as
well as example programs in C/C++ and Visual BASIC.
To access the online help when you have chosen the default Vxipnp start folder, click on the Start button and select
Programs | Vxipnp | HPxxxx Help (32-bit).
- where hpxxxx is the instrument driver.
Installation 20
Turn-On Checkout
Introduction
Note This chapter provides a preliminary introduction to the power supply front panel. See Chapter 5 - "Front Panel"
for more details.
Successful tests in this chapter provide a high degree of confidence that the power supply is operating properly. For
verification tests, see Appendix C - "Operation Verification”. Complete performance tests are given in the service manual.
Do not apply ac power to the power supply until told to do so.
Preliminary Checkout
1. Make certain that the front pa nel switch is off.
2. Examine the Line Voltage Rating or Line And Fuse Rating label (see Chapter 2 - " Installation" )
Verify that the line voltage rating agrees with your power source. If it does not, see Appendix E - "Line Voltage
Conversion".
3. Check the sense wiring as follows:
Remove the output safety cover and examine the output sense terminals. They should be wired for local sensing as
follows:
1. The +LS sense terminal wired to the +S terminal of the analog connector.
2. The –LS sense terminal wired to the –S terminal of the analog connector.
3. If the power supply is not wired for local sensing, make the above connections, using small-capacity wire
(AWG #22 is sufficient).
4. Make sure that there is no load connected to the output terminals or bus bars.
3
Power-On Checkout
1. Connect the power cord to the power supply .
2. Turn the front panel power switch to ON (1).
3. The power supply undergoes a self-test when you turn it on. If the test is normal, the following sequence appears on
the LCD:
The GPIB address (factory default is 5).
This is then follo wed by PWR ON INIT for approximately 10 seconds.
4. The display then goes into the meter mode with the Dis annunciator on and all others off. “Meter mode” means that
the VOLTS digits indicate the output voltage and the AMPS digits indicate the output current. These values will be
at or near zero.
5. Verify that the power supply fan is on by placing your hand near the rear grill to feel the air flow. You may also be
able to hear the fan operating.
6. Press
Note If the power supply detects an error during self-test, the display will show an error message. Go to “In Case of
Trouble” at the end of this chapter.
once. The Dis annunciator will go off and the CV annunciator will go on .
Turn-On Checkout 21
Using the Keypad
Shifted Keys
Some of the front panel keys perform two functions, one labeled in black and the other in blue. You access the blue function
by first pressing the blue
to the key’s shifted (blue) function.
key, which is not labeled. When the Shift annunciator is on, you will know you have access
Backspace Key
The key is an erase key. If you make a mistake entering a number and have not yet entered it (have not pressed
), you can delete the number by pressing . You may delete as many numbers as you wish by repeatedly pressing
this key.
Output Checkout
Important W hen the power supply is turned on, it asserts the state stored in EEPROM memory location 0. For a new
unit, this is the factory default (*RST) state. The following procedures assume that the factory default
state is still in location 0 (Turn-On Conditions in Chapter 5 for details).
Checking the Voltage Function
The tests in Table 3-1 check the basic voltage functions with no load connected to the power supply. The VOLTS display
will show various readings. Ignore the AMPS display.
Table 3-1. Checking the Voltage Functions (Output Terminals Open)
Procedure Display Explanation
Output Terminals Open or Connected to a Voltmeter
If Dis is on, turn it off by pressing
Press key VOLT 0.000
Press
Press 40.00 Enter the voltage. Meter mode disp lays output voltage. During these
Press several times Voltage decreases several millivolts each time you press the key.*
Press the same
number of times
* The number of millivolts change is determined by the voltage programming resolution
Rotate Voltage control first
counterclockwise and then
clockwise
Press
Press Display shows default OVP (overvoltage protection) trip voltage for
VOLT 40 Program output to 40 volts.
Voltage increases several millivolts each time you press the key.*
of your power supply (see Appendix A -"Supplemental Characteristics").
Control operates similarly to
40.00 Program output to 40 volts.
Default voltage setting. CV a nnunciator should be o n. (If CC
annunicator is on, incr ease the current by pressing
more times until CC turns off and CV turns on.)
tests, there may be a small (relative to full output) AMPS reading that
will be ignored.
and keys. The control
is rate sensitive. Turning it more quickly causes a more rapid change
in voltage.
your unit (see Appendix A - "Supplemental Characteristics").
one or
Turn-On Checkout 22
Press
Press 0.000 OVP voltage entered is less than the output voltage. This causes the
Press OV - - - - - Shows that the power supply shuts down because the OVP circuit has
Press Return display to meter mode (optional step).
Press
Press Prot Clear
)*
(
OV 30 Program the OVP to 30 volts, which is less than the output voltage.
OVP circuit to trip. The output drops to zero, CV turns o ff, and Prot
turns on.
tripped.
0.000 Program the OVP to 45 volts, which is greater than the output voltage.
Note: You cannot clear an OVP trip until you have first removed the
cause of the condition.
40.00
* is the unlabeled blue key.
The OVP circuit is cleared, restoring the output. Prot turns off and
CV turns on.
Checking the Current Function
The tests in Table 3-2 check the basic current functions with a short connected across the power supply output. Do not
program maximum output currents unless the shorting wire is capable of handling the current (see "Supplemental
Characteristics" and Table 4-2). The AMPS display will show various readings. Ignore the VOLTS display.
Table 3-2. Checking the Current Functions (Output Terminals Shorted)
Procedure Display Explanation
Turn off the power supply and connect a #14 AWG or larger wire across the output (+) and (–) terminals. If you intend to
test at full-rated output current, use a wire or wires of sufficient size to carry the maximum current of the unit (see
"Supplemental Characteristics" in Chapter l and Table 4-2 in Chapter 4).
Turn o n the unit. Meter mode
Press
Press CURR 1.000
Press
Press several times
Press the same
number of times
*The number of milliamperes is determined by the current programming resolution of the
Rotate the Current control
counterclockwise and then
clockwise
Press
VOLT 80.00
1.000
power supply (see "Supplemental Characteristics" in Chapter 1).
Essentially zero output with Dis annunciator o n.
Program output to 80 volts.
Program output to 1 ampere.
Dis annunciator turns off, CC annunciator turns on, and AMPS
display shows the programmed current.
*Current decreases several milliamperes each time you press the key.
*Current increases several milliamperes each time you press the key.
Control operates similarly to the
control is rate sensitive. Turning it more quickly causes a more rapid
change in current.
You have enabled the overcurrent protection circuit. The circuit then
tripped because of the output short. The CC annunciator turns off and
the OCP and Prot annunciators come on. Output current is near z ero.
and keys. The
Turn-On Checkout 23
Press
Press
Dis annunciator turns on.
You have disabled the overcurrent protection circuit. The OCP
annunciator turns off.
Press
( )**
Press
You have cleared the overcurrent protection circuit. The Prot
annunciator turns off.
Dis turns off and CC turns on. The output current is restored.
If you have a shorting wire of sufficient capacity, you may continue testing up to the maximum rated current of the power
supply (see "Performance Specifications"). When finished, go to the next step.
Press
Dis turns on and output current drops to zero.
Turn off the power supply and remove the short from the output terminals.
Checking The Save And Recall Functions
HP E4356A power supplies have five nonvolatile memory storage locations (0 through 4). Proceed as follows:
■ Make certain that the output is on (Dis annunciator is off).
■ Set the voltage output to 5 by pressing .
■ Save this value to location 1 by pressing .
■ Return the output voltage to 0 by pressing (This step is based on the fact that a newly shipped power
supply has the *RST parameters stored in location 0 (see "Chapter 5 - Front Panel" for more information).
■ Press and notice that the output voltage returns to the value stored in location 1.
Determining The GPIB Address
When the power supply is turned on, the display shows ADDR n, where n is the power supply GPIB address. Any time you
want to see the address, press
.
The disp lay will indicate ADDR 5, which is the factory default. If the address has been changed, then a different number
will appear (see “Setting the GPIB Address” in “Chapter 5 - Front Panel”).
In Case Of Trouble
Line Fuse
If the p ower supply appears "dead" with a blank d i splay and the fan not running, first check your power source to b e certain
line voltage is being supplied to the power supply. If the power source is normal, the power supply line fuse may be
defective. If the unit has a defective fuse, replace it only once. If it fails again, investigate the reason for the failure. Proceed
as follows:
Hazardous voltage can remain inside the power supply even after it has been turned off. Fuse
replacement should be done only by qualified electronics personnel.
Turn-On Checkout 24
l. Turn o ff the front panel p ower switch and unplug the line cord from the power source.
2. Remove the power supply dustcover as follows:
3. Observe the inp ut rail LED under the RFI shield (see Figure E-3 in Appe ndix E). If the LED is on, there is still
4. Connect a dc voltmeter across test points TPl and TP2 (Figure E-3). It may be necessary to remove the RFI shield in
5. Replace the fuse with one of the same type (see Table 1-4 in Chapter l). Do not use a slow-blow type fuse.
6. If you removed it in step b, be sure to replace the RFI shield.
7. Replace the dust cover.
8. Connect the line cord to the power source.
9. Turn on the front panel power switch and check the operation.
The line fuse is located inside the power supply. To change it, proceed as follows:
a. Remove the four screws securing the carrying straps and dustcover.
b. Spread the bottom rear of the dustcover and pull it back to disengage it from the front panel.
c. Slide the dustcover back far enough to expose the line fuse (1).
hazardous voltage inside the unit. Wait until the LED goes out (this may take several minutes) before proceeding.
order to reach these test points. (The shield is secured by four screws on each side.) When the voltmeter indicates 60 volts
or less, it is safe to work inside the power supply.
Power Fuse ó Line Filter ì Rear of Power supply
Figure 3-1. Line Fuse Location
Error Messages
Power supply failure may occur during power-on selftest or during operation. In either case, the display may show an error
message that indicates the reason for the failure.
Selftest Errors
When a selftest error occurs, it prevents all front pa nel operation. The display may show either a power-on error message or
a checksum error message.
Power-On Error Messages
Power-on messages appear as:
En- - - - - -
Where "n" is a number listed in Table 3-3. If this occurs, turn the power off and then back on to see if the error persists. It is
possible to recover from the EE CHKSUM error (see "Checksum Errors"). If any other message persists, the power supply
requires service.
Turn-On Checkout 25
Table 3-3. Power-On Selftest Errors
Error
No.
El
E2
E3
E4
E5
E6
E7
Display Failed Test Error
FP RAM
FP ROM
EE
Front Panel RAM E8
Front Panel ROM checksum E9
EEPROM E10
CHKSUM
PRI XRAM
PRI IRAM
PRI ROM
HPIB
Primary external RAM Ell
Primary internal RAM
Primary ROM checksum E12
HP-IB R/W to serial poll
1
No.
Display Failed Test
SEC RAM
SEC ROM
SEC 5V
Secondary RAM
Secondary ROM checksum
Secondary 5 V ADC
reading
TEMP
DACS
Secondary ambient
thermistor reading
Secondary VDAC/IDAC
readback
1HP-IB = GPIB
Checksum Errors.
If the display shows EE CHKSUM, the power supply has detected an EEPROM checksum error. A checksum error can
occur due to the following conditions:
■ Excessive number of write cycles to an EEPROM (see "Nonvolatile Memory Write Cycles" in "Supplemental
Characteristics" tables). This condition, which would appear only after extended use, is not recoverable and requires
service.
■ Loss of ac input power during a checksum calculation. This condition, which is very unlikely, is recoverable.
You may be able to recover from a checksum error by writing to the EEPROM while the power supply is in the calibration
mode. To do this, proceed as follows:
1. Enable the calibration mode by pressing
2. PASWD will appear on the display.
3. Press the number keys corresponding to the password, followed by
Note On new equipment, the calibration password corresponds to the four-digit model number (such as ).
See "Appendix A - Calibration" for more information about the calibration password.
4. Save any operating state (for example, press
5. Turn the power off and then back on.
A normal display free of error messages should appear. If not, the power supply requires service.
.
. The Cal annunciator will go on.
).
Runtime Error Messages
Under unusual operating conditions, the VOLT or AMPS displ ay may show +OL or –OL. This indicates that the output
voltage or current is beyond the range of the meter readback circuit. Table 3-4 shows other error messages that may appear
at runtime.
Table 3-4. Runtime Errors
Display Meaning
EE WRITE ERR
SBUB FULL
SERIAL DOWN
STK OVERFLOW
EEPROM status timeout
Message too long for buffer
Failed communication with front
Front panel stack overflow
Turn-On Checkout 26
Display Meaning
UART FRAM ING
UART OVERRUN
UART PARITY
UART byte framing error
Overfilled UART receive buffer
UART byte parity error panel
4
User Connections
Rear Panel Connections
Make application load connections to the output terminals or bus bars, analog connector, and digital connector as shown on
the rear-panel drawing for your model power supply. Make controller connections (GPIB and serial link) as shown in Figure
4-6 at the end of this chapter.
Load Wire Selection
Fire Hazard To satisfy safety requirements, load wires must be large enough not to overheat when
Table 4-1 lists the characteristics of AWG (American Wire Gauge) copper wire.
AWG Ampacity
No.
14 25 0.0103 8 60 0.0025
12 30 0.0065 6 80 0.0016
10 40 0.0041 4 105 0.0010
1. Ampacity is based on 30 °C ambient temperature with conductor rated at 60 °C. For ambient temperature other
than 30 °C, multiply the above ampacities by the following constants:
21-25 1.08 41-45 0.71
26-30 1.00 46-50 0.58
31-35 0.91 51-55 0.41
36-40 0.82
2. Resistance is nominal at 75 °C wire temperature.
carrying the maximum short-circuit current of the power supply. If there is more than one load, then
any pair of load wires must be capable of safely carrying the full-rated current of the unit.
Table 4-1. Stranded Copper Wire Capacity and Resistance
l
Temp (°C) Constant
Resistance
(Ω/m)
2
AWG Ampacity
No.
NOTES:
Temp (°C) Constant
1
Resistance
(Ω/m)
2
Analog Connector
This connector, which is on the rear panel, is for connecting remote sense leads, external current monitors, and external
programming sources. The connector accepts wires sizes from AWG 22 to AWG 12.
Insert Wires
ó Ti ghten Screws
IM Current monitor output.
VP Voltage programming input.
+IP Differential current programming input.
–IP Differential current pro gramming input.
↓P Common for VP and IM signals (referenced to +OUT).
Figure 4-1. Rear Panel Analog Connector
+S + remote sense input.
–S –remote sense input.
User Connections 27
Note It is good engineering practice to twist and shield all signal wires to and from the analog and digital connectors
Digital Connector
This co nnector, which is on the rear panel, is for connecting fault/inhibit, digital I/O, or relay link signals. The connector
accepts wires sizes from AWG 22 to AWG 12.
Insert Wires
ó Ti ghten Screws
Pin No. Fault/Inhibit
1
2
3
4
NOTE: Factory default function is FAULT/INHIBIT.
FLT OUTPUT
FLT OUTPUT
INH INPUT
INH COMMON
Figure 4-2. Rear Panel Digital Connector
FUNCTION
1
Digital I/O
OUT 0
OUT 1
IN/OUT 2
COMMON
Relay Link
RLY SEND
NOT USED
RLY RT N
COMMON
2
Connecting the Power supply to the Load
Output Isolation
The output of the power supply is isolated from earth ground. Either output terminal may be grounded, or an external
voltage source may be conne cted between either output a nd ground. However, both output terminals must be kept within
± 240 Vdc of ground. An earth ground terminal is provided on the rear panel for convenience, such as grounding wire
shields.
T he earth ground terminal on the rear panel is a low-noise signal gr ound for convenience only. It is not
designed to function as a safety ground.
Capacitive Loads
In most cases, the power supply will continue to be stable with additional external load capacitors. However, large load
capacitors may cause ringing in the unit’s transient response. It is possible that certain combinations of load capacitance,
equivalent series resistance, and load lead inductance will result in instability. If you need help in solving a stability
problem, contact an HP service engineer through your local Sales and Support Office (see end of this guide).
If the power supply output is rapidly programmed into capacitive loads, the unit may momentarily cross into constant
current (CC) mode. This extends the CV programming time and limits the maximum slew rate to the programmed current
divided by the total internal and external capacitance. These momentary crossovers into CC mode will not damage the unit.
User Connections 28
Output Safety Cover ó Analog Connector ì– Output Bus Bar
ö – Local Sense Terminal ú + Local Sense Terminal ÷+ Output Bus Bar
ø Signal Common í Local Sense Jumpers û Rear Knockouts
ç Bo ttom Knockout
Insert screwdriver blade in slot and pry out Bend along joint and break off
WARNING
DO NOT LEAVE UNCOVERED HOLES IN OUTPUT COVER. IF TOO MANY
KNOCKOUTS HAVE BEEN REMOVED, INSTALL A NEW COVER.
Figure 4-3. Rear Panel Output Connections
Inductive Loads
Inductive loads provide no loop stability problems in CV mode. However, in CC mode inductive loads will form a parallel
resonance network with the power supply's output capacitor. Generally, this will not affect the stability of the unit, but it
may cause ringing of the current in the load. Ringing will not occur if the Q (quality factor) of the parallel resonant network
is ≤1.0. Use the following formula to determine the Q of your output.
14 m
L1
Ω
Q=
RCxtint eR+
where: C = model-dependent internal capacitance (see below); L = inductance of the load; Rext = equivalent series
resistance of the load; R
C=
= model-dependent internal resistance (see below):
int
R
7,000 µF
=
int
If the Q is greater than 0.5, inductive loads will ring with the output capacitance and will be damped according to the
following equation:
Battery Charging
The power supply's OVP circuit has a downprogrammer FET that discharges the power supply output whenever OVP trips.
If a battery (or other external voltage source) is connected across the output and the OVP is inadvertently triggered or the
output is programmed below the battery voltage, the power supply will sink current from the battery. To avoid this, insert a
reverse blocking diode in series with the ⊕ output of the unit. Connect the diode cathode to the + battery terminal and the
diode anode to the ⊕ output terminal of the unit. The diode may require a heat sink.
User Connections 29
Local Voltage Sensing
Your po wer supply was shipped set up for local sensing. This means that the unit will sense and regulate its output at the
output terminals, not at the load. Since local sensing does not compensate for voltage drops across screw terminals, bus
bars, or load leads, local sensing should only be used in applications that req uire low output current or where load regulation
is not critical.
Local sensing is obtained by connecting the +LS sense terminal to the +S analog connector pin and the pin and the –LS
sense terminal to the –S analog connector pin. The power supply is shipped with these connections made.
Note If the sense terminals are left unconnected, the voltage at the bus bars will increase approximately 3 to 5% over the
programmed value. Since it is measured at the sense terminals, the voltage readback will not reflect this increase.
Remote Voltage Sensing
The dashed lines in the wiring diagrams illustrate remote voltage sensing. The remote sense terminals of the power supply
are connected directly to the load rather than to the output terminals. This allows the unit to automatically compensate for
the voltage drop in the load leads as well as to accurately read back the voltage directly across the load.
Setting Up Remote Sense Operation
Remote sensing is obtained by removing the jumpers connecting the +LS sense terminal to the +S analog connector pin and
the –LS sense terminal to the –S analog connector pin. The power supply is shipped with these jumpers connected.
Connecting the Sense Leads
You must connect the positive side of the load to the +S analog connector pin and the negative side of the load to the –S
analog connector pin (see Figure 4-1). Connect the sense leads carefully so that they do not become open-circuited. If sense
leads are left open during operation, the unit will regulate at the output terminals instead of at the load. Remember to bundle
or tie wrap the load leads to minimize inductance and reduce noise pickup.
CV Regulation
The voltage load regulation specification in Table A-1 applies at the output terminals of the power supply. When remote
sensing, this specification must be compensated. Add an increment to the voltage load regulation specification as specified
by “∆mV” in the equation given unde r Load regulation in Table A-2.
Output Rating
The rated output voltage and current specification in Table A-1 applies at the output terminals of the power supply. With
remote sensing, any voltage dropped in the load leads causes the unit to increase the voltage at the output terminals so it can
maintain the proper voltage at the load. When you attempt to operate at the full-rated output at the load, this forces the
voltage at the output terminals to exceed the unit's rated output. This will not damage the unit, but may trip the OVP
(overvoltage protection) circuit, which senses the voltage at the output bus bars. When operated beyond its rated output, the
unit's performance specifications are not guara nteed, although typical pe rformance may be good. If the excessive demand on
the unit forces it to lose regulation, the Unr annunciator will indicate that the output is unregulated.
Output Noise
Any noise picked up on the sense leads also appears at the output of the power supply and may adversely affect the load
voltage regulation. Be sure to twist the sense leads to minimize external noise pickup and route them parallel and close to
the load leads. In noisy environments, it may be necessary to shield the sense leads. Ground the shield only at the power
supply. Do not use the shield as one of the sense conductors.
User Connections 30
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