Text preview for : Systron Donner PQ Series Power Supplies.pdf part of Systron-Donner PQ20-2 Operating and Service Manual for PQ Series of Power Supplies
Back to : Systron Donner PQ Series | Home
DONNER
ember THORN Group
EMI
PQ SERIES
INSTRUMENT DIVISION POWER SUPPLIES
DOCUMENT NO. 120022-01
OPERATING AND SERVICE MANUAL
9797 Systron Drive *Concord, California 94518 ® Copyright © 1982 Systron Donner
Printed in U.S.A
Tel: (415)676-5000 *TWX: 910-481-9479 eCable: DONES
FSCM No. 52542
SYSTRON TEST & MEASUREMENT GROUP
DONNER SYSTRON DONNER
Member THORN EMI Group WARRANTY POLICY
I Warranty
The Test & Measurement Group of Systron Donner warrants that at the time of shipment the products manufactured by Systron Donner's
T & M Group and sold hereunder will be free from defects in material and workmanship and will conform to the specifications furnished by
or approved in writing by Systron Donner's T & M Group.
II Warranty
A The warranty period for products published in our latest product catalog will be one year from the date of shipment. This war-
ranty is extended only to the original buyer.
B The warranty period for products published in prior catalog, will be 90 days from the date of shipment.
C The warranty period for modified standard products, custom products, or new spare part assemblies will be 90 days from the date of
shipment.
D The warranty period for systems or assemblies of miscellaneous components and products will be limited to the warranty for the stand
alone component or instrument. The system itself is not guaranteed unless a specific installation and service agreement has been
negotiated between Systron Donner andthe customer. In this latter case, the warranty period will be 30 days after the installation ofthe
system while the various portions of the system will be limited to the normal component or instrument stand alone warranty, and for
non Systron Donner material within the system that is furnished by Systron Donner the warranty will be limited to the supplier's normal
warranty.
III Warranty Adjustments
If any defect within this warranty appears, Purchaser shall notify Seller immediately.
B Systron Donner's T & M Group agrees to repair or furnish a replacement for, but not install, any product which, within the standard war-
ranty shall, upon test and examination by Systron Donner's T & M Group, prove defective within the above warranty period.
C No product will be accepted for return or replacement without the written authorization of Systron Donner's T & M Group. Upon such
authorization and in accordance with instructions by Systron Donner's T & M Group, the product will be returned to the original
manufacturing location, shipping charges prepaid by Purchaser.
IV Exclusions from Warranty
The foregoing warranty is in lieu of and excludes all other expressed or implied warranties of merchantability or fitness or otherwise.
B Systron Donner's T & M Group will not be liable for any special or consequential damages or for loss, damages or expense directly or in-
directly arising from the use of the products, or any inability to use them either separately or in combination with any other equipment
or material, or from any other cause.
C The warranty does not extend to any product manufactured by Systron Donner's T & M Group which has been subjected to misuse,
neglect, accident, improper installation or to use in violation of instructions furnished by Systron Donner's T & M Group
D The warranty does not extend to or apply to any unit which has been repaired or altered at any place other than at a Systron Donner
T & M Group factory, by persons not expressly approved by Systron Donner's T 4 M Group, not to any unit, the serial number of which
has been removed or defaced or changed.
E This warranty applies to new equipment only and will cover repaired or replacement items only to the extent of the balance remaining
of the items original warranty period noted above in Paragraph ll.
F All freight charges will be paid for by the Purchaser.
Divisions in the Test & Measurement Group include:
Instrument Division -- Concord, CA
ACD Division -- Sunnyvale, CA
SD GmbH -- Munich, West Germany
January 1982
fei
E 2
,
SYSTRON INSTRUMENT
DONNER Division
9797 Systron Drive, Concord, CA 94518
Phone (415) 676-5000
TWX 910-481-9479
PROPRIETARY RIGHTS STATEMENT
The design information contained herein is the sole property of
Systron Donner. The disclosure of this information does not con-
stitute the release of proprietary rights thereof, but is to be used for
informational purposes only. Permission to reproduce this informa-
tion of the product described herein must be obtained in writing
from Systron Donner.
Copyright © 1982 Systron Donner
Printed in U.S.A.
TABLE OF CONTENTS
CHAPTER PAGE
1 GENERAL INFORMATION
TOT Introduction .
192 Description
1.3 Specifications . : A
1.4 Physical ee 1
INSTALLATION AND OPERATION~
Introduction . :
Receiving Inspection :
Reshipment
Installation . :
Power Requirements .
Output Connection '
Front Panel
Rear Panel
Operation
1 Local Control Operation ^u Mats
P9
WN*
F2
NN (
t
O
S| O .2 Remote Programming Operation . . . P9o
N -J
tO
NNN
NNN
P9 +
C4
=
PRINCIPLES OF OPERATION
P-Series Functional Be AN
Circuit Analysis .
Primary Input, Rectifiers and Filter Circuits
Series Pass Regulator Circuit
Auxiliary Regulator Circuit
Voltage Error Amplifier "7.
,,Current Control Circuit! :
VLm and Over Voltage Comparator .
CA
C3 4
Cà N 06
Cà tS
=>
Y Current Sink Circuit . EC
AAC
DN
=
MAINTENANCE AND CALIBRATION
Introduction .
Test Equipment . ;
Test and Calibration en
Prepower Check Procedure .
Local Mode Operational Test and Calibration Procedure.
Remote Mode Operational Test and Calibration Procedure .
Overvoltage Crowbar Circuitry Test .
Current Sink Test Procedure
O®
©.
19 au
=
[N
Power
Supply Performance Tests .
Power Supply Troubleshooting .
Loads and Interconnections
De Power Supply Fault Isolation .
s
naf QP
SSF .C
np I
e .
PES =P
LJ
LJ
.
-
.
° Integrated Circuits Component Data Sheets sB0o
Q
CY
A0m
0
Nt
9
0
O
PQ SERIES-10-79 iii
TABLE OF CONTENTS (Con't)
CHAPTER PAGE
5 REPLACEABLE PARTS LISTS
Introduction . :
Part Ordering Information
Cà RD
C1
u Parts List
Final Assembly .
Chassis Assembly . . . . '
Diode PC Board Assembly
Front Panel Assembly .
Rear Panel Assembly Ul
(O
+
RR
Input Connector Kit . q ' = ul
Ci
Y
Y
C1
Indicator PC Board Assembly
Harness Assembly... .
Control PC Board Nu
Schematic 065445
LISTZORSEIGURES
Figure P-Series Outline Drawings
Front Panel Functions
Rear Panel Functions
Load Lead Wire Size Monograph '
P Series Functional Schematic Diagram 1
Current Sink Function
Voltage Mode Test Configuration
+
)
P2
4C
DD G Voltage Mode Test Configuration N +
)+ N ON
+.
Ul
LIST OF TABLES
Table P-Series Modules .
Power Ratings
Performance Specifications
Supplemental Characteristics .
Physical Characteristics
Power Transformer Primary Connection:
Front Panel Functions.
1 Rear Panel Functions tC
Programming Connector 2 .
P-Series Programming Format o
Sink Current Limit Values
Recommended Test Equipment
P-Series Test Voltages . 2 : I
1
' o
=
S nQ
4IU=
S.
£ (
N
P R
N= Manufacturer's Code-To-Name I dem GQ
N
I Ul
4
Q1 +
U1
to k=
N
RP C=
P9
iv PQ SERIES-10-79
CHAPTER 1
GENERAL INFORMATION
1.1 INTRODUCTION
The P-Series power supplies consists of four PQ Quarter-rack supplies and four
PH Half-rack supplies. These supplies may be operated locally via the front
panel controls or switch selected for remote operation using a remote program
source. The Systron Donner P-1 and P-2 Programmer modules provide all the logic
necessary to control the P-Series supplies via an IEEE STD-488 GPIB.
Table 1-1 provides a listings of the eight modules that make up the P-Series
power supply system.
5 TABLE 1-1 P-SERIES MODULES
MODULE FUNCTION AND CHARACTERISTICS
Programmable 0-10V, 0-3A Quarter-rack Power Supply
Programmable 0-20V, 0-2A Quarter-rack Power Supply
Programmable 0-50V, 0-14 Quarter-rack Power Supply
Programmable 0-100V, 0-0.5A Quarter-rack Power Supply
Programmable 0-10V, 0-10 Half-rack Power Supply
Programmable 0-20V, 0-6 Half-rack Power Supply
Programmable 0-50V, 0-3A Half-rack Power Supply
Programmable 0-100V, 0-1.5A Half-rack Power Supply
This instruction manual contains the general characteristics and specifications,
operating procedures, theory of operation, maintenance and calibration pro-
cedures, parts lists and the related schematic diagrams and assembly drawings
for all the modules that comprise the P-Series power supplies.
The P1, P1E, and P2 Programmer modules that provide the remote programming
for the power supplies are not included in this instruction manual. If the
Power Supplies are to be system configured utilizing programmer modules, refer
to the P1 and P2 Programmer Instruction Manual for detailed information on sys-
tem configuration, programmer data and operation and maintenance of the Program-
mer modules.
1.2 DESCRIPTION
The P-Series power supplies are modular in design to allow a compact multiple
output programmable system configuration for use in test and process-control
systems when used in conjunction with the P-Series programmer(s). The program-
mer will allow up to eight power supplies to be controlled via a General Propose
Interface Bus (GPIB) which conforms to IEEE STD-488-1975 or locally via the
programmer front panel data switches. The power supplies will respond
to program changes in less than 2 milliseconds. Each Power Supply module
may be controlled locally by its front panel control settings when the local
PO SERIES-10-79 1-1
modes are rear panel switch selected. The Power Supply modules are lightweight,
compact precision dissipative regulators housed in quarter and half rack chassis
having equal height and depth, thus allowing a compact multiple output rack
assembly. Both constant voltage and constant current operation are provided,
which may be either locally controlled or remotely programmed. In the voltage
mode, adjustable current limiting is provided, while the current mode provides
adjustable voltage limiting. Both output voltage and current are front panel
metered, and front panel indicators provide indication of the operational mode
of the supply.
1.3 SPECIFICATIONS
Table 1-2 lists the power supply power ratings. The performance specifications
describe the power supply's warranted performance and are listed in Table 1-3.
Table 1-4 provides the supplemental characteristics of the power supply which
are typical values, but non-warranted performance parameters.
TABLE 1-2 POWER RATINGS
Output Sink
P-Series Voltage Mode += Current J
10-3 10 Vdc 3 All models: All models:
20-2 20 Vdc : E
PQ 50-1 50 Vdc $ ó 90-110 Vac 47-440 Hz
100-0.5 100 Vdc 3 5 5 : 3 104-127 Vac
: 194-237 Vac
10-10 10 Vdc j ° 207-253 Vac
20-6 20 Vde
50-3 50 Vdc
100-1.5 100
Notes
* An extra 0.5 V per output lead compensates for lead voltage drop.
** Isolation voltage: 300V terminal to chassis.
*** Nominal value
TABLE 1-3 PERFORMANCE SPECIFICATIONS
PERFORMANCE STABILIZATION MODE
SPECIFICATIONS VOLTAGE CURRENT
LOAD EFFECT: The change in 0.0025 E-rated | 0.05% I-rated or
stabilized output caused by lmA2 + 3 mA
a load change equal to the whichever is greater
output rating.
SOURCE EFFECT: The change in 0.001% E-rated 0.005% I-rated or
stabilized output caused by . 200 uA whichever is
any change in the ac line | greater
within the input rating.
149 PQ SERIES-10-79
TABLE 1-3 PERFORMANCE SPECIFICATIONS (Cont'd)
PERFORMANCE AB ALION MODE
SPECIFICATIONS TAGE | CURRENT
PARD: Periodic and random devi- 300 uV rms or 0.05% I-rated, or
ations from the stabilized output, 3 mV p-p 1 mA, RMS whichever is
measured from 20 Hz to 10 MHz. greater
0.15% I-rated, or
3 mA, p-p whichever is
greater
STEP RESPONSE TIME: The time 2 ms 1 ms
required to achieve 99.9% of the
programmed change with a resis-
tive load.
With a capacitive load, voltage stabilization may be delayed because current,
charge or discharge, is limited. When the load capacitance is known, the step
response time can be calculated using the equation below C; is the supply's
internal capacitor (see output ratings) and I, is the sink or source current
limit. The units of measure are seconds, volts, farads and amperes.
Time =
AE (Ci11 + Ce)
TABLE 1-4 SUPPLEMENTAL CHARACTERISTICS
SUPPLEMENTAL : STABILIZATION MOD
CHARACTERISTICS __ VOLTAGE CURRENT
DRIFT: The output drift over 8 0.01% E-rated in| 0.1% I-rated or
hours under constant line, load Local 3 mA* in Local
and temperature after a 30- 0.005% E-rated 0.02% I-rated in
minute warmup. in Remote Remote
TEMPERATURE EFFECT: The change 0.01% E-rated in | 0.01% I-rated in
in stabilized output per °C Local Local or Remote
change in ambient temperature. 0.005% E-rated
in Remote
RESOLUTION: The resolution ob- 0.03% E-rated 0.06% I-rated
tainable with front panel
controls:
PROGRAMMING SCALE: The ex- 0 to +10V 0 to -1 mA
ternal input that will change 6 1 mA e -1V
the output from minimum to Voltage and
maximum. VLIM
PO SERIES-10-79 1-3
TABLE 1-4 SUPPLEMENTAL CHARACTERISTICS (Cont'd)
SUPPLEMENTAL STABILIZATION MODE
CHARACTERISTICS VOLTAGE
L
TRANSIENT RECOVERY: Time required 50 us |
to recover within 0.1% E-rated
following a step load change be-
tween 10% and 100% of I-rated.
METER ACCURACY: The maximum non- oe
linear error at 25"C.
VLIM ® ADJUSTMENT RANGE: 5% to 109%
E-rated
VLIM
® MARGIN: The re commended 5% E-rated
minimum margin of sett ing above
output voltage.
CROWBAR TRACKING RANGE SV to 110%
E-rated **
CROWBAR THRESHOLD: Th e voltage 1% E-rated
above at which the crow- 50 us response
9317 111 1
Notes:
* Whichever is greater
** SOV and 100V models 7V to 110%
1.4 PHYSICAL CHARACTER ISTICS
Table 1-5 lists the P-Series power supplies' physical characteristics. Figure 1-1
provides outline drawings with dimensional data.
TABLE 1-5 PHYSICAL CHARACTERISTICS
------
Storage Temperature: -40 G to +85. C
Dimensions:
PQ Models Height SSS (1927 rem)
Width 4:09" (1073 Em)
Depth 19.351 1
PH Models Height 5:351 (13.7 cm)
Width 8.10" (20.6 cm)
Depth 16-355" (410 52cm)
Weight:
PQ Models Net 11 lbs (5 kg)
Shipping 15 105 (6.8 Ke)
PH Models Net 25 1095 01055 KS)
Shipping 115 )
PQ SERIES-10-79
PQ MODELS
708.41
16.35 ee TT
FIGURE 1-1 P-SERIES OUTLINE DRAWINGS
PQ SERIES-10-79 1-5
AT 1 3 i DEI 0
22 FUN LIE
I 9
»4- 4
7 LH
Led INL LLL eas
m 1
o
e dm
P
'
?
I
CA
A jasio , aeo
i 1
4
5 5 --
vw + -
|
1
4
ES
D
E E
E =
bh E
5
Da 0 5
T =. x
CHAPTER 2
INSTALLATION AND OPERATIONS
2.1 INTRODUCTION
The P-Series Power Supplies are shipped in operational condition and are ready for
use as received. This chapter outlines the procedures for initial inspection, in-
stallation and operation of the unit. Instructions for reshipment are also included
should the unit be returned to Systron-Donner for service or repair.
2.2 RECEIVING INSPECTION
Prior to accepting the unit from the shipper, inspect the condition of the shipping
container for any indication of freight damage. Any sign of such damage must be
noted by both the shipper and receiver and*should be reported to the insurance
investigator.
Immediately following removal of the instrument from the shipping carton, inspect
for possible physical damage incurred during shipment. Check surfaces for scratches
or dents and note condition of controls and connectors. Should any damage be noted,
notify your nearest Systron-Donner representative --- DO NOT USE THE POWER SUPPLY
UNTIL INSTRUCTED TO DO SO BY THE REPRESENTATIVE.
2.3 RESHIPMENT
When the instrument is to be repackaged for shipment use the original packing
materials. Your Systron-Donner field-office can provide materials similar to those
used for the original factory packaging, or repackage the instrument following these
general instructions.
General packaging instructions:
1) Attach a tag to the unit indicating the model number, serial number, name and
address of the instrument owner, and a summary of the service or repairs required.
2) Wrap the instrument in heavy paper or plastic prior to placing it into the
shipping container.
3) Select a strong carton or wooden box to house the instrument.
4) Use an adequate layer of shock-absorbing material on all sides of the instru-
ment and protect the front panel with additional layers of cardboard. Be certain
that there is no movement of the unit within the container.
5) Seal the package with strong tape or metal bands.
6) Mark the shipping container ''FRAGILE-DELICATE INSTRUMENT" to ensure careful
handling.
7) Be certain that all correspondence refers to full instrument nomenclature
(model and serial number).
2.4 INSTALLATION
The P-Series power supply may be used as a "stand alone" bench supply installed
in its instrument cabinet, or rack mounted in groups to form compact multiple
output rack assemblies. They are dimensioned in quarter rack 4.25" (108 mm)
PQ SERIES-10-79
2-1
width and half rack 8.5" (216 mm) width, of equal height 5.38'' (137 mm) and depth
16.0" (406 mm). Rack mounting assemblies are provided by Systron-Donner to form
the following configurations.
2/4 Assembly; Two quarter rack modules in a half rack width assembly.
3/4 Assembly; Mixed quarter and half rack modules in a three-quarter rack
width assembly.
4/4 Assembly; Mixed quarter and half rack modules in a full rack mountable
UNTER
2.5 POWER REQUIREMENTS
The P-Series power supplies are equipped with a standard captive three-conductor
power cord which when plugged into an appropriate power receptacle, grounds the
power supply module to protect operating personnel from certain electrical hazards.
Whenever the power cord is mated to a two-conductor outlet, a cord adapter plug
(properly installed) will provide the same protection.
The instrument operates from an ac power source and by appropriate connection of
internal taps from either 90-110 Vac, 104-127 Vac, 194-237 Vac, and 207-253 Vac
at 47-440 Hz. Power consumption varies for each model as described in the speci-
fications. Unless requested otherwise, the instrument is normally factory wired
for 104-127V ac. Prior to operation ensure the unit is wired for the correct line
voltage application. To change operating voltages remove the connections to T101
and rewire in accordance with the transformer connections depicted on the schematic
diagram and listed in the following Table 2-1.
TABLE 2-1 POWER TRANSFORMER PRIMARY CONNECTIONS
90-110
104-127
194-237
207-253
A heavy duty 3-wire line cord with molded NEMA style 5-15P plug provides input power.
The power handling ability of the ac lines feeding ac power to the line cord must
be considered, as serious losses in regulation and substantial increases in ripple
can occur as a consequence of insufficient power handling capacity of these lines.
The ac impedance from the breaker box to the power supply input connector should
not exceed 0.75 ohms. 11 ac power line connections must be securely tightened,
and any movable electric contact surface (such as the wiper arm of a variable
transformer) should be kept clear of impedance producing oxide coatings.
2.6 OUTPUT CONNECTION
Output voltage is available at the rear panel terminal barrier strip TB101. The
power supply is shipped from the factory with shorting links connected across the
+V and +S and the -V and -S terminals to allow local sensing and regulation. The
2-2 PQ SERIES-10-79
shorting links may be removed and sense leads connected to the load to allow remote
sensing, noting however, that a voltage drop of 0.5V per power lead must not be
exceeded.
NOTE
If the sense leads are not connected to the load or the
power supply output terminals, rated output can not be
maintained. The power supply must be operated with the
sense leads connected, however, built-in circuitry will
protect the power supply from damage should a sense lead
or shorting link open.
The rear panel barrier strip 18101 is provided with a ground terminal. Either side
of the output (+V or -V) may be grounded, or the output may be used in a floating
condition, providing that the load circuitry is <300V as referenced to earth
ground.
2.7 FRONT PANEL
The controls, indicators, meters and test jacks located on the front panel of the
power supply are described in Table 2-2. Figure 2-1 depicts these locations by
index number.
TABLE 2-2 FRONT PANEL FUNCTIONS
INDEX NAME ` FUNCTION
LOCAL 3-green LED indicators, illuminates when the
VOLTAGE 3-rear panel slot accessible switches are PO,
CURRENT placed in the LOCAL position.
VLIM
ON A rocker switch that allows for the turn-on
and turn-off of the power supply's line power,
illuminates when placed in the ON position.
VOLTS A voltmeter that indicates the output voltage
of the power supply.
AMPERES A ammeter that indicates the current being
supplied to the load by the power supply.
VLIM A red LED indicator that illuminates when the
output of the supply is being limited by the
VLIM function or when the supply is latched in
a OV trip condition.
A recessed screwdriver- adjust potentiometer,
adjust the set point of the V¡¡m from 5%
to 110% of the rated voltage when LOCAL VIIM
is selected.
PQ SERIES-10-79 2-3
TABLE 2-2 FRONT PANEL FUNCTIONS (Cont'd)
CONTROL MODE A green LED indicator, illuminates when the
VOLTAGE power supply is operating in the constant
voltage mode.
CONTROL MODE A amber LED indicator, illuminates when the
CURRENT power supply is operating in the constant
current mode.
VOLTAGE A 10-turn potentiometer, adjusts the
output voltage of the power supply
when local voltage operation is selected.
CURRENT A 10-turn potentiometer, sets the maxi-
mum current supplied to the load when
local current operation is selected.
OUTPUT MONITOR 2-test jacks, allows monitoring the output
5 5 voltage of the power supply.
FIGURE 2-1 FRONT PANEL FUNCTIONS
2-4 PQ SERIES-10-79
2.8 REAR PANEL
The connectors and switches located on, or accessible via the rear panel of the
power supply are described in Table 2-3. Figure 2-2 depicts their location by
index number.
TABLE 2-3 REAR PANEL FUNCTIONS
_ FUNCTION.
A 5-terminal barrier strip, provides output,
sensing and ground connections for the power
supply.
115V 1A (3A) Fuse holder, contains a lÀ or 0.5A (3A or 1.5A)
230 ,,5A (1.5A)| 115 Vac or 230 Vac operation respectively
J2 An access slot to a 20-pin PCB mounted connector
which provides remote programming interface to
the power supply. Refer to Table 2-3 for the
pin designations of this 20-pin programming
connector.
REMOTE 3-access slots to 3 PCB mounted selector switches
V that provides for the independent selection of
I LOCAL control or REMOTE programming of the V,
V I or Viim functions.
LIM
LOCAL
Table 2-4 provides the pin designations for the rear panel accessed 20-pin pro-
gramming connector.
TABLE 2-4 PROGRAMMING CONNECTOR J2
FUNCTION
Interlock (internal interconnection)
Remote O.V. Trip Signal
Ground
+S (All control signals are referenced to +S)
No connection
No connection
PQ SERIES-10-79 2-5
TABLE 2-4 PROGRAMMING CONNECTOR J2 (Cont'd)
PIN
NUMBERS FUNCTION
+V -6.2V
Remote Current Control Input
Remote Vi pm Control Input
Remote Voltage Control Input
FIGURE 2-2 REAR PANEL FUNCTIONS
2-6 PO SERIES-10-79
2.9 OPERATION
The operation of the power supply may be controlled locally or programmed remotely
as to its output voltage, current limiting or VLIM set point. Ascertain which
functions are to be controlled locally or programmed remotely and position the
rear panel accessed V, I and Vm switches to there REMOTE (up) or LOCAL (down)
positions.
CAUTION |
Do Not change the position of the REMOTE-LOCAL
V, I or Vrry Switches when power is applied to
the power supply. Doing so may result in com-
ponent damage, and power supply failure.
Ascertain if local or remote sensing is to be used. If local sensing is to be
used, ensure that the shorting links are installed between the +V and +S and
the -V and -S terminals on the rear panel barrier strip. If remote sensing is
to be used, open the shorting links between the +V and +S and -V and -S terminals.
Connect sense leads between the +S and -S terminals and the load. If long
sensing leads are required they should be a shielded twisted pair, with the
shield grounded at the power supply and the load end left open. Either side of
the output may be grounded or the output may be used in a floating condition.
Ensure that the power leads connecting the +V and -V terminals to the load are
of sufficient gage to carry the maximum current rating of the power supply
(a minimum of 500 circular mils per ampere is recommended).
To determine the proper wire size (AWG) for load leads a monograph (Figure 2-3)
is provided. The wire size is determined by two factors; maximum current carry-
ing capacity recommended for any AWG (500 circular mils per ampere) and the maximum
tolerable voltage drop across the load leads.
To find the maximum current capacity for the standard wire size (AWG), lay a
straight edge from the AWG on scale 2 to point A on scale 3, then read the maximum
011 of Scale E.
To find the voltage drop inmillivolts per foot for a known wire size and operating
current, lay a straight edge from the operating current on scale 1 to the AWG on
scale 2, then read the voltage drop on scale 3.
To find the wire size required for a known operating current and a known maximum
tolerable voltage drop across the supply leads. First, ascertain the maximum
tolerable IR drop in millivolts per foot of lead (sum of positive and negative
leads). Then lay a straight edge from this value on scale 3 to the known op-
erating current on scale 1 and read the wire size in AWG off of scale 2.
PQ SERIES-10-79 2-7
MAXIMUM 3
OPERATING IRDROP IN
CURRENT CONDUCTOR
AMPERES MV/FOOT
100.0 0.5
90.0
80.0
0.6
70.0
60.0 0.7
50.0 08
40.0 0.9
LO
30.0
20.0 2
AMERICAN
15.0 WIRE GAGE =
+
m
o
10.0
15.0
30.0
0.15
40.0
50.0
FIGURE 2-3 LOAD LEAD WIRE SIZE MONOGRAPH
PO SERIES-10-79
2-8
2.9.1 Local Control Operation
Set the rear panel accessed V, I and Vyym Switches to their LOCAL (down) position.
Set the front panel VOLTAGE and CURRENT controls full CCW. Rotate the V¡ ¡yq SET
screwdriver adjustment potentiometer full CW. Set the power switch to its ON
position and verify that the power switch indicator lights and the LOCAL, VOLTAGE,
CURRENT and V LED lights. As soon as the power switch is set ON, the power
supply is ready" for use. However, a 30 minute warmup ponies is recommended for
the supply to reach its rated stability.
To set up the power supply for Constant Voltage Operation With Current Limiting
perform the following steps:
1. Monitor the front panel VOLTS meter, or connect a DVM to the OUTPUT MONITOR
jacks, and adjust the VOLTAGE control for the required output voltage. If the
power supply is equipped with option 09 control locks, lock the VOLTAGE control.
2. Place a short across the +V and -V terminals on the rear panel barrier
Strip.
3. Monitor the front panel AMPERES meter and adjust the CURRENT control for
the required maximum current output (current limit level). If the power supply
is equipped with control locks, lock the CURRENT control.
4. Remove the short from the +V and =V terminals.
To set the Vi im level perform the following steps:
1. Monitor the front panel VOLTS meter, or connect a DVM to the OUTPUT
MONITOR jacks.
2. Adjust the VOLTAGE control to the required V¡ ¡qm point, as indicated on the
VOLTS meter or DVM.
3. Rotate the V¡¡m SET screwdriver adjustment CCW until the Vy LED in-
dicator just illuminates.
4. With the VOLTAGE control reduce the output voltage and verify that the
VLm LED extinguishes. Then slowly increase the output voltage and verify that
the Vitry LED lights at the required VIM set point.
5. Reset the VOLTAGE control to the required output voltage and lock the
control.
The power supply will provide constant current operation automatically, when the
load demand exceeds the current level set by the CURRENT control. When the
supply switches into its constant current control mode the CONTROL MODE CURRENT
LED illuminates and the CONTROL MODE VOLTAGE LED extinguishes. The point at
which the constant voltage/constant current mode change takes place is a func-
tion of variations in load conditions and will occur at a critical value of load
resistance Rc = Es/Ig, where E¿ is the front panel VOLTAGE control setting and
Ig is the front panel CURRENT control setting.
PQ SERIES-10-79 2-9
2.9.2 Remote Programming Operation
Set the rear panel accessed V, I and VLIM switches to their REMOTE (up). position.
Do Not change the position of the REMOTE - LOCAL
V, I or Vpry Switches when power is applied to
the power supply. Doing so may result in com-
ponent damage and power supply failure.
Set the power switch to its ON position and verify that the power switch indicator
illuminates. Verify that the LOCAL - VOLTAGE, CURRENT and im LED indicators
are extinguished, thus indicating that local front panel control of the functions
are disabled and the supply may be controlled by a remote programming source.
Connect the programming device via cable and connector to the rear panel accessed
J2 connector. Table 2-5 provides the remote programming format for the P-Series
power supplies.
TABLE 2-5 P-SERIES PROGRAMMING FORMAT
PROGRAM 0
FUNCTION CONNECTIONS PROGRAM OPERATION
Voltage Output (V) 10 and L 00.0 to+10.0V provides 00% to 100% of
the rated output voltage.
Current Limit (1) 8 and J O to-1mA provides 00% to 100% of the
rated current limit level.
Voltage Limiting (Vi 1m)J 9 and K 00.0 to+10.9V provides 00% to 109%
of the rated output voltage as the
VLIM set point.
Note: All program inputs are referenced to the + Sense (+S) J2 pins 4 and D.
NOTE
If for amy reason the output voltage of the supply
should momentarily exceed the Vrry set point by
1% of the full output voltage rating, the 0.V. eir-
cuit will trip crowbaring the output of the supply.
The 0.V. trip condition is indicated by the illu-
mination of the red Vrry LED and a zero indication
on the panel voltmeter. Remotely it is signalled
by an 0.V. flag as a voltage level between pins
2, Band 7, H of
If no failure has occurred the 0.V. trip can be
cleared and operation restored by cycling the power
ON switch to off and then back ON.
2-10 PQ SERIES-10-79
CHAPTER 3
PRINCIPLES OF OPERATION
3.1 P-SERIES FUNCTIONAL DESCRIPTION
The following functional description is referenced to Figure 3-1 P-Series Function-
al Schematic Diagram, which depicts the power supply in a simplified form. The
schematic diagram located at the end of Chapter 5 of this manual (Model PQ Sche-
matic 7D065367) further supports the circuit analysis of the P-Series power
supplies. Reference designators assigned to the electronic components are divided
into two numerical series; 1 through 99 PCB assembly mounted components and 101
through 199 chassis, heatsink, front and rear panel mounted components.
The overall function of the power supply is to transform and rectify the ac input
line voltage into a well regulated, stable, and adjustable dc output. In perform-
ing these functions the circuitry can be divided into the following subfunctions.
1 Main Rectifier and Filter
2 Auxiliary Rectifier and Filter
3 Auxiliary Regulator
4 Series Pass Regulator
S. Voltage Error Amplifier
6 Current Control Amplifier
7. Over Voltage '"Crowbar'" Comparator and Voltage Limiter 00 Comparator
8 Current Sink Circuit
3.2 CIRCUIT ANALYSIS
The following circuit analysis is referenced to Figure 3-1 and the schematic
diagram located at the end of Chapter 5 of this manual.
3.2.1 Primary Input, Rectifiers and Filter Circuits
The input power is obtained through power transformer 1101. Bridge rectifier
U101 in model PH or diodes CR109 through CR112 in model PQ provides the raw
voltages which are applied to the series pass regulators. Capacitors C101 and
C102 constitute the filter. Full wave rectifier CRl and CR2 provides for the
auxiliary regulator +15 volt rectification and capacitor C3 provides its filtering
function. Full wave rectifier CR5 and CR6 provides +8V on top of +V for the
drivers and capacitor C6 provides its filtering function. Full wave rectifier 7
and CR8 provides the rectification for the three LOCAL MODE LED's CR103, CR104
and CR105.
When the front panel ac power switch 5101 is placed into its ON position its
internal neon lamp will light and ac power is applied to the primary of trans-
former 1101 and regulated dc output power is immediately made available at the
rear panel barrier strip 18101 +V and -V terminals. Overload protection is
provided by an input line fuse F101.
PQ SERIES-1-80 Co1
3.2.2 Series Pass Regulator Circuit
The dc voltage from the load rectifier is directed through the series pass transis-
tors:
The PQ supplies utilize two series pass transistors connected in series (0101 and
Q102). Transistor Q101 conduction is controlled by the source regulator Q9 and
transistor Q102 conduction is controlled by the voltage amplifier output at U2
pin 6 via transistor Q4.
The PH supplies utilize four series pass transistors in a series-parallel con-
figuration to provide the greater power ratings of the half rack modules. Tran-
sistors Q101 and Q102 connected in parallel are controlled by the source regulator
Q12 and transistors Q103 and Q104 also connected in parallel are controlled by
the voltage amplifier output U2 pin 6 via transistor 04.
3.2.3 Auxiliary Regulator Circuit
The rectified and filtered voltages from rectifiers CRl and CR2 and capacitor C3
are applied to the auxiliary series pass transistor Q2 and the constant current
source FET Ql. The conduction of Q2 is controlled by IC differential amplifier
Ul. The auxiliary regulator circuit supplies highly stable reference voltages
that are referenced to the +S and +V lines. These reference voltages are listed
as follows with their associated zener reference diode.
1. +S +9V CR4
2. +5 +15 CR3
3. + -6.2V 5
3.2.4 Voltage Error Amplifier Circuit
The voltage error amplification is accomplished by IC differential amplifier U2.
The +S signal is applied to the inverting input of U2 at pin 2. A voltage level
that relates to the desired output power supply voltage is applied to the non-
inverting input of U2 at pin 3. This value is set by the front panel VOLTAGE
control potentiometer R112 when local operation is selected via switch Sl. When
remote voltage control is selected the set point value is obtained from the rear
panel programming connector J2 pins 10 and L via switch Sl.
If the output voltage of the power supply changes due to loading effect, the
error (difference between the +S and voltage levels) appears as a voltage change
at U2 pin 6. This error voltage is then applied to the series pass transistor
circuit via emitter follower Q4 as base bias.
3.2.5. Current Control Circuit
The current control circuit provides constant current control when in the current
mode or current limiting when the supply is being used in the voltage mode.
The crossover between constant voltage to constant current mode is automatic. The
point at which the operating mode automatically changes is a function of the
external load and occurs at a critical value of the load resistance R = 5/1
where Es is the voltage control setting and Is is the current control setting.
3-2 PQ SERIES-1-80
Iii -
caeral
1
! "EXP @
PQ
SERIES-1-81
The current control is accomplished by IC differential amplifier U3. The power
supply's output current is monitored by the voltage drop across the current sensing
resistor R70. The tap at the +V end of resistor R70 is applied to U3 pin 3 as the
reference level. The other tap provides a positive current feedback of up to 1 mA
to the summing junction (pin 2) of U3.
In the local control of current, the feedback current flows through the 100 ohm
front panel CURRENT CONTROL potentiometer R110 to the summing junction, while a fixed
-1 mA flows from the -6.2 volts rail through R60 and Local I Cal potentiometer R61.
If the feedback current is less than +1 mA, the net current to pin 2 of U3 is negative,
so that its output will be at a high positive level determined by clamp diode
CR33. In this condition, the current amplifier is disconnected from the drive
circuitry by diode 0815 and has no effect on either the output voltage or current.
The output voltage is determined by the voltage error amplifier U2.
As the load resistance is decreased and the current increases, a point will be
reached where the voltage developed across R70 divided by the resistance of the
current control R110 will equal 1 mA. The currents to the summing junction, U3
pin 2, will then be equal and opposite, and the potential at that point will be
the same as pin 3. Because pin 2 is the inverting input, as its potential rises,
the output of U3 will drop from its clamp level to a point where CR15 begins to
conduct. This then takes over control of U2. Any further decrease in the load
resistance will cause the feedback current to pin 2 to increase slightly, thus also
increasing the voltage. The output of U3 will then