Tektronix Bench Test Instruments,Handheld Oscilloscopes Reference manual
Technical Reference
Bench Test Instruments and
Handheld Oscilloscopes
Basic Service
061-4124-02
Warning
The servicing instructions are for use by qualified
personnel only. To avoid personal injury, do not
perform any servicing unless you are qualified to
do so. Refer to all safety summaries prior to
performing service.
www.tektronix.com
Copyright © Tektronix, Inc. All rights reserved. Licensed software products are owned by Tektronix or its subsidiaries or
suppliers, and are protected by national copyright laws and international treaty provisions.
Tektronix products are covered by U.S. and foreign patents, issued and pending. Information in this publi cation supercedes
that in all previously published material. Specifications and price change privileges reserved.
TEKTRONIX and TEK are registered trademarks of Tektronix, Inc.
Contacting Tektronix
Tektronix, Inc.
14200 SW Karl Braun Drive
P.O. Box 500
Beaverton, OR 97077
USA
For product information, sal es, service, and technical support:
H In North America, call 1-800-833-9200.
H Worldwide, visit www.tektronix.com to find contacts in your area.
Service Reference
This manual contains the Performance Verification and Adjustment procedures
for many benchtop products. Table i lists the products supported by this manual.
Table i: Benchtop and handheld products supported by this manual
Products
PS280 and PS283 Power Supplies
PS2520, PS2520G, PS2521, and PS2521G Power Supplies
TAS 210 and TAS 220 Digital Oscilloscopes
TMM420 Digital Multimeter
THM500 Series Multimeter/Scope
Service information of products not provided in this manual may be available
under separate cover. Table ii provides a list of many handheld and benchtop
instruments and their service documentation.
Table ii: Handheld and benchtop instruments service manuals
Product Tektronix part number
212 Oscilloscope 070-5053-00
214 Oscilloscope 070-5055-00
214 Storage Oscilloscope 070-1483-00
221 Oscilloscope 070-1573-01
222 Digital Storage Oscilloscope 070-7459-00
222A DSO:
B010100 thru B039999
B040000 and above
222PS Power Scout 070-8098-02
224 Digital Storage Oscilloscope 070-8405-02
305 DMM Oscilloscope 070-2423-01
314 Storage Oscilloscope 070-1824-00
335 Oscilloscope 070-1943-01
336 Digital Storage Oscilloscope 070-4421-00
2201 Portable Oscilloscope 070-7189-00
2205 Oscilloscope 070-6716-00
070-8330-00
070-8330-02
Bench Test Instruments and Handheld Oscilloscopes Basic Service
i
Service Reference
Table ii: Handheld and benchtop instruments service manuals (cont.)
Product Tektronix part number
2211 Oscilloscope 070-7234-00
2214 Digital Storage Oscilloscope 070-7783-00
2220 Digital Storage Oscilloscope 070-5302-00
2221A Oscilloscope:
B010100 to B019999
B020000 and above
2225 Oscilloscope 070-6299-00
2230 Digital Storage Oscilloscope 070-4999-00
2232 Digital Storage Oscilloscope:
B010100 to B029999
B030000 and above
2235 AN/USM-488 Oscilloscope 070-4977-00
2245 Portable Oscilloscope 070-6276-00
070-8157-01
070-8549-00
070-7067-01
070-8548-00
2245A Portable Oscilloscope:
B010100 to B015999
B016000 and above
2246A Portable Oscilloscope 070-6555-00
2246/1Y/2R/2246 Mod A 070-7062-00
2247A Portable Oscilloscope 070-6367-00
2252 Portable Oscilloscope 070-7838-01
2335 Oscilloscope 070-4116-00
2336 Oscilloscope 070-4118-00
2336YA Oscilloscope 070-5011-00
2337 Oscilloscope 070-4120-00
TAS 455/465 Oscilloscope 070-8524-02
TAS 465 Oscilloscope 070-9403-00
TAS 475/485 Oscilloscope:
B010100 to B020099
B020100 and above
TDS 210/220 Oscilloscope 070-9693-01
TDS 310/320/350 Oscilloscope 070-8570-05
TDS 340/340A/360/380 Oscilloscope 070-9435-02
070-6557-00
070-7672-00
070-8878-01
070-9404-00
THS 710/720/730 Oscilloscope 070-9246-03
ii
Bench Test Instruments and Handheld Oscilloscopes Basic Service
General Safety Summary
Review the following safety precautions to avoid injury and prevent damage to
the products in this manual or any products connected to them. To avoid
potential hazards, use these products only as specified.
Only qualified personnel should perform service procedures.
While using these products, you may need to access other parts of the system.
Read the General Safety Summary in other system manuals for warnings and
cautions related to operating the system.
ToAvoidFireor
Personal Injury
Use Proper Power Cord. To avoid fire hazard, use only the power cord specified
for the product you are using.
Use Proper Voltage Setting. B efore applying power, ensure that the line selector is
in the proper position for the power source being used.
Connect and Disconnect Properly. Do not connect or disconnect probes or test
leads while they are connected to a voltage source.
Ground the Product. Some of these products are grounded through the grounding
conductor or the power cord. To avoid electric shock, the grounding conductor
must be connected to earth ground. Before making connections to the input or
output terminals of the product you are using, ensure that the product is properly
grounded.
Observe All Terminal Ratings. To avoid fire or shock hazard, observe all ratings
and markings on the product you are using. Consult the product manual for
further ratings information before making connections to the product.
Do not apply a potential to any terminal, including the common terminal, that
exceeds the maximum rating of that terminal.
Replace Batteries Properly. Replace batteries only with the proper type and rating
specified.
Recharge Batteries Proper ly. Recharge batteries for the recommended charge
cycle only .
Use Proper AC Adapter. Use only the AC adapter specified for the product you
are using.
Bench Test Instruments and Handheld Oscilloscopes Basic Service
iii
General Safety Summary
Do Not Operate Without Covers. Do not operate these products with covers or
panels removed.
Use Proper Fuse. Use only the fuse type and rating specified for the product you
are using.
Avoid Exposed Circuitry. Do not touch exposed connections and components
when power is present.
Do Not Operate in Wet/Damp Conditions. To avoid electric shock, do not operate
these products in wet or damp conditions.
Do Not Operate in Explosive Conditions. To avoid injury or fire hazard, do not
operate these products in an explosive atmosphere.
Keep Product Surfaces Clean and Dry. To avoid electric shock and erroneous
readings, keep probe surfaces clean and dry.
Symbols and Terms
Provide Proper Ventilation. Refer to the product installation instructions for details
on installing the product so it has proper ventilation.
Terms in this Manual. These terms may appear in this manual.
WARNING. Warning statements identify conditions or practices that could result
in injury or loss of life.
CAUTION. Caution statements identify conditions or practices that could result in
damage to this product or other property.
Terms on the Products. These terms may appear on the product:
DANGER indicates an injury hazard immediately accessible as you read the
marking.
WARNING indicates an injury hazard not immediately accessible as you read the
marking.
CAUTION indicates a hazard to property including the product.
iv
Bench Test Instruments and Handheld Oscilloscopes Basic Service
General Safety Summary
Symbols on the Product. The following symbols may appear on the product:
DANGER
High Voltage
Protective Ground
(Earth) Terminal
ATTENTION
Refer to Manual
Double
Insulated
Bench Test Instruments and Handheld Oscilloscopes Basic Service
v
Service Safety Summary
Only qualified personnel should perform service procedures. Read this Service
Safety Summary and the General Safety Summary before performing any service
procedures.
Do Not Service Alone. Do not perform internal service or adjustments of this
product unless another person capable of rendering first aid and resuscitation is
present.
Disconnect Power. To avoid electric shock, disconnect the main power by means
of the power cord or, if provided, the power switch.
Use Caution When Servicing the CRT. To avoid electric shock or injury, use
extreme caution when handling the CRT. Only qualified personnel familiar with
CRT servicing procedures and precautions should remove or install the CRT.
CRTs retain hazardous voltages for long periods of time after power is turned off.
Before attempting any servicing, discharge the CRT by shorting the anode to
chassis ground. When discharging the CRT, connect the discharge path to ground
and then the anode. Rough handling may cause the CRT to implode. Do not nick
or scratch the glass or subject it to undue pressure when removing or installing it.
When handling the CRT, wear safety goggles and heavy gloves for protection.
Use Care When Servicing With Power On. Dangerous voltages or currents may
exist in this product. Disconnect power, remove battery (if applicable), and
disconnect test leads before removing protective panels, soldering, or replacing
components.
To avoid electric shock, do not touch exposed connections.
X-Radiation. To avoid x-radiation exposure, do not modify or otherwise alter the
high-voltage circuitry or the CRT enclosure. X-ray emissions generated within
this product have been sufficiently shielded.
vi
Bench Test Instruments and Handheld Oscilloscopes Basic Service
Preventing Electrostatic Discharge
CAUTION. Static discharge can damage internal semiconductor components.
Follow the guidelines listed below to avoid product damage.
When performing service that requires internal access to an instrument, adhere to
the following precautions to avoid damaging internal modules or their components:
H Avoid handling modules or components in areas that have floors or work
surfaces capable of generating a static charge.
H Spray carpeted work areas with a solution of equal parts of water and fabric
softener.
H Wear clothing made from materials that do not accumulate static charges.
Avoid Wool (and some artificial fibers) which build up static charges readily;
wear cotton which conducts electricity and resists static accumulation.
H Minimize the handling of static-sensitive devices.
H Transport and store static-sensitive devices in their protected containers or on
a metal rail. Label any package that contains static-sensitive parts.
H Service instruments and modules at grounded, static-free work stations.
H Do not allow devices capable of generating a static charge on a work station
surface.
H Wear a grounding strap while working with static-sensitive devices.
H Handle circuit boards by their edges, if possible.
H Do not slide static-sensitive components over any surface.
H Do not use high-velocity compressed air to clean or dry components or
modules.
Bench Test Instruments and Handheld Oscilloscopes Basic Service
vii
Preventing Electrostatic Discharge
viii
Bench Test Instruments and Handheld Oscilloscopes Basic Service
Preface
This manual contains service information for a wide range of handheld and
benchtop products. Each section covers a product or related series of products
and includes the following information:
H A product description that details instrument functions, capabilities, and
recommended uses
H A front panel illustration
H A set of electrical, mechanical, environmental, and physical specifications
H A performance verification procedure to ensure the instrument meets
specifications
H An adjustment procedure to return the instrument to factory calibration (not
included for all instruments)
The information contained in this manual is current at the date of publication and
is typical or suggested, not guaranteed. Since manual updates occur at approximately six month intervals, information may be incomplete or missing in some
versions.
Some instruments have optional service information available under separate
cover. This manual does not duplicate information from optional service
manuals. Refer to the optional accessories list in your user manual for Tektronix
part numbers of optional service manuals. A list of Handheld and Benchtop
instruments manuals can also be found in Table ii on Page i.
NOTE. This manual provides the necessary service information to verify that
your instrument is working properly. Should you have service-related questions
not covered in either this manual or in an optional service manual, please
contact your Tektronix Service Center for additional information.
For product warranty information, refer to the user manual supplied with your
instrument.
Bench Test Instruments and Handheld Oscilloscopes Basic Service
ix
Preface
x
Bench Test Instruments and Handheld Oscilloscopes Basic Service
Instructions Manual
PS280 and PS283
Power Supplies
070-9894-01
www.tektronix.com
Table of Contents
PS280 and PS283 Specifications 3..............................
PS280 and PS283 Performance Verification 7....................
Test Equipment 8..................................................
Constant Current Load Regulation Check 9.............................
Constant Current Ripple and Noise Check 11............................
Constant Voltage Regulation Check 13..................................
PS280 and PS283 Adjustment Procedures 15.....................
List of Adjustments 15..............................................
Test Equipment 16..................................................
Preparation for Adjustment 16........................................
Independent Mode Adjustments 19.....................................
Series Tracking Mode Adjustments 21..................................
Parallel Tracking Mode Adjustments 22.................................
5 V Fixed Output Adjustments 23......................................
Bench Test Instruments and Handheld Oscilloscopes Basic Service
i
Table of Contents
ii
Bench Test Instruments and Handheld Oscilloscopes Basic Service
PS280 and PS283 Power Supplies
The Tektronix PS280 and PS283 Laboratory DC Power Supplies are multifunction benchtop or portable instruments. These regulated triple output power
supplies provide one fixed 5 V, 3 A output suitable for powering logic circuits
and two variable 0 to 30 V outputs useful in a wide variety of test and experimental uses.
The current output of the PS280 varies from 0 to 2 A. The current output of the
PS283 varies from 0 to 1 A. In all other respects, the instruments are identical.
Unless otherwise noted, descriptions and procedures in this manual apply to both
instruments.
The front panel switches provide three modes of operation for the PS280 and
PS283 power supplies:
H Independent mode: the output voltage and current of each supply is
controlled independently.
H Series mode: the variable outputs are connected in series and the controls of
the MASTER power supply adjust the voltages or currents of both supplies.
Series mode allows the supplies to vary from 0 to 60 V at 0 to 2 A for the
PS280 and 0 to 60 V at 0 to 1 A for the PS283.
H Parallel mode: the variable outputs are connected in parallel and the controls
of the MASTER power supply adjust the voltages or currents of both
supplies. Parallel mode allows the supplies to vary from 0 to 4 A at 0 to
30 V for the PS280 and 0 to 2 A at 0 to 30 V for the P S283.
Figure 1: PS280 DC Power Supply
Bench Test Instruments and Handheld Oscilloscopes Basic Service
1
PS280 and PS 283 Power Supplies
2
Bench Test Instruments and Handheld Oscilloscopes Basic Service
PS280 and PS283 Specifications
The characteristics listed in this section apply under the following conditions:
H The instrument operates in a 0_ to 40_ C(32_ to 104_ F) ambient environ-
ment, unless otherwise noted.
H The instrument warms up for at least twenty minutes.
NOTE. All characteristics are warranted unless marked “typical”. Typical
characteristics are not guaranteed but are provided for the convenience of the
user.
Table 1: Operational characteristics
Characteristic Description
Outputs Onefixed5VDC,twovariable0to30VDC
Voltage (5 V Fixed Supply) 5.0 VDC ±0.25 VDC at 3.0 A maximum, foldback current limited
Voltage (0 to 30 V Supplies) PS280: 0 to 30 VDC constant at 2.0 A constant, maximum
PS283: 0 to 30 VDC constant at 1.0 A constant, maximum
Line regulation
5V <5mV
CV PS280: ≤0.01% + 3 mV
PS283: ≤0.01% + 5 mV
CC ≤0.2% + 3 mA
Load regulation
5V ≤0.2%
CV ≤0.01% + 3 mV (rating current ≤3A)
≤0.01% + 5 mV (rating current >3 A PS280)
≤300 mV (0 to 60 VDC single series tracking supply)
CC ≤0.2% + 3 mA
Bench Test Instruments and Handheld Oscilloscopes Basic Service
3
PS280 and PS283 Specifications
Table 1: Operational characteristics (cont.)
Characteristic Description
Ripple and Noise
5V ≤2mV
CV 5Hzto1MHz:≤1mV
CC ≤3mA
RMS
RMS
RMS
Temperature coefficient (CV) ≤300 ppm/ _C
Recovery time (CV) ≤100 s (time to recover after a 50% load change with 0.5 A
minimum)
Tracking error (SLAVE) ≤0.5% + 10 mV of the MASTER supply
Indicator Two 3½ digit, 0.5 inch LED panel displays
Meter indicators 0to30VDC±(0.5% of RDG + 2 digits)
0to2A±(0.5% of RDG + 2 digits)
Insulation
Chassis to terminals ≥20 MΩ at 500 VDC
Chassis to AC cord ≥30 MΩ at 500 VDC
Table 2: Electrical characteristics
Characteristic Description
Line Voltage 90 to 110, 108 to 132, 198 to 242, and 216 to 250 VAC
Line Frequency 50 to 60 Hz
Power Consumption PS280: 348 VA, 250 W maximum
PS282: 254 VA, 172 W maximum
Table 3: Environmental characteristics
Characteristic Description
Operating Temperature 0° to 40° C(32° to 104° F), ≤70% relative humidity
Nonoperating Temperature -- 1 0 ° to +70° C(14° to 158° F), ≤80% relative humidity
4
Bench Test Instruments and Handheld Oscilloscopes Basic Service
Table 4: Physical characteristics
Characteristic Description
Width 255 mm (10.04 inch)
Height 145 mm (5.71 inch)
Depth 335 mm (13.19 inch)
Weight PS280: 11.5 kg (25.3 lb)
PS283: 9.0 kg (19.8 lb)
PS280 and PS283 Specifications
Bench Test Instruments and Handheld Oscilloscopes Basic Service
5
PS280 and PS283 Specifications
6
Bench Test Instruments and Handheld Oscilloscopes Basic Service
PS280 and PS283 Performance Verification
This section contains procedures to verify that PS280 or PS283 power supplies
perform as warranted. Implement the performance verification procedures
whenever the accuracy or function of your instrument is in question.
The performance verification procedures provide a valid confirmation of
instrument electrical characteristics and function under the following conditions:
H The instrument operates in a 20_ to 30_ C(68_ to 104_ F) ambient
environment.
H The instrument warms up for at least 20 minutes before the verification
begins.
H The cabinet remains installed on the instrument.
The PS280 and PS283 performance verification consists of the checks listed in
Table 5.
Table 5: Performance verification checks
Constant Current Load Regulation Check
MASTER Current Regulation (INDEP mode)
SLAVE Current Regulation (INDEP m ode)
MASTER Current Regulation (PARALLEL mode)
Constant Current Ripple and Noise Check
MASTER Current Ripple
SLAVE Current Ripple
Constant Voltage Regulation Check
MASTER Voltage Regulation
SLAVE Voltage Regulation
5 V Fixed Voltage Regulation
The performance verification procedure should be performed annually or after
every 2000 hours of operation if used infrequently.
Bench Test Instruments and Handheld Oscilloscopes Basic Service
7
PS280 and PS283 Performance Verification
Test Equipment
The performance verification procedures use external traceable test equipment to
directly check warranted characteristics.
Alternative test equipment must meet or exceed the intended minimum
requirements. If you substitute equipment, you may need to modify the
performance verification procedures.
NOTE. Before beginning the performance verification procedures, warm up the
test equipment according to the manufacturer’s recommendations.
Table 6: Performance verification and adjustment test equipment
Description Minimum requirements Example product
Oscilloscope 50 MHz, 3% vertical deflection accuracy Tektronix TDS300 Series Oscilloscope
Digital Multimeter 35 V, 4 A, ±0.1% Accuracy Tektronix DMM914 Digital Multimeter
Fixed Resistive Loads 20 Ω 30 W
10 Ω 30 W
2 Ω 5W
1 Ω 30 W
7 Ω 140 W
0.5 Ω 5W
15 Ω 70 W
30 Ω 140 W
7.5 Ω 140 W
30 Ω 40 W
60 Ω 70 W
Variable Resistive Load 0to2Ω 30 W
Shorting Strap with Alligator Clips Insulated
8
Bench Test Instruments and Handheld Oscilloscopes Basic Service
Constant Current Load Regulation Check
To check the constant current load regulation of your power supply, perform the
following tests.
PS280 and PS283 Performance Verification
MASTER Current
Regulation (INDEP mode)
RL2
DMM
Shorting strap
RL1
Power supply
-- +
Figure 2: Constant current test setup
The following check verifies the INDEP mode MASTER current regulation
performance.
1. Set the power supply to the INDEP operating mode by disengaging both
TRACKING mode switches (both switches out).
2. Set the power supply MASTER AMPS/VOLTS selection switch to AMPS.
3. Set up the digital multimeter to measure 25 VDC.
4. Connect the digital multimeter to the + and -- terminals of the power supply
MASTER output.
5. Adjust the power supply MASTER VOLTAGE control until the multimeter
reads 25 VDC.
6. Disconnect the digital multimeter from the power supply.
7. Set the digital multimeter to measure a DC current of at least 1 A (PS280) or
0.5 A (PS283).
8. Connect the digital multimeter and load resistors to the + and -- terminals of
the power supply MASTER output as shown in Figure 2. See Table 7 for the
appropriate load resistor values.
9. Verify that the power supply output current varies less than 0.2%
while shunting load resistor RL1 with the shorting strap. See Figure 2 above.
Bench Test Instruments and Handheld Oscilloscopes Basic Service
±3mA
9
PS280 and PS283 Performance Verification
Table 7: Load resistor values for current checks
PS280 PS283
SLAVE Current Regulation
(INDEP Mode)
Mode
INDEP 20 Ω,30W 2 Ω,5W 20 Ω,30W 2 Ω,5W
PARALLEL 10 Ω,30W 1 Ω,30W 10 Ω,30W 1 Ω,30W
RL1
RL2 RL1 RL2
The following check verifies the INDEP mode SLAVE current regulation
performance.
1. Set the power supply SLAVE AMPS/VOLTS meter selection switch to
AMPS.
2. Set up the digital multimeter to measure 25 VDC.
3. Connect the digital multimeter to the + and -- terminals of the power supply
SLAVE output.
4. Adjust the power supply SLAVE VOLTAGE control until the multimeter
reads 25 VDC.
5. Disconnect the digital multimeter from the power supply.
6. Set the digital multimeter to measure a DC current of at least 1 A (PS280) or
0.5 A (PS283).
MASTER Current
Regulation
(PARALLEL Mode)
7. Connect the digital multimeter and load resistors to the + and -- terminals of
the power supply SLAVE output as shown in Figure 2. See Table 7 for the
appropriate load resistor values.
8. Verify that the power supply output current varies less than 0.2%
±3mA
while shunting load resistor RL1 with the shorting strap. See Figure 2 above.
The following check verifies the PARALLEL mode MASTER current regulation
performance.
1. Set the power supply to the PARALLEL operating mode by engaging both
TRACKING mode switches (both switches in).
2. Set up the digital multimeter to measure 25 VDC.
3. Connect the digital multimeter to the + and -- terminals of the power supply
MASTER output.
4. Adjust the power supply MASTER VOLTAGE control until the digital
multimeter reads 25 VDC .
5. Disconnect the digital multimeter from the power supply.
10
Bench Test Instruments and Handheld Oscilloscopes Basic Service
6. Set the digital multimeter to measure a DC current of at least 1 A (PS280) or
0.5 A (PS283).
7. Connect the digital multimeter and load resistors to the + and -- terminals of
the power supply MASTER output as shown in Figure 2. See Table 7 for the
appropriate load resistor values.
8. Verify that the power supply output current varies less than 0.2% ±5mA
while shunting load resistor RL1 with the shorting strap. See Figure 2 above.
Constant Current Ripple and Noise Check
To check the constant current ripple and noise performance of your power
supply, perform the following tests.
PS280 and PS283 Performance Verification
MASTER Current Ripple
Power supply
-- +
R
S
R
L
Test oscilloscope
Figure 3: Constant current ripple and noise test setup
The following check verifies the MASTER current ripple.
1. Set the power supply to the INDEP operating mode by disengaging both
TRACKING switches (both switches out).
2. Set the power supply MASTER AMPS/VOLTS meter selection switch to
VOLTS.
3. Set the power supply to 25 VDC using the digital display.
4. Connect the test oscilloscope and load resistors to the + and -- terminals of
the MASTER output as shown in Figure 3. See Table 8 for the appropriate
load resistor values.
5. Verify that the peak-to-peak ripple viewed on the oscilloscope is less than
3mV.
Bench Test Instruments and Handheld Oscilloscopes Basic Service
11
PS280 and PS283 Performance Verification
6. Set the power supply to the PARALLEL operating mode by engaging both
TRACKING mode switches (both switches in).
7. Verify that the peak-to-peak ripple viewed on the oscilloscope is less than
2.5 mV.
8. Set the power supply to the SERIES operating mode by disengaging the
right TRACKING mode switch (switch out).
9. Verify that the peak-to-peak ripple viewed on the oscilloscope is less than
5mV.
Table 8: Load resistor values for ripple checks
PS280 PS283
SLAVE Current Ripple
Mode
INDEP 15 Ω,70W 0.5 Ω,5W 30 Ω,40W 0.5 Ω,5W
PARALLEL 7 Ω, 140 W 10 Ω,30W 15 Ω,70W 0.5 Ω,5W
R
L
R
S
R
L
R
S
The following check verifies the SLAVE current ripple.
1. Set the power supply to INDEP operating mode by disengaging both
TRACKING switches (both switches out).
2. Set the power supply SLAVE AMPS/VOLTS meter switch to VOLTS.
3. Set the power supply to 25 VDC using the digital display.
4. Connect the test oscilloscope and load resistors to the + and -- terminals of
the SLAVE output as shown in Figure 3. See Table 8 for the appropriate load
resistor values.
5. Verify that the peak-to-peak ripple viewed on the oscilloscope is less than
3mV.
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Bench Test Instruments and Handheld Oscilloscopes Basic Service
Constant Voltage Regulation Check
To check the constant voltage regulation of your power supply, perform the
following tests.
Power supply DMM
Figure 4: Constant voltage test setup
-- +
PS280 and PS283 Performance Verification
R
L
MASTER Voltage
Regulation
The following check verifies the MASTER voltage regulation performance.
1. Set the power supply to the INDEP operating mode by disengaging both
TRACKING mode switches (both switches out).
2. Set up the digital multimeter to measure 60 VDC.
3. Connect the digital multimeter and load resistors to the + and -- terminals of
the power supply MASTER output as shown in Figure 4. See Table 9 for the
appropriate load resistor values.
4. Verify that you can adjust the power supply from 0 to 30 V.
5. Set the power supply to the SERIES operating mode by engaging the left
TRACKING mode switch (switch in) and disengaging the right TRACKING
mode switch (switch out).
6. Verify that you can adjust the power supply from 0 to 60 V.
7. Set the power supply to the PARALLEL operating mode by engaging both
TRACKING mode switches (both switches in).
8. Verify that you can adjust the power supply from 0 to 30 V.
Bench Test Instruments and Handheld Oscilloscopes Basic Service
13
PS280 and PS283 Performance Verification
Table 9: Load resistor values for voltage checks
PS280 PS283
SLAVE Voltage Regulation
5 V Fixed Voltage
Regulation
Mode
INDEP 15 Ω,70W 30 Ω,40W
SERIES 30 Ω, 140 W 60 Ω,70W
PARALLEL 7.5 Ω, 140 W 15 Ω,70W
5V FIXED 1.7 Ω,20W 1.7 Ω,20W
R
L
R
L
The following check verifies the SLAVE voltage regulation performance.
1. Set the power supply to the INDEP operating mode by disengaging both
TRACKING mode switches (both switches out).
2. Set up the digital multimeter to measure 30 VDC.
3. Connect the digital multimeter and load resistors to the + and -- terminals of
the SLAVE output as shown in Figure 4. See Table 9 for the appropriate load
resistor values.
4. Verify that you can adjust the power supply from 0 to 30 V.
The following check verifies the 5 V fixed voltage regulation performance.
1. Set up the digital multimeter to measure 5 VDC.
14
2. Connect the digital multimeter and load resistors to the 5V FIXED 3A
terminals. Use the test setup illustrated in Figure 4. See Table 9 for the
appropriate load resistor values.
3. Verify that the power supply maintains an output of 5 V,
±0.25 V.
Bench Test Instruments and Handheld Oscilloscopes Basic Service
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