User Manual
PS280 & PS283
DC Power Supplies
070-8355-03
Copyright T ektronix, Inc. 1991. All rights reserved.
T ektronix products are covered by U.S. and foreign patents, issued and
pending. Information in this publication supercedes that in all previously
published material. Specifications and price change privileges reserved.
T ektronix, Inc., P.O. Box 1000, Wilsonville, OR 97070–1000
TEKTRONIX and TEK are registered trademarks of T ektronix, Inc.
WARRANTY
Tektronix warrants that this product will be free from defects in materials and
workmanship for a period of one (1) year from the date of shipment. If any such product
proves defective during this warranty period, Tektronix, at its option, either will repair the
defective product without charge for parts and labor, or will provide a replacement in
exchange for the defective product.
In order to obtain service under this warranty, Customer must notify Tektronix of the defect
before the expiration of the warranty period and make suitable arrangements for the
performance of service. Customer shall be responsible for packaging and shipping the
defective product to the service center designated by Tektronix, with shipping charges
prepaid. Tektronix shall pay for the return of the product to Customer if the shipment is to
a location within the country in which the Tektronix service center is located. Customer
shall be responsible for paying all shipping charges, duties, taxes, and any other charges for
products returned to any other locations.
This warranty shall not apply to any defect, failure or damage caused by improper use or
improper or inadequate maintenance and care. Tektronix shall not be obligated to furnish
service under this warranty a) to repair damage resulting from attempts by personnel other
than Tektronix representatives to install, repair or service the product; b) to repair damage
resulting from improper use or connection to incompatible equipment; or c) to service a
product that has been modified or integrated with other products when the effect of such
modification or integration increases the time or difficulty of servicing the product.
THIS WARRANTY IS GIVEN BY TEKTRONIX WITH RESPECT TO THIS
PRODUCT IN LIEU OF ANY OTHER WARRANTIES, EXPRESSED OR
IMPLIED. TEKTRONIX AND ITS VENDORS DISCLAIM ANY IMPLIED
WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR
PURPOSE. TEKTRONIX’ RESPONSIBILITY TO REPAIR OR REPLACE
DEFECTIVE PRODUCTS IS THE SOLE AND EXCLUSIVE REMEDY
PROVIDED TO THE CUSTOMER FOR BREACH OF THIS WARRANTY.
TEKTRONIX AND ITS VENDORS WILL NOT BE LIABLE FOR ANY
INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
IRRESPECTIVE OF WHETHER TEKTRONIX OR THE VENDOR HAS
ADVANCE NOTICE OF THE POSSIBILITY OF SUCH DAMAGES.
Table of Contents
General Safety Summary iii. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Getting Started 1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Preparing the Power Supply for Use 2. . . . . . . . . . . . . . . . . . . . .
Front Panel 4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Turning On the Instrument 8. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Reference 9. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Constant Voltage/Constant Current Crossover 9. . . . . . . . . . . . .
Setting the Current Limit 10. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
T est Modes 11. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Independent Modes 11. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Tracking Modes 20. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Appendix A: Specifications 25. . . . . . . . . . . . . . . . . . . . . . . . . . .
Appendix B: Maintenance 29. . . . . . . . . . . . . . . . . . . . . . . . . . .
Cleaning 29. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Preparing for Shipment 29. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Troubleshooting 30. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Appendix C: Replaceable Parts 33. . . . . . . . . . . . . . . . . . . . . . .
Standard Accessories 33. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Optional Accessories 33. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
PS280 & PS283 User Manual
i
T able of Contents
List of Figures
Figure 1: Line Voltage Selectors, Power Input,
and Fuse Locations 2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Figure 2: PS280 or PS283 Front Panel 4. . . . . . . . . . . . . . . . . . .
Figure 3: Constant Voltage/Constant Current Crossover 10. . . . . .
Figure 4: Independent Floating Application 12. . . . . . . . . . . . . . .
Figure 5: Independent Common Ground-Referenced
Application 14. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Figure 6: Independent Ground-Referenced Split Application 15. .
Figure 7: Three Ground-Referenced Negative Power Supplies 16
Figure 8: Three Ground-Referenced Positive Power Supplies 17.
Figure 9: Independent Positive Stacked Application 18. . . . . . . . .
Figure 10: Independent Negative Stacked Application 19. . . . . . .
Figure 11: Series Tracking Inside the PS280 or PS283 20. . . . . . .
Figure 12: Series Tracking Application 21. . . . . . . . . . . . . . . . . . .
Figure 13: Parallel Tracking Inside the PS280 or PS283 23. . . . .
Figure 14: Parallel Tracking Application 24. . . . . . . . . . . . . . . . .
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PS280 & PS283 User Manual
General Safety Summary
Review the following safety precautions to avoid injury and prevent
damage to this product or any products connected to it.
Injury Precautions
Use Proper Power Cord
T o avoid fire hazard, use only the power cord specified for this
product.
Avoid Electric Overload
T o avoid electric shock or fire hazard, do not apply a voltage to a
terminal that is outside the range specified for that terminal.
Ground the Product
This product is grounded through the grounding conductor of the
power cord. T o avoid electric shock, the grounding conductor must
be connected to earth ground. Before making connections to the
input or output terminals of the product, ensure that the product is
properly grounded.
Do Not Operate Without Covers
T o avoid electric shock or fire hazard, do not operate this product
with covers or panels removed.
Use Proper Fuse
T o avoid fire hazard, use only the fuse type and rating specified for
this product.
PS280 & PS283 User Manual
iii
General Safety Summary
Do Not Operate in Wet/Damp Conditions
T o avoid electric shock, do not operate this product in wet or damp
conditions.
Do Not Operate in Explosive Atmosphere
T o avoid injury or fire hazard, do not operate this product in an
explosive atmosphere.
Product Damage Precautions
Use Proper V oltage Setting
Before applying power, ensure that the line selector is in the proper
position for the power source being used.
Provide Proper Ventilation
T o prevent product overheating, provide proper ventilation.
Do Not Operate With Suspected Failures
If you suspect there is damage to this product, have it inspected by
qualified service personnel.
Safety Terms and Symbols
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.
iv
PS280 & PS283 User Manual
General Safety Summary
CAUTION. Caution statements identify conditions or practices that
could result in damage to this product or other property.
Terms on the Product
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.
Symbols on the Product
The following symbols may appear on the product:
DANGER
High Voltage
Protective Ground
(Earth) T erminal
Certifications and Compliances
CSA Certified Power Cords
CSA Certification includes the products and power cords appropriate
for use in the North America power network. All other power cords
supplied are approved for the country of use.
PS280 & PS283 User Manual
ATTENTION
Refer to
Manual
Double
Insulated
v
General Safety Summary
vi
PS280 & PS283 User Manual
Getting Started
The Tektronix PS280 or PS283 Laboratory DC Power Supply is a
multifunction bench or portable instrument. This regulated power
supply provides a fixed 5 V output for powering logic circuits and
two variable outputs for a wide variety of test and experimental uses.
The PS280 or PS283 contains two identical, independently adjustable
DC power supplies that you can vary from 0 to 30 V. The current on
the PS280 variable power supplies varies from 0 to 2 A. The current
on the PS283 variable power supplies 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.
Front panel switches select one of three modes of operation:
H Independent — In this mode, the output voltage and current of
each supply can be controlled independently.
H Series — In this tracking mode, the variable outputs are
connected in series, and the controls of the master power supply
adjust the voltages or currents of both power supplies. Series
mode allows the power supplies to be varied from 0 to 60 V at 0
to 2 A for the PS280, or 0 to 1 A for the PS283.
H Parallel — In this tracking mode, the variable outputs are
connected in parallel, and the controls of the master power supply
adjust the voltages or currents of both power supplies. Parallel
mode allows the power supplies to be varied from 0 to 4 A for the
PS280 at 0 to 30 V, or from 0 to 2 A at 0 to 30 V for the PS283.
PS280 & PS283 User Manual
1
Getting Started
Preparing the Power Supply for Use
Check the following items prior to operating the Laboratory DC
Power Supply for the first time (see Figure 1 for locations of items 1
through 3):
Figure 1: Line Voltage Selectors, Power Input, and Fuse Locations
1
3
2
CAUTION. To prevent damage to the instrument, set the line voltage
selectors to the proper voltage setting and install the correct line
voltage fuse before operating the equipment.
1. Set the line voltage selectors to the input line voltage. These
selectors connect internal wiring for various line voltages. This
product is intended to operate from a power source that does not
supply more than 250 V
between either supply conductor and ground. For line voltage
ranges, refer to Appendix A: Specifications on page 25.
WARNING. To prevent electrical shock, unplug the power cord and
disconnect the test leads from the circuit before checking or
replacing the fuse.
2. Check that the correct line fuse is installed. The line fuse
provides protection if the equipment malfunctions or an overload
2
between the supply conductors or
RMS
PS280 & PS283 User Manual
Getting Started
occurs. Refer to Appendix C: Replaceable Parts on page 33 for
fuse part numbers.
WARNING. To prevent electrical shock, connect the power cord to a
properly grounded power source. The outside (ground) of this
connector is connected through the equipment to the power source
ground. Do not remove the ground lug from the power cord for any
reason.
3. Connect the input power cord. Use only the power cords specified
for this equipment. Refer to Appendix C: Replaceable Parts on
page 33 for power cord part numbers.
PS280 & PS283 User Manual
3
Getting Started
Front Panel
Figure 2 shows the front-panel controls, connectors, and indicators
with brief descriptions following the figure.
13456 8
Figure 2: PS280 or PS283 Front Panel
1. LED Display. Lights when the instrument is turned on. The
numbers indicate the voltage or current produced by the left
variable power supply.
27
1918151211 13 17 219
20161410
22
2. AMPS/VOLTS Switch. This switch selects whether the LED
display for the left variable power supply shows the current or the
voltage. If the switch is pushed to the left, the display shows the
current. If the switch is pushed to the right, the display shows the
voltage.
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PS280 & PS283 User Manual
Getting Started
3. AMPS Indicator. Lights when AMPS is selected with the
AMPS/VOLTS switch for the left variable power supply.
4. VOLTS Indicator . Lights when VOLTS is selected with
AMPS/VOLTS switch for the left variable power supply.
5. AMPS Indicator. Lights when AMPS is selected with the
AMPS/VOLTS switch for the right variable power supply.
6. VOLTS Indicator . Lights when VOLTS is selected with
AMPS/VOLTS switch for the right variable power supply.
7. AMPS/VOLTS Switch. This switch selects whether the LED
display for the right variable power supply shows the current or
the voltage. If the switch is pushed to the left, the display shows
the current. If the switch is pushed to the right, the display shows
the voltage.
8. LED Display . Lights when the instrument is turned on. The
numbers indicate the voltage or current produced by the right
variable power supply.
9. POWER Button. Turns on the instrument when pressed. When
pressed again, it turns off the instrument.
10.CURRENT Knob. Use this control to set the output current for
the right, variable power supply. If the instrument is in a tracking
mode, the left power supply is the slave and the CURRENT
knob has no effect.
11. C.C. Indicator. If this is lighted, the left variable power supply is
producing a constant current. See Figure 3 on page 10 for an
illustration of the constant voltage/constant current crossover point.
12.C.V. Indicator. If this is lighted, the left variable power supply is
producing a constant voltage. See Figure 3 on page 10 for an
illustration of the constant voltage/constant current crossover point.
PS280 & PS283 User Manual
5
Getting Started
13.Output Terminals. These terminals for the left, variable power
14.VOLTAGE Knob. Allows you to set the output voltage for the
15.TRACKING Buttons. These buttons select the test mode of the
supply allow you to plug in the test leads as follows:
H The red terminal on the right is the positive polarity output
terminal. It is indicated by a + sign above it.
H The black terminal on the left is the negative polarity output
terminal. It is indicated by a – sign above it.
H The green terminal in the middle is the earth and chassis
ground.
left variable power supply. If the instrument is in a tracking
mode, the left power supply is the slave and the VOLTAGE knob
has no effect.
instrument. The PS280 or PS283 features two tracking modes:
series and parallel. If both push-button switches are disengaged
(out), the two variable power supplies operate independently. If
the left switch is pushed in, the instrument operates in series
mode. If both switches are pushed in, the instrument operates in
parallel mode.
In series mode, the master power supply controls the voltage for
both power supplies, which can then range from 0 to 60 V. Refer
to Series on page 20 for further details.
In parallel mode, the master power supply controls both the
voltage and the current for both power supplies. The current can
then range from 0 to 4 A (0 to 2 A for the PS283). Refer to
Parallel on page 22 for further details.
16.CURRENT Knob. Use this control to set the output current for
the right, variable power supply. If the instrument is in a tracking
mode, the right power supply is the master and the CURRENT
knob affects both variable power supplies.
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PS280 & PS283 User Manual
Getting Started
17.Output Terminals. These terminals for the right, variable power
supply allow you to plug in the test leads as follows:
H The red terminal on the right is the positive polarity output
terminal. It is indicated by a plus (+) sign above it.
H The black terminal on the left is the negative polarity output
terminal. It is indicated by a minus (–) sign above it.
H The green terminal in the middle is the earth and chassis
ground.
18.C.C. Indicator. If this is lighted, the power supply is producing a
constant current. See Figure 3 on page 10 for an illustration of the
constant voltage/constant current crossover point.
19.C.V. Indicator. If this is lighted, the power supply is producing a
constant voltage. See Figure 3 on page 10 for an illustration of
the constant voltage/constant current crossover point.
20.VOLTAGE Knob. Allows you to set the output voltage for the
right variable power supply. If the instrument is in a tracking
mode, the right power supply is the master and the VOLTAGE
knob affects both variable power supplies.
21.Output Terminals. These terminals for the 5 V FIXED power
supply allow you to plug in the test leads as follows:
H The red terminal on the right is the positive polarity output
terminal.
H The black terminal on the left is the negative polarity output
terminal.
22.The overload indicator lights when the current on the 5 V FIXED
power supply becomes too large.
PS280 & PS283 User Manual
7
Getting Started
Turning On the Instrument
After you have ensured that the PS280 or PS283 is set up for the
proper line voltage and has the proper fuse (refer to Preparing the
Power Supply for Use on page 2), you are ready to turn it on.
CAUTION. To avoid damaging the PS280 or PS283, do not use it
when the ambient air temperature exceeds 40° C. Also, allow
adequate space at the rear of the instrument to permit the heat sink
to radiate heat.
1. Ensure that the POWER button is disengaged (out) and that the
instrument is turned off.
2. Plug the power cord into an appropriate power source.
3. Turn both VOLTAGE knobs counterclockwise to the minimum
setting.
4. Press the POWER button. The LED displays light up.
8
PS280 & PS283 User Manual
Reference
This section tells how to set the PS280 or PS283 current limit. It also
explains the constant voltage/constant current crossover characteristic of the instrument. Finally, the section includes procedures for
using the instrument in both independent and tracking modes and
provides examples of a variety of applications.
Constant Voltage/Constant Current Crossover
The PS280 or PS283 DC Power Supply features a constant
voltage/constant current automatic crossover. This feature permits
continuous operation in the transition from constant-voltage mode to
constant-current mode as the load changes. The intersection of the
constant-current and constant-voltage modes is called the crossover
point. Figure 3 on page 10 shows the relationship between the load
and the crossover point.
For example, if the load is such that the power supply is operating in
constant-voltage mode, the PS280 or PS283 provides a regulated
output voltage. The output voltage remains constant as the load
increases until the preset current limit is reached. Then the crossover
occurs. At that point, the output current becomes constant and the
output voltage drops in proportion to further load increases.
Crossover is indicated by the front panel red C.C. and green C.V.
indicator lights. If the C.V. indicator is lighted, the instrument is
operating in constant-voltage mode. If the C.C. indicator is lighted,
the instrument is operating in constant-current mode.
Crossover from the constant-current mode to the constant-voltage
mode also occurs automatically in response to a decrease in load. For
example, suppose you are charging a 12 V battery. Initially, the open
circuit voltage of the power supply is preset for 13.8 V. A low battery
places a heavy load on the power supply, and it operates in
constant-current mode. You adjust the instrument to charge the
battery at the rate of 1 A. As the battery becomes charged and its
voltage approaches 13.8 V, the load decreases to the point where the
battery no longer demands the full 1 A charging rate. The PS280 or
PS283 then crosses over to constant-voltage mode.
PS280 & PS283 User Manual
9
Reference
V
O
Maximum
Output
Voltage
Constant Current
Range
Output Current
Figure 3: Constant V oltage/Constant Current Crossover
Constant
Voltage
Range
Maximum
I
O
Crossover Point
Setting the Current Limit
Before you begin using the PS280 or PS283 to power a device, you
should set its current limit lower than the maximum safe current for
the device to be powered.
CAUTION. In order to avoid damaging your device with a current
overload, set the current limit on the PS280 or PS283 before you
connect it to your device.
1. Determine the maximum safe current for the device to be
powered.
2. With the test lead, temporarily short the positive and the negative
output terminals of the power supply together.
10
PS280 & PS283 User Manual
3. Rotate the VOLTAGE knob away from zero sufficiently to light
4. Set the meter selection switch to AMPS so that the LED display
5. Adjust the CURRENT knob for the desired current limit.
6. Read the value shown on the LED display. This is your preset
7. Remove the short between the positive and negative output
You are now ready to power your device.
Test Modes
The two variable power supplies on your PS280 or PS283 can be
operated independently of each other, or the slave supply can track
the master supply. Below are instructions for operating the
instrument in independent modes, followed by instructions for
operating the instrument in series or parallel tracking modes.
Reference
the C.C. indicator.
shows the current.
current limit. Do not increase the current control setting.
terminals.
Independent Modes
In independent mode, any one output of each power supply can be
connected to any one terminal of another supply or to ground. The
variable supplies are independently controlled by the front panel
VOLTAGE and CURRENT control knobs.
There are three independent modes in which you can operate the
PS280 or PS283: floating, ground-referenced, and stacked.
In floating mode, the power supply is not referenced with respect to
ground.
In ground-referenced mode, one of the output terminals is grounded,
providing a fixed reference point for your measurement.
PS280 & PS283 User Manual
11
Reference
In stacked mode, you connect the negative output terminal of one
variable power supply to the positive output terminal of the other.
The stacked configuration allows you to test a circuit requiring
between 30 and 60 V. A stacked configuration can be either floating
or ground-referenced.
Floating. In the independently floating mode, each variable power
supply provides from 0 to 30 V at 0 to 2 A (0 to 1 A for the PS283).
Figure 4 shows each of the three power supplies connected to a
separate load.
SLAVE MASTER
GND
Load 3
0 to 30 V
0 to 2 A (PS280)
0 to 1 A (PS283)
GND
Load 2 Load 1
0 to 30 V
0 to 2 A (PS280)
0 to 1 A (PS283)
Figure 4: Independent Floating Application
The tracking switches are disengaged for independent operation. The
left voltage and current control knobs control the outputs for the
slave variable power supply, and the right knobs do the same for the
master power supply. All outputs are electrically independent.
T o test a circuit in the independently floating mode, follow these
steps:
1. Press the POWER button to apply power to the PS280 or PS283.
2. Rotate the VOLTAGE knob to zero.
3. Determine the polarity of your device.
5V FIXED 3A
5V
0 to 3 A
12
PS280 & PS283 User Manual
Reference
4. Plug one of the test leads into the positive output terminal.
5. Plug the other test lead into the negative output terminal.
6. Press POWER to turn off the PS280 or PS283.
7. Clip the positive test lead to the positive pole of your device.
8. Clip the negative test lead to the negative pole of your device.
9. Press POWER to turn on the PS280 or PS283.
10.Push the AMPS/VOLTS selection switch so that the LED display
shows either voltage or current, as you want.
11. Rotate the VOLTAGE knob as desired.
12.If you are using a preset current limit (see page 10), do not touch
the CURRENT knobs. Otherwise, rotate the CURRENT knob as
desired.
Ground-Referenced. In the independently ground-referenced mode,
each variable power supply provides from 0 to 30 V referenced with
respect to ground at 0 to 2 A (0 to 1 A for the PS283). Any one of a
pair of output terminals, either the positive or the negative, can be
connected to ground. The FIXED 5 V power supply can also be
ground-referenced.
WARNING. In order to avoid grounding the power line, which can
cause electrical shock, explosion, or fire, isolate the device being
powered from the line voltage power source when using any
ground-referenced output configuration from the PS280 or PS283.
Figure 5 shows an example of a circuit with the FIXED 5 V terminal
referenced to ground and both the master and slave variable power
supplies referenced to –5 V.
PS280 & PS283 User Manual
13
Reference
SLAVE MASTER
GND
Load 3
–5 TO +25V
0 to 2 A (PS280)
0 to 1 A (PS283)
GND
Load 2 Load 1
–5 TO +25V
0 to 2 A (PS280)
0 to 1 A (PS283)
Figure 5: Independent Common Ground-Referenced Application
In this configuration, each of the variable power supplies can be
varied from –5 V to +25 V (+30 V overall). The GND post becomes
the relative negative terminal for both variable outputs. Because the
variable power supplies are referenced to –5 V, the LED display,
when set to display volts, shows a value that is five volts lower than
the actual output.
For example, the LED display indicates:
H 0 V when the output is –5 V
5V FIXED 3A
–5 V
3A
14
H 5 V when the output is 0 V
H 30 V when the output is 25 V
Negative 5 V is available between GND and the negative terminal of
the FIXED 5 V power supply.
T o test a circuit in the independently ground-referenced mode,
follow these steps:
1. Turn the POWER off to the PS280 or PS283.
2. Connect the outputs as shown in Figure 5.
3. Set both variable supply VOLTAGE controls to the minimum
setting.
PS280 & PS283 User Manual
Reference
4. Set both variable supply CURRENT controls to midrange.
5. Set the AMPS/VOLTS switches for both power supplies to
display volts.
6. Turn on the POWER to the PS280 or PS283. The display should
read 0 V for both variable power supplies. An external meter
connected across the load or load terminals should read –5 V.
7. Turn the POWER off to the PS280 or PS283 again.
8. Connect the device or devices to be tested.
9. Turn on the POWER to the PS280 or PS283 again. Adjust the
voltages as needed.
Figure 6 shows the PS280 or PS283 connected to produce separate
outputs of +5 V from the FIXED power supply, 0 to +30 V from the
slave variable power supply, and 0 to –30 V from the master variable
power supply. In this configuration, the red output terminal of the
master variable power supply is the negative reference terminal
because it is directly connected to the ground terminal.
SLAVE MASTER
GND
Load 3
0 to +30 V
0 to 2 A (PS280)
0 to 1 A (PS283)
GND
Load 2
0 to –30 V
0 to 2 A (PS280)
0 to 1 A (PS283)
Figure 6: Independent Ground-Referenced Split Application
PS280 & PS283 User Manual
5V FIXED 3A
Load 1
5V
0 to 3 A
15
Reference
T o test a circuit in a independent ground-referenced split application
mode, follow these steps:
1. Turn the POWER off to the PS280 or PS283.
2. Connect the outputs as shown in Figure 6.
3. Set both variable supply VOLTAGE controls to the minimum
setting.
4. Set both variable supply CURRENT controls to midrange.
5. Turn on the POWER to the PS280 or PS283.
6. Set the desired voltages for both variable power supplies.
7. Turn the POWER off to the PS280 or PS283 again.
8. Connect the device or devices to be tested.
9. Turn on the POWER to the PS280 or PS283 again. If necessary,
readjust the voltages.
Figure 7 shows the configuration for three ground-referenced
negative power supplies.
SLAVE MASTER
GND
Load 3
0 to –30 V
GND
Load 2 Load 1
0 to –30 V
Figure 7: Three Ground-Referenced Negative Power Supplies
16
PS280 & PS283 User Manual
5V FIXED 3A
–5 V
Figure 8 shows the configuration for three ground-referenced
positive power supplies.
SLAVE MASTER
Reference
GND
Load 3
0 to 30 V
0 to 2 A (PS280)
0 to 1 A (PS283)
GND
Load 2
0 to 30 V
0 to 2 A (PS280)
0 to 1 A (PS283)
Figure 8: Three Ground-Referenced Positive Power Supplies
Stacked. In the independently stacked mode, the variable power
supplies are connected and provide from 0 to 60 V at 0 to 2 A (0 to
1 A for the PS283).
Figure 9 on page 18 shows the PS280 or PS283 connected in a
stacked manner to produce a variable output of 0 to +60 V
ground-referenced. The FIXED power supply produces –5 V,
ground-referenced. In this configuration, the red output terminal of
the master variable power supply is the negative reference terminal
because it is directly connected to the ground terminal.
5V FIXED 3A
Load 1
5V
0 to 3 A
PS280 & PS283 User Manual
17
Reference
SLAVE MASTER
GND
GND
Load 2 Load 1
0 to +60 V
Figure 9: Independent Positive Stacked Application
T o test a circuit in the independently stacked mode, follow these
steps:
1. Turn the POWER off to the PS280 or PS283.
2. Connect the outputs as shown in Figure 9.
3. Set both variable supply VOLTAGE controls to the minimum
setting.
4. Set both variable supply CURRENT controls to midrange.
5V FIXED 3A
–5 V
18
5. Turn on the POWER to the PS280 or PS283.
6. Set the desired voltage. Observe the LED display; the total output
is the sum of both voltage readings.
7. Turn the POWER off to the PS280 or PS283 again.
8. Connect the device or devices to be tested.
9. Turn on the POWER to the PS280 or PS283 again. If necessary,
readjust the voltages.
PS280 & PS283 User Manual
Reference
Figure 10 shows a stacked application in which you have a 0 to
–60 V output from the variable power supplies and a +5 V output
from the FIXED power supply.
SLAVE MASTER
GND
Load 2 Load 1
GND
Figure 10: Independent Negative Stacked Application
5V FIXED 3A
+5 V0 to –60 V
PS280 & PS283 User Manual
19
Reference
Tracking Modes
There are two tracking modes in which you can operate the PS280 or
PS283: series and parallel.
Series. In series mode, the positive output terminal of the master
variable power supply is internally connected to the negative output
terminal of the slave power supply. This connection allows the
PS280 or PS283 to produce 0 to 60 V at 0 to 2 A (0 to 1 A for the
PS283).
When you place the PS280 or PS283 in series mode, the output
terminals are hooked together internally as shown in Figure 11.
MASTER
20
SLAVE
Figure 11: Series Tracking Inside the PS280 or PS283
The voltage knob for the master variable power supply controls the
voltage for both variable power supplies. Using the master voltage
control, the maximum slave supply voltage is automatically set to the
same value as the master supply.
T o test a circuit in the series tracking mode, follow these steps:
PS280 & PS283 User Manual
1. Turn the POWER off to the PS280 or PS283.
2. Connect the outputs as shown in Figure 12.
INTERNAL
SLAVE MASTER
Reference
GND
GND
Figure 12: Series Tracking Application
3. Set the PS280 or PS283 to series tracking mode by pressing the
left TRACKING button. Make sure that the right TRACKING
button is released (out).
4. Set the master AMPS/VOLTS switch to the voltage metering
position. Set the slave AMPS/VOLTS switch to the current
metering position. This allows you to simultaneously monitor
both current and voltage.
5V FIXED 3A
Load 1
0 to +60 V
NOTE. In series tracking mode, the output voltage is double the value
displayed on the voltage metering LED display, because both
supplies are producing the same voltage.
5. Set the slave CURRENT knob fully clockwise.
6. Set the current limit using the master CURRENT knob. (Refer to
Setting the Current Limit on page 10.)
PS280 & PS283 User Manual
21
Reference
NOTE. In series tracking mode, the current flowing through the two
supplies must be equal. Therefore, the maximum current limit is the
lower of the values set by the two current control knobs.
7. Turn on the POWER to the PS280 or PS283.
8. Adjust the output voltage to the desired level using the master
VOLTAGE knob.
9. Turn the POWER off to the PS280 or PS283 again.
10.Connect the device or devices to be tested.
11. Turn on the POWER to the PS280 or PS283 again. Readjust the
voltages if necessary.
NOTE. The 5 V FIXED supply can be independently grounded or
allowed to float.
22
Parallel. In parallel tracking mode, the positive output terminals of
both variable power supplies are internally connected, and the
negative output terminals of both variable power supplies are
internally connected. These connections allow the PS280 or PS283 to
produce 0 to 30 V at 0 to 4 A (0 to 2 A for the PS283).
When you place the PS280 or PS283 in parallel mode, the output
terminals are hooked together internally as shown in Figure 13.
The master power supply’s VOLTAGE and the CURRENT knobs
control the voltage and current for both variable power supplies.
PS280 & PS283 User Manual
Reference
MASTER
SLAVE
Figure 13: Parallel Tracking Inside the PS280 or PS283
T o test a circuit in the parallel tracking mode, follow these steps:
1. Turn the POWER off to the PS280 or PS283.
2. Connect the outputs as shown in Figure 14 on page 24.
3. Set the PS280 or PS283 to parallel tracking mode by pressing
both tracking buttons.
4. Set the master AMPS/VOLTS switch to the voltage metering
position, and set the slave AMPS/VOLTS switch to the current
metering position. This allows you to simultaneously monitor
both current and voltage.
NOTE. In parallel tracking mode, the output current is double the
value displayed on the current metering LED display, because both
supplies are producing the same amount of current.
5. Turn on the POWER to the PS280 or PS283.
6. Set the current limit using the master CURRENT knob. (Refer to
Setting the Current Limit on page 10.)
PS280 & PS283 User Manual
23
Reference
INTERNAL
SLAVE MASTER
GND
GND
0 to 4 A (PS280)
0 to 2 A (PS283)
Figure 14: Parallel Tracking Application
7. Adjust the output voltage to the desired level using the master
VOLTAGE knob.
8. Turn the POWER off to the PS280 or PS283 again.
9. Connect the positive polarity of the device being powered to the
positive master terminal.
10.Connect the negative polarity of the device being powered to the
negative master terminal.
5V FIXED 3A
Load 1
0 to +30 V
24
CAUTION. To prevent damage to the PS280 or PS283, do not attempt
to obtain output simultaneously from both variable power supplies
while in parallel tracking mode.
NOTE. The 5 V FIXED supply can be independently grounded or
allowed to float.
PS280 & PS283 User Manual
Appendix A: Specifications
Relative
%
%
Table 1: Physical Characteristics
Dimension
Width 255 mm (10.0 in)
Height 145 mm (5.7 in)
Depth 335 mm (13.2 in)
Weight 11.5 kg (25.4 lb) PS280
Measurement
9.0 kg (19.9 lb) PS283
Table 2: Environmental Characteristics
Characteristic
Storage
Operating
Temperature
–10_C to +70_C
0_C to 40_C
70
80
Table 3: Operational Characteristics
Characteristic
Outputs Two 0 to 30VDC, one 5 VDC
Measurement
Humidity
Voltage (5V) 5.0 ±0.25 VDC at 3.0 A maximum foldback current
limited
Voltage (0–30V) 0–30 constant VDC at 2.0 A constant, maximum (PS280)
or 1.0 A constant. maximum (PS283)
Line Regulation (5 V)
Line Regulation (CV)
5mV
0.01% +3 mV PS280
0.01% + 5 mV PS283
PS280 & PS283 User Manual
25
Appendix A: Specifications
Table 3: Operational Characteristics (Cont.)
Characteristic Measurement
Line Regulation (CC)
0.2% +3 mA
Load Regulation (5 V)
Load Regulation (CV)
Load Regulation (CC)
Ripple/Noise (5 V)
Ripple/Noise (CV)
Ripple (CC)
Temperature Coefficient (CV)
Recovery Time (CV)
Tracking Error (Slave)
Indicator Two 31/2 digit 0.5 in LED panel display meter
Meter Indicators 0–30 VDC ±(0.5% of reading + 2 digits)
Insulation
(Chassis-to-Terminal)
Insulation
(Chassis-to-AC Cord))
0.2%
0.01% +3 mV (rating current 3A)
0.01% +5mV (rating current >3 A)
300 mV (0–60 V single series tracking supply)
0.2% +3 mA
2 mV rms
1 mV rms, 5 Hz–1 MHz
3 mA rms
300 ppm/_C
100 s (time to recover after a 50% load change with
0.5 A minimum)
0.5% +10 mV of the master supply
0–2 A ±(0.5% of reading + 2 digits)
20 M at DC 500 V
30 M at DC 500 V
26
PS280 & PS283 User Manual
Appendix A: Specification
s
Table 4: Electrical Characteristics
Characteristic Measurement
Line voltage 90 to 110
108 to 132
198 to 242
216 to 250, all VAC at 50–60Hz
Power consumption 386 VA, 300 W maximum (PS280)
265 VA, 200 W maximum (PS283)
Table 5: Certifications and Compliances
EC Declaration of
Conformity – EMC
EC Declaration of
Conformity – Low
Voltage
Meets intent of Directive 89/336/EEC for Electromagnetic
Compatibility. Compliance was demonstrated to the following
specifications as listed in the Official Journal of the European
Communities:
EN 55011 Class B Radiated and Conducted Emissions
EN 50081-1 Emissions:
EN 60555-2 AC Power Line Harmonic Emissions
EN 50082-1 Immunity:
IEC 801-2 Electrostatic Discharge Immunity
IEC 801-3 RF Electromagnetic Field Immunity
IEC 801-4 Electrical Fast Transient/Burst Immunity
IEC 801-5 Power Line Surge Immunity
Compliance was demonstrated to the following specification as
listed in the Official Journal of the European Communities:
Low Voltage Directive 73/23/EEC, amended by 93/68/EEC.
HD401 S1 Safety Requirements for Electronic
Measuring Aparatus.
PS280 & PS283 User Manual
27
Appendix A: Specifications
28
PS280 & PS283 User Manual
Appendix B: Maintenance
This appendix provides information for the basic maintenance of the
PS280 or PS283 Laboratory DC Power Supply.
Cleaning
T o clean the Laboratory DC Power Supply, use a soft cloth
dampened in a solution of mild detergent and water. Do not spray
cleaner directly onto the instrument, since it may leak into the
cabinet and cause damage.
Do not use chemicals containing benzine, benzene, toluene, xylene,
acetone, or similar solvents.
Do not use abrasive cleaners on any portion of the power supply.
Preparing for Shipment
If the original packaging is unfit for use or not available, use the
following packaging guidelines:
1. Use a corrugated cardboard shipping carton having inside
dimensions at least three inches greater than the instrument
dimensions.
2. Put the instrument into a plastic bag or wrap to protect it from
dampness and loose packing material.
3. Place the instrument into the box and firmly stabilize it with
packing material.
4. Seal the carton with shipping tape.
PS280 & PS283 User Manual
29
Appendix B: Maintenance
Troubleshooting
Electronic maintenance on the power supply must be performed by a
trained technician. However, an operator can perform some basic and
routine maintenance. Perform the following steps to isolate the fault:
1. The power switch is on. The instrument is plugged in. Neither the
C.C. nor the C.V. indicator is lighted.
Check the output terminals with a voltmeter.
a. Set the voltage control of the voltmeter to midrange.
b. Ensure that the range and polarity settings are correct.
c. Place the voltmeter jacks in the PS280 or PS283 output
terminals.
d. Determine if the terminals are producing any output.
Are the outputs working?
Yes Go to step 2.
No Go to step 3.
30
2. Refer to a service technician.
WARNING. To prevent electrical shock, unplug the power cord and
disconnect the test cables from any power source before checking or
replacing the fuse.
3. Check the fuse with a multimeter.
a. Set the multimeter to the low ohms range.
b. Apply the multimeter probes across the fuse.
c. Determine if a continuous circuit exists.
Is the fuse okay?
Yes Go to step 5.
No Go to step 4.
4. Replace the fuse.
PS280 & PS283 User Manual
Appendix B: Maintenance
5. Verify that the line settings on the rear panel match the line
voltage. Do they?
Yes Go to step 7.
No Go to step 6.
6. Reset the line settings. Refer to Preparing the Power Supply for
Use on page 2.
7. Check the power cord.
WARNING. To prevent personal injury, be sure the power cord is
disconnected at both ends before you check it.
Is the power cord frayed or broken?
Yes Go to step 8.
No Go to step 2.
8. Replace the power cord.
9. The power switch is on. A variable output power supply is
connected to a circuit. The C.C. or C.V. indicator is on. Neither
variable output power supply is producing any electrical output.
Disconnect the instrument from the circuit. Check the output
terminals with a voltmeter. Are the outputs working?
Yes Go to step 10.
No Go to step 2.
10.Check the circuit you have been testing for a short or low
resistance.
PS280 & PS283 User Manual
31
Appendix B: Maintenance
32
PS280 & PS283 User Manual
Appendix C: Replaceable Parts
Replaceable parts may be ordered directly from your authorized
T ektronix dealer.
Standard Accessories
The following items are shipped with the Laboratory DC Power
Supply:
Table 6: Standard Accessories
Accessory
Fuse, 5 x 20 mm, 4 A, 250 V, SB
(PS280: 90 – 132 V operation)
Fuse, 5 x 20 mm, 2.5 A, 250 V, SB
(PS283: 90 – 132 V operation)
Test Leads 196-3201-00
User Manual 070-8355-XX
115 V Power Cord Refer to Table 8
Optional Accessories
The following items are available as optional accessories:
Table 7: Optional Accessories
Accessory
Fuse, 5 x 20 mm, 2 A, 250 V, SB
(PS280: 198 – 250 V operation)
Fuse, 5 x 20 mm, 1.25 A, 250 V, SB
(PS283: 198 – 250 V operation)
230 V Power Cords Refer to Table 8
Tektronix Part Number
159-0297-00
159-0226-00
Tektronix Part Number
159-0107-00
159-0247-00
PS280 & PS283 User Manual
33
Appendix C: Replaceable Parts
The following power cords are available:
Table 8: Accessory Power Cords
Plug Configuration
Normal Usage
North America
115 V
Tektronix Part
Number
161-0104-00
Europe
230 V
United Kingdom
230 V
Australia
230 V
North America
230 V
Switzerland
230 V
161-0104-06
161-0104-07
161-0104-05
161-0104-08
161-0167-00
34
PS280 & PS283 User Manual
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