B+K precision VSP6020 User manual

Models VSP6020, VSP2050, VSP4030 and VSP12010 High Power Switching DC Power Supplies
Instruction Manual

Section 1
Test Instrument Safety
WARNING
Normal use of test equipment exposes you to a certain amount of danger from electrical shock because testing
must sometimes be performed where exposed voltage is present. An electrical shock causing 10 milliamps of
current to pass through the heart will stop most human heartbeats. A Voltage as low as 35 volts dc or ac (rms.)
should be considered dangerous and hazardous since it can produce a lethal current under certain conditions.
Highervoltagesposeanevengreaterthreatbecausesuchvoltagecanmoreeasilyproducealethalcurrent.Your
normal work habits should include all accepted practices to prevent contact with exposed high voltage and to
steer current away from your heart in case of accidental contact with high voltage. You will significantly reduce
the risk factor if you know and observe the following safety precaution.
1. Don’t expose high voltage needlessly. Remove housings and covers only when necessary. Turn off equip-
ment while making test connections in high voltage circuits. Discharge high voltage capacitors after removing
power.
2. If possible, familiarize yourself with the equipment being tested and the location of its high voltage points.
However, remember that high voltage may appear at unexpected points in defective equipment.
3. Use an insulated floor material or a large, insulated floor to stand on and an insulated work surface on which
to place equipment and make certain such surfaces are not damp or wet.
4. Use the time proven “one hand in the pocket” technique while handling an instrument probe. Be particularly
careful to avoid contacting a nearby metal object that could provide a good ground return path.
5. When testing ac powered equipment, remember that ac line voltage is usually present on some power input
circuits such as the on-off switch, fuses, power transformer etc. any time the equipment is connected to an ac
outlet, even if the equipment is turned off.
6. Some equipment with a two-wire ac power cord, including some with polarized power plugs, is the “hot chas-
sis” type. This includes most recent television receivers and audio equipment. A plastic wooden cabinet
insulates the chassis to protect the customer. When the cabinet is removed for servicing, a serious shock
hazard exists if the chassis is touched. Not only does this present a dangerous shock hazard, but damage to
test equipment. Always connect an isolation transformer between the ac outlet and the equipment under test.
TheB&KPrecisionModelTR-110 or 1604AIsolationTransformeror Model 1653A or 1655AACPowerSupply
is suitable for most applications. To be on the safe side, treat all two-wire ac equipment as “hot chassis”
unless you are sure it is isolated chassis or an earth ground chassis.
7. On test instruments or any equipment with a 3-wire ac power plug, use only a 3-wire outlet. This is a safety
feature to keep the housing or other exposed elements at earth ground.
8. B&K Precision products are not authorized for use in any application involving direct contact between our
product and the human body or for use as a critical component in a life support device or system. Here “direct
contact” refers to any connection from or to our equipment via any cabling or switching means. A “critical
component” is any component of a life support device or system whose failure to perform can be reasonably
expected to cause failure of that device or system or to affect its safety or effectiveness.
Never work all alone. Someone should be nearby to render aid if necessary. Training in CPR (cardiopulmo-
nary resuscitation) first aid is highly recommended.

Section 2
1.1 INTRODUCTION
1.2 FEATURES
1.3 MARKINGS
1.4 INTERFACE
1.5 SPECIFICATION
ORDERING INFORMATION
1.1 INTRODUCTION
The VSP SERIES power supplies are designed to deliver power in constant
voltage and constant current mode by switch mode conversion in sleek 1U high
cabinet and in a 19’’ rack construction.
This series comprises the two device soft switching technology that yields
very high efficiency of conversion for dc-to-dc converter part. Also it comprises
power factor correction circuity, which shapes the input current to follow the voltage
to maintain almost unity power factor at full load, and limits the current harmonics
in the input line.
It provides the user the option of isolated analog voltage, current and resis-
tance programming with built-in isolation amplifiers. It gives the option to monitor
the isolated signals with the option to change either from 0 to 5 Volts or from 0 to
10 Volts, for output voltage and current from 0 to full-scale level. It provides the
display of the output voltage, over voltage set level and current with 3-digit LED
displays. Piggyback series pass device ensures the ripple and noise levels to very
low values. Current sharing facility in the module gives the advantage to increase
the power with ease and the vents in the front and the rear enables it with abso-
lutely zero stacking. The module can be switched on/off through the front panel
ON/OFF switch or remote switch on rear panel.
VSP series provides digital interface options for remote programming from
PC. The digital interface provides 12-bit resolution for control as well as monitoring
the output.

Some of the features of the power supply are listed below:
1.2 FEATURES
§MAINS OPERATED, WITH WIDE INPUT RANGE.
§POWER FACTOR CORRECTED INPUT.
§ISOLATED D.C. OUTPUT.
§1200-WATT OUTPUT POWER.
§CONSTANT VOLTAGE OPERATION FROM 0 TO FULL-SCALE LEVEL.
§CONSTANT CURRENT OPERATION FROM 0 TO FULL-SCALE LEVEL.
§OVER VOLTAGE CONTROL FACILITY.
§REMOTE SENSING FACILITY.
§PARALLELABLE CURRENT SHARING OUTPUT.
§HIGH OVERALL EFFICIENCY – 80% TYPICAL.
§VERY LOW OUTPUT RIPPLE AND NOISE.
§INPUT EMI FILTERING TO MEET EN55022 CLASS A.
§20 MILLISECOND HOLD-UP TIME.
§TWO FRONT PANEL DPMS. FOR V / O.V AND I.
§MULTI TURN POTENTIOMETERS FOR V, O.V AND I SET.
§FRONT PANEL OUTPUT TERMINALS FOR MONITORING.
§SLEEK, 1U HIGH, 19 INCH RACK CONSTRUCTION.
§INTERNAL FORCED AIR COOLING WITH ZERO STACKING.
§ISOLATED ANALOG VOLTAGE, CURRENT AND RESISTANCE PROGRAM
MING AND MONITORING.
§REMOTE ON/OFF FACILITY.
§RS232/ GPIB/ INTERFACE.
1.3 MARKINGS
The unit has the name PROGRAMMABLE PFC DC SUPPLY written clearly
on the top of the front panel. The Model Number and ratings are also clearly written
on the front panel. The ratings are clearly written on the rear panel, just near the
output terminals.
1.4 INTERFACE
The unit has both local as well as remote controls. For Remote operation, the
series offers analog as well as digital interface or both. Both RS 232 or GPIB digital
interfaces can be provided.

1.5 SPECIFICATIONS
Output Specification
Model VSP6020*VSP2050*VSP4030*VSP12010*
Power 1.2KW 1.2KW 1.2KW 1.2KW
Output Voltage 0–60V 0–20V 0–40V 0–120V
Output Current 0–20A 0–50A 0–30A 0–10A
Ripplerms.(10Hzto1MHz) <10mV <15mV <10mV <20mV
Noise(10Hzto 20MHz) <45mVpp <45mVpp <45mVpp <45mVpp
Programming Resolution (Digital Interface), LSB (not LED displays)
Voltage 20 mV 10 mV 10 mV 100 mV
Current 10 mA 20 mA 10 mA 10 mA
Output Programming Accuracy(Analog Programming 0 To 5v & 0 To 10)
Voltage 0.5 % of F. S. ± 1 Digit (spec. for all VSP models)
Current 0.5 % of F. S. ± 1 Digit (spec. for all VSP models)
Meter Accuracy
Voltage +/- 0.2% of F.S. +/- 3 Digit. (spec. for all VSP models)
Current +/- 0.2% of F.S. +/- 3 Digit. (spec. for all VSP models)
Regulation
CVLineRegulation(mV) 0.1 % of F.S (spec. for all VSP models)
CCLine Regulation(mV) 0.1 % of F.S (spec. for all VSP models)
CVLoad Regulation(mA) 0.1 % of F.S (spec. for all VSP models)
CCLoad Regulation (mA) 0.1 % of F.S (spec. for all VSP models)
Output Specification
Stability 0.05%
Efficiency<80%Minimum
TransientResponse 250 microseconds forload changefrom 40% to 90%
Mode Of Operation
Local Mode Through front panel potentiometer for voltage, current and
over voltage and Push switch for Output ON/ OFF control.
Remote Mode InterfaceAnalog programming of voltage
and current.
Voltage: 0 - 5 volts or 0 – 10 volts for output voltage and
current, selection through DIP-switch.
Resistance: 0 – 4.85k ohms from 0 to full-scale level.
*=Specification also apply to correspondingGPIB model
F.S= FullScale. Fullscale willbe differentfor eachmodel. Example:If you have a VSP2050
andyou aremeasuring thevoltage meteraccuracy,the metercan notoff more than0.3V (20V
+0.2% +3digit). Note:3 digitsrefferes to the power supply displays leastsignificant digit.

Digital Interface RS-232 / GPIB
Protections
Over voltage protection Programmable through POT in local mode and through
digital interface in remote mode.
Over temperature protection Through 90 °C. Thermal switch on heat sink.
Input specifications
Mains Input Range 95Vac to 264Vac.
Input Frequency 47 To 63 Hz
Input Power Factor 0.99 On Full Load At Nominal Input.
Inrush Current Limited By NTC
Operating Environment
Temperature 0 - 50°C
Relative Humidity < 80% rh – non condensing
Storage Temperature - 20°C. to + 70°C.
Warm-up Time 15 minutes.
Safety Standards
EMI Filtering EN55022 Class-A
Safety Class EN60950
Mechanical Specifications
Weight (appox.) 13.7lbs. (6.2 KG.)
Dimensions (WxHxD) 19 x 1.75 x 18” (483 x 44.5 x 457mm)
Dimensions with rubber feet 19 x 2.13 x 20” (483 x 54 x 457mm)

1.6 ORDERING INFORMATION:
MODEL NO DESCRIPTION
VSP6020 60V, 20A power supply with opto-isolated analog interface and RS-232
VSP6020GPIB 60V, 20A power supply with opto-isolated analog interface and GPIB
VSP4030 40V, 30A power supply with opto-isolated analog interfaceandRS-232
VSP4030GPIB 40V, 30A power supply with opto-isolated analog interface and GPIB
VSP2050 20V, 50A power supply with opto-isolated analog interface and RS-232
VSP2050GPIB 20V, 50A power supply with opto-isolated analog interface and GPIB
VSP12010 120V, 10A power supply with opto-isolated analog interface and RS-232
VSP12010GPIB120V, 10A power supply with opto-isolated analog interface and GPIB

Section 3
2.1 INTRODUCTION
2.2 UNPACKING
2.3 INPUT POWER REQUIREMENTS
2.4 SYSTEM CONFIGURATION
2.5 INSTALLATION
2.6 TEST EQUIPMENT REQUIREMENTS
2.1 Introduction
VSP series power supply is configured, calibrated and tested prior to shipment.
This unit is therefore ready for immediate use upon receipt. The initial physical in-
spections should be made to ensure that no damage has been sustained during
shipment.
2.2 Unpacking
Inspect the shipping container before accepting it from the carrier. If damage to
the container is evident, remove the instrument from the container and visually in-
spect it for damage to the instrument case and parts.
If damage to the instrument is evident, a description of the damage should be
noted on the carrier’s receipt and signed by the driver or carrier agent. Save all ship-
ping containers and material for inspection.
Forward a report of any damage to the factory or the agent through which the
unit is procured.
Retain the original packing container if subsequent repackaging for return to the
factory were required. Repackaging is straightforward and is essentially the reverse
of the unpacking. Only subassemblies need to be repackaged for reshipment, use
the original containers.
Remove the Source module from its shipping container and inspect for any
damage to the front panel and display module. Also check for any optional parts
which may have been ordered by you. If the switch or display is heavily damaged or
is broken then DO NOT switch-ON the instrument.
Check the rear of the instrument for damage to Sockets or Fuse Holders. In-
spect also the POWER-ON switch on the front panel.

2.3 Input Power Requirements
The Model VSP power supply is configured at the factory to operate from 95-264 VAC at
47-63 Hz power line.
2.4 System Configuration
The Model VSP series power supply comes in ready to use fashion and does not
require any configuration in the field for operation in the local mode. For analog inter-
face refer to the connector details for the connections.
2.5 Installation
1. AC Input Power Connection
Connect a 3-pin power mains cord to the available line supply. Before connect-
ing line ensure the following:
a) The available line supply is compatible to your unit.
b) The available line supply point is capable of supplying the maximum peak current
and power.
2. Load Connections
Refer fig.2.1A for load connection in local and remote sensing mode, the unit
has5mm brass studson therear panel forload connectionsfor model upto 30A.The
bus bar is provided from 30A onwards.
For remote sensing and the current sharing option it is provided with separate 6
way terminal block. This is required if your load is far away & regulation needs to be
maintained at load terminals.
An output cable should be able to handle the full load current and maximum
voltage and power under worst case conditions of temperature, humidity, mechani-
cal abuse, and effects of long term aging.
3. Analog Interface Connections
A 25 pin D type connector & DIP switch is provided for remote analog interface to
the unit. There is 8 pin DIP switch associated with the function of analog interface.
Refer to section 3.3.5 of chapter 3 for switch settings.

4. Turn-On
Switch the POWER ON switch to the ON position. Soon the DPM will be turned
on & the output voltage & current are displayed, if output on-off switch is in ON posi-
tion. Voltmeter should display the voltage set by voltage control.
Check the current meter. It must show zero (very low) current under no load. If
not then please switch off the unit and call the service personnel.
For details of TURN ON CHECK refer section 3.5 of CHAPTER 3.
2.6 Test Equipment Requirements
The following instruments will be required to test the complete installation of the
unit.
1).A four and half digit or better digital multimeter for verifying the voltage and current
output of the unit.
2).A20MHz dual channeloscilloscope forverifyingthe RippleinOutput oftheSource.
3). A Resistive load or an Electronic Load to take an input to suit the maximum
output from the unit depending on the model and capacity of the channel of the
Source.

Fig 2.1a: CONNECTION DETAILS IN LOCAL & REMOTE INTERFACE
LOCAL MODE

Section 4
3.1 INTRODUCTION
3.2 FRONT PANEL DESCRIPTION
3.3 REAR PANEL DESCRIPTION
3.4 POWER ON CHECK
3.5 OPERATING INSTRUCTIONS IN LOCAL MODE
3.6 OPERATING INSTRUCTIONS IN ANALOG REMOTE
INTERFACE
3.7 OPERATING INSTRUCTIONS IN DIGITAL INTERFACE
TRIP INDICATIONS
3.1 INTRODUCTION
The VSP series Model is a variable switch mode power supply to provide wide
range of DC supply from 0 to full-scale specified voltage. This chapter explains the
operating procedure of the unit. The operation is very simple by providing POT con-
trol for voltage, current limit and over voltage protection limit and 8 way DIP switch
along with 25 Pin D type connector for the remote programming interface.
Optional RS232 interface or GPIB interface can be provided as per the order
placed. In case of RS232 interface, a slide switch on the rear panel facilitates either
RS232 communication interface orAnalog programming.
The unit is internally fan cooled. The air inlet vents are provided on the front
panel. The air outlet is a rectangular slotted area on the 1U high rear panel, and is
located between theA.C. input and D.C.output connectors.
The instrument front panel and rear panel are described first in detail, explain-
ing the layout, identification, function and usage of each item on the panel. The
Turn-on sequence and the procedure to use the major functions and operation of
unit in digital interface are also explained.At the end all the ALARM indications,
errors and warning signals are explained. In the same section procedures to clear
the TRIP and ALARM conditions are discussed.

3.2 FRONT PANEL DESCRIPTION
Figure 3.1 shows layout of front panel. On the front panel following controls
and indicators are provided.
1. Main ON/OFF switch with neon indication.
2. 3 digit display for Voltage/ Set Voltage/ Set Over Voltage indication
3. 3 digit display for Current/ Set Current indication.
4. 10 turn POT for voltage control.
5. 10 turn POT for current control.
6. 10 turn POT for over voltage protection control.
7. Push switch to view set parameters in SET mode.
8. Latch type Push switch for Output ON/OFF control.
9. LED indications for CV, CC, Output ON, Trip, Remote, V set, I set, O/V set and Set mode.
-The displayshows 3digit value forvoltage andcurrent parameters.The resolutionof indica-
tionis 0.1volt and0.1 ampfor voltageand currentparameters. Thedisplay is used to show
actualoutputvoltage andcurrentor toshowsetvalues ofvoltage,over voltageandset current
limitin theset mode. The set modeis activatedusing Setkey during output OFF condition.
-CV LEDindicates the constant voltage operationof powersupply.
-CC LEDindicatesconstant currentoperation ofpower supply.
-TRIP LEDbecomes ON eitherfor overvoltage tripconditionor forover temperaturetrip
condition.
-OutputON/OFF canbecontrolledby pushbuttonswitch (latch type)andLED turnsONif
outputisavailable.
-Remote LEDis providedfor the digital interface option.It lightsup whenthe powersupply is
controlledbyexternal digital interface.
-To viewthe set valuesof POTon the display press the SET key. AlsoLED’s for each POT
and common SET MODE Led is provided.
-Alsomonitoring terminals ofoutputare provided onfrontpanel so thatusercan verify the
outputwithcalibrated meter. Additional earth terminal isalso providedon frontpanel.
3.3 REAR PANEL DESCRIPTION
The rear panel of the unit is shown in fig 3.2. The mains input connection is made through
a 10A mains cord and is located on the right side of the unit at the rear. A 20A fuse of type
’F’ is used for line input range 95Vac to 264Vac) is also provided at input.At the center are
the oval shaped ventilation slots for air exhaust, for D.C. output 5mm brass studs or bus
bars (as per the current specifications) are provided, next to it is 6 way terminal block for
remote sensing and current share bus Further is the 25 pin D-type connector for analog
interfacing & the DIP switch for local & remote mode operations.Above the 25 pin D-type
connector the provision is made for digital interface connection, which can be either GPIB
or RS232.

1. 6. 7.
2. 3. 4. 5. 8.

3.3.1 LINE INPUT
The mains input range is clearly indicated on rear panel. The unit comes stan-
dard with a U.S. standard plug and a mains input rating of 95VAC to 265VAC, 50/
60Hz.
3.3.2 INPUT FUSE
This fuse protects the unit against short circuits and over loading. The 10A fuse of type ‘F’ is used for line input
range 176Vac to 264Vac and 20A fuse of type ’F’ is used for line input range 95Vac to 264Vac.
3.3.3 DC OUTPUT TERMINALS
VSP models with upto 30 amp output ratings have a pair of 5mm brass studs is provided
on the rear panel. Models above 30 amps have bus bars are provided. Output polarity is shown
near the terminal.
3.3.4 REMOTE SENSE CONNECTOR
6 Way terminals block is provided for remote sensing and current
share option.
1. +S: - Positive Sense terminal for remote sensing.
2. +Output: - Positive DC output terminal.
3. -Output: - Negative DC output terminal.
4. -S: - Negative Sense terminal for remote sensing.
5. NC
CS Bus: - Current share bus for parallel operation.
3.3.5 ANALOG INTERFACE CONNECTOR (Reference Fig. 3.1a and 3.1b in back of manual)
25 Pin D type connector is provided for remote analog interface, it is factory set to
operate through the front panel controls.
Pin no. 1: N.C.
Pin no. 2: N.C.
Pin no. 3: VPROGI-1 mA (typical) Current source for voltage programming.
Pin no. 4: VPIN - Input for voltage programming.
Pin no. 5: VPROGR - Resistance programming (0 to 4.85KOhms for full-scale volt-
age)
Pin no. 6: AGND3 - Common terminal for remote programming.
Pin no. 7: N.C.
Pin no. 8: N.C.
Pin no. 9: IPIN - Input for Current programming.
Pin no.10: IPROGI- 1mA (typical) Current source for Current programming.
Pin no.11: IPROGR - Resistance programming (0 to 4.85KOhms for full-scale cur-
rent)
Pin no.12: N.C.
Pin no.13: N.C.

Pin no.14: N.C.
Pin no.15: +12 V- Remote on/off relay supply +ve.
Pin no.16: AGND3 - Common terminal for remote programming.
Pin no.17: Remote On/Off - Remote on/off relay.
Pin no.18: AMX- Output Current monitoring. (Factory set to 0 to 5 volts for full scale)
Pin no.19: VMX - Output Voltage monitoring. (Factory set to 0 to 5 volts for full scale)
Pin no. 20: AGND3 - Common terminal for remote monitoring.
Pin no. 21: N.C.
Pin no. 22: VPSET - External programming option set for output voltage.
Pin no. 23: VMSET-External-monitoring option set for monitoringthe output voltage.
Pin no. 24: IPSET - External programming option set for output current.
Pin no. 25: IMSET - External monitoring option set for current.
3.3.6 DIP SWITCH DETAILS.
DIP Switch is provided on the rear panel to facilitates remote analog interface as
well as local mode interface in the power supply by just changing the switch positions
Switch no. 1 & 2 are associated with voltage programming
Switch no. 3 & 4 are associated with current programming
Switch no. 5 is associated with 0-5V & 0-10V programming
Switch no. 6 is associated 0-5V & 0-10V monitoring
Switch no. 7 is don’t care
Switch no. 8 is associated with remote ON-OFF.
3.3.7 DIGITAL COMMUNICATION INTERFACE (optional)
Digital communication interface either GPIB or RS-232 interface can be
incorporated with the system as per the order placed.As per the ordered digital
communication interface,the slots are available on the rear panel
The slide switch selects the RS232 interface & 9 pin D-Type connector is provided
on rear panel to connect the unit to PC.
NOTE: Refer Chapter 5 For Details Of Digital Communication Interface.
3.3 POWER ON CHECK
Keep the DIP switch settings for local mode operation. (Refer to 3.3.5)
After switching ON the unit, the display will show the actual voltage and current at the
output if output ON/OFF switch is in pressed position. If the switch is in OFF position then
the output voltage goes to 0V & displays zero.Also LED associated with key shows the
condition of output. If TRIP LED is ON then display show zero values and LED associated
with ON/OFF key remains off.

3.5 OPERATING INSTRUCTIONS IN LOCAL MODE
These are the instructions for operating the source in local mode. Refer following for DIP
switch settings to operate in Local mode.
3.5.1 Local Mode
Switch No. 12345678
Position On On On On On OFF X On
Refer fig. 2.1a for connection details in local & remote interface
Normally user can vary the V SET POT to change the output voltage while
working in constant voltage mode operation. I SET POT is used to set the output
current while working in constant current mode operation.
3.5.2 SET MODE OPERATION IN LOCAL MODE
User can view the set parameters using set mode operation before turning the
output ON. To enter the SET mode, switch off the ON OFF switch.
When SET key is pressed for the first time then SET LED turns ON and display
shows OVP value and OVP POT LED keeps on flashing. In this mode the OVP POT
can be used to change the over voltage limit
On pressing the SET key again the display shows the set voltage and VSET
POT LED keeps on flashing. In this mode the VSET POT can be used to change the
output voltage.
Onpressing the SETkey again the display showsthe set currentand ISET POT
LED keeps on flashing. In this mode the ISET POT can be used to change the output
current.
Set mode operation ends after pressing SET key fourth time & displays zero if the output
on off switch is off. At any instant, while in set mode, if output on off switch is pressed the
display displays the output voltage & current.

3.6 OPERATING INSTRUCTIONS IN ANALOG REMOTE INTERFACE
Remote Mode
Following are the positions of switches for the operating the source in remote mode by
external analog voltage and resistance.
3.6.1 Voltage Programming
Apply the input programming voltage of 0 to 5Volts or 0 to10 Volts between pin
4 & common control pin 6 of 25 pin D type connector for voltage programming & for
current programming between 9 & 6 (common control pin) of 25 pin D-Type connec-
tor.
8 pin DIP switch on rear panel:
Switch No. 12345678
Position Off Off Off Off X On
ON for 0-5V programming
OFF for 0-10V programming
OFF for 0-5V monitoring
ON for 0-10V monitoring
Don’t Care
Refer fig. 3.1a for remote voltage and current programming and monitoring
It also explains load connections required in this mode.
Note: Factory set for 0 to 5 volts for full scale output programming and monitoring.
3.6.2 Resistance Programming
For resistance programming standard resistor used is 4.85KOhms.
Following shows the DIP switch configuration required in this mode & explains the
connection of the resistor to the 25 pin D-type connector.
8 pin DIP switch on rear panel:
Switch No. 12345678
Position Off On Off On On X On
OFF for 0-5V monitoring
ON for 0-10V monitoring
Don’t Care

Refer figure 3.1b for external resistance programming 0 to 4.85kohms for full scale
voltage and current . It also shows the load connections required in this mode. As
shown in the figure for Voltage Control connect the resistance of 4.85 K ohms at
pin 4 & common control pin 6 of 25 pin D Type connector & for Current control
connect resistance between pin 9 & pin 6 (common control pin) of 25 pin D Type
connector.
3.6.3 Remote ON/OFF:
A 25 pin D type connector & DIP switch is provided for remote analog interface
to the unit. There is 8 pin DIP switch associated with the function of analog interface.
SW no. 8 on the rear 8 pin DIP switch is Remote ON/OFF control & must be always
on for terminal voltage ON when operated from the local controls.
For the remote control keep SW no. 8 OFF and connect switch across pin no. 16 &
17 of 25 pin D type connector.
3.6 OPERATING INSTRUCTIONS IN DIGITAL INTERFACE
To enable remote interface, the command for system to enter remote mode
must be entered through remote P.C. This will cause the remote LED on front panel
to glow; now no key on front panel will be detected. However the display will be
updated to indicate the entered value.
In GPIB interface proper address must be given.
To change the output voltage while working in constant voltage mode opera-
tion or to set the output current while working in constant current mode operation,
user has just to enter command (as specified in chapter 5) through remote PC.
There are simple commands to take the unit either in remote or local mode. The
status of the power supply can be easily read using specific commands. The output
can be turned ON or OFF as per requirements. Output ON is indicated by ON LED
on the front panel.Also the over voltage limit can be set. Whenever the output
voltage exceeds this maximum limit the trip condition occurs thereby resetting the
output.
The command summary is given in detail in chapter 5.
3.8 TRIP INDICATIONS
The VSP series power supplies has provision of Over Voltage & Over Tem-
perature protection. If at any time one of these conditions occurs, the unit will be
tripped. This means that the output voltage is made to be zero. This condition is
indicated by the Trip LED blinking.

3.8.1 RESETTING THE TRIP CONDITION
Assess as to why the trip has occurred. Then isolate the fault e.g., over voltage
trip condition can be reset by lowering the output voltage than OV trip level & then
toggling the input power will reset trip condition.
For resetting the over temp condition allow some time for cooling the heat sinks to change the status of thermal switch.
4.1 INTRODUCTION
4.2 PREVENTIVE MAINTENANCE
4.3 SERVICE INFORMATION
4.1 Introduction
This chapter contains the problems that may occur in the field in the event
of long use. The procedure to test the unit is explained under the proper section.
The individual is advised to use the correct procedure provided for the
purpose of operating the particular sequence to set proper voltages and current
required to test the proper working of the unit.
This unit has few boards and interconnections and the reliability is very
high. However, if a failure occurs the user himself might be able to fix the unit by
following the remedies given under particular complaint.
Read the manual completely in order to understand your unit better.
4.2 Preventive Maintenance
Please follow the following preventive steps to ensure the proper operation of your
instrument.
*Allow enough natural cooling (ventilation) around the unit.
*Avoid keeping tools, equipment etc. on the top cover.
* Keep the working area neat and clean always.
*Do not exceed the input/output limits at any time.
4.3 Complaints and Service Information
Some of the common problems that may occur and the remedy to put back
the instrument back in to a working condition as fast as possible are given below: