Agilent Technologies HP8648A Service manual

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·· )/ ·· Ag 1ilent: Technoli0g1 : es
6516A DC Power Supply Operating and Service Manual
October 1967
06516-90001

DC POWER SUPPLY
HVB SERIES, MODEL 6516A
SERIAL NUMBER PREFIX 70
Printed: October, 1967
dij; Stock Number: 06516-90001

TABLE OF CONTENTS
Section
Page No. Section
Page No.
I GENERAL INFORMATION
.............. 1-1 IV PRINCIPLES OF OPERATION (Continued)
1-1
Description 1-1
4-24
High Voltage Control and
1-4
Overload Protection
1-1
Doubler Circuits
4-4
1-7
Cooling 1-1
4-28 Protection Circuit
4-5
1-9
Output Terminals 1-1
4-30
Reference Regulator
4-5
1-11
Specifications 1-1
1-13
Options 1-1
V MAINTENANCE.
..................... 5-1
1-15
Accessories 1-1 5-1
Introduction
5-1
1-17
Instrument Identification
1-2 5-3 High Voltage Precautions
5-1
1-20
Ordering Additional Manuals
1-2
5-6
Measurement Techniques
5-1
5-9
Test Equipment Required
5-1
I I INSTALLATION
...................... 2-1 5-11
Performance Test
5-4
2-1
Initial Inspection 2-1
5-14 Rated Output, Meter, and Output
2-3 Mechanical Check 2-1
Controls Accuracy
5-4
2-5
Electrical Check 2-1 5-17
Load Regulation
5-4
2-7 Installation Data
2-1 5-19 Line Regulation
5-5
2-9 Location
2-1 5-21
Ripple and Noise
5-5
2-11
Rack Mounting 2-1
5-35 Transient Recovery Time
5-7
2-15
Input Power Requirements 2-2 5-39
Output Impedance
5-8
2-17
Power Cable
2-2
5-42
Temperature Coefficient
5-9
2-20
Repackaging for Shipment 2-2 5-46
Output Stability
5-9
5-49
Current Limit
5-10
III OPERATING INSTRUCTIONS ........... 3-1 5-51
Troubleshooting
5-10
3-1
Turn-on Check Out Procedure 3-1
5-55
Overall Troubleshooting
3-3 Operation 3-1
Procedure
5-10
3-5
Current Limit Provisions 3-1 5-59
Repair and Replacement
5-15
3-7
Operation of Supply Beyond
5-61
Adjustment and Calibration
5-17
Rated Output 3-1 5-62
Meter Zero
5-17
3-9 Load Connection
3-i
5-64
Meter Accuracy Adjustment
5-17
3-13
Output Capacitance 3-2
5-66
Output Voltage (Programming
3-15
Reverse Current Loading 3-2 Current) Adjustment
5-17
3-17 Reverse Voltage Loading 3-2 5-68
Output Current Limit Adjustment
5-17
5-70 Overvoltage Protection
5-17
IV
PRINCIPLES OF OPERATION ........... 4-1
4-1 Overall Block Diagram VI
REPLACEABLE PARTS ................. 6-1
Discussion 4-2 6-1
Introduction
6-1
4-8
Simplified Schematic Discussion 4-3 6-4 Ordering Information
6-1
4-12 Detailed Circuit Analysis 4-4
Reference Designators
4-13 :;ieries Regulator 4-4 Abbreviations
4-15 Constant Voltage Input Circuit 4-4 Manufacturers
4-20 Driver Amplifier 4-4
6-8
Code List of Manufacturers
6-2
4-22 Current Limit Circuit 4-4 Parts List Table
6-5
ii

Figure
Table
1-1
5-1
5-2
5-3
5-4
1-1 DC Power Supply
TABLE OF CONTENTS (CONTINUED)
LIST OF TABLES
Pege No.
Specifications. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 ~3
Test Equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-3
Bias, Reference, and Rectifier Voltages ....... 5-10
Low Output Voltage Troubleshooting .......... 5-12
High Output Voltage Troubleshooting ......... 5-14
LIST OF ILLUSTRATIONS
Page No. Figure
iv
5-3 Line and Load Regulation,
2-1 Rack Mounting, Two Units
2-2 Rack Mounting, One Unit
2-1
2-2
5-4
Test Setup
Ripple and Noise, Test Setup
3-1 Front Panel Controls and Indicators
4-1 Overall Block Diagram
3-1
4-1
5-5
5-6
High Voltage Protection Network
Noise Spikes,
Test Setup
Page No.
5-4
5-5
5-6
5-7
4-2 Simplified Schematic Diagram 4-3 5-7 Transient Recovery Time,
Test Setup 5-8
5-1 High Voltage and Troubleshooting
Location Diagram
5-2 Differential Voltmeter Substitute,
Test Setup
5-2
5-4
5-8
5-9
5-10
i i i
Transient Recovery Time Waveforms
5-8
Output Impedance, Test Setup
5-8
Servicing Printed Wiring Boards
5-16

LINE
,,,:~t1 0•1/0.:r
+
VOLTAGE
Figure 1-1. DC Power Supply, Model 6516A
i V

SECTION I
GENERAL INFORMATION
1-1 DESCRIPTION
1-2 This instrument (Figure 1-1) is an all semi-
conductor high voltage supply suitable for either
bench or relay rack operation. It is a compact,
well-regulated, Constant Voltage/Current Limited
supply that will furnish 3,000 volts at 6 milliamps
or can be adjusted throughout the output voltage
range. It is designed for applications requiring
extreme stability, regulation, and insensitivity to
ambient temperature variations.
1-3 This supply utilizes a series regulated
"piggy-back" circuit technique that consists of
placing a well-regulated low voltage power supply
in series with a less well-regulated supply having
a greater voltage capability. The well-regulated
"piggy-back" supply continuously compensates for
any ripple, load regulation, or line regulation de-
ficiencies of the main power source and adjusts
the voltage across its series regulator so that the
total output voltage remains constant despite dis-
turbances in the main voltage source.
1-4 OVERLOAD PROTECTION
1-5 The voltage thumbwheel switches select the
constant voltage level; an internal potentiometer
selects the current limit level. The supply will
automatically crossover from constant voltage to
current limit operation and vice versa if the output
current or voltage exceeds these preset levels.
Detailed characteristics of the output current lim-
iting are given in Paragraph 3-5.
1-6 The power supply is protected from reverse
voltage (positive voltage applied to negative ter-
minal) by an internal protection diode that shunts
current across the output terminals when this con-
dition exists, clamping the reverse voltage. Pro-
tection from reverse current (current forced into
the power supply in the direction opposite to the
output current) must be provided by preloading the
power supply (Paragraph 3-15). The power supply
cannot accept reverse current without damage.
1-7 COOLING
1-8 Convection cooling is used; no fan is re-
quired. The power supply has no moving parts
except for the meter movement.
1-1
1-9 OUTPUT TERMINALS
1-10 Output power is ava~lable via two UG-931/U
connectors mounted on the front panel of the sup-
ply. Mating connectors (UG-932/U) are supplied
with the unit. The output terminals are isolated
from the chassis and either the positive or the neg-
ative terminal may be connected to the chassis by
shorting the center pin to the case of the applica-
ble UG-931/U connector, or by grounding a wire
from the connector to the chassis. The power sup-
ply is insulated to permit operation up to 1, 000
volts de off ground, i.e. the maximum potential
between either output terminal and ground shall not
exceed 4KVdc.
1-11 SPECIFICATIONS
1-12 Detailed specifications for the power supply
are given in Table 1-1.
1-13 OPTIONS
1-14 Options are factory modifications of a stand-
ard instrument that are requested by the customer.
The following options are available for the instru-
ment covered by this manual. Where necessary,
detailed option information (operation, alignment,
etc.) is included throughout the manual.
Option No. Description
OS S0Hz Input Modification. Factory
18
modification includes the substitution
of 6 0Hz with S 0Hz magnetic compo-
nent as indicated at the end of the
parts list in Section VI. In addition,
the overvoltage protection adjustment
is rechecked, refer to Section V.
230Vac ±10%, Single-Phase Input.
Factory modification includes the in-
stallation of a 230 volt input trans-
former to replace the standard 115 volt
transformers as in die a ted at the rear
of the parts list in Section VI.
1-15 ACCESSORIES
1-16 The accessories listed in the following chart
may be ordered with the power supply or separately

from your local 0j,, sales office. (Refer to list at
rear of manual for addresses.) Additional informa-
tion on accessories is given in Section II.
rffe, Part No,
145 lSA
14525A
Description
Raek Kit for Mounting one 5¼" H
supply in a standard 19" EIA rack.
(Refer to Section II for details.)
Rack Kit for mounting two S¼" H
supplies in a standard 19" EIA rack.
(Refer to Section II for details.)
1-17 INSTRUMENT IDENTIFICATION
1-18 Hewlett-Packard power supplies are identi-
fied by a three-part serial number tag. The first
part is the power supply model number. The sec-
ond part is the serial number prefix, which consists
of a number-letter combination that denotes the
date of a significant design change. The number
1-2
designates the year, and the letter A through L
designates the month, January through December,
respectively. The third part is the power supply
serial number; a different sequential number is as-
signed to each power supply,
1-19 If the serial number prefix on your power
supply does not agree with the prefix on the title
page of this manual, use the change page that is
included to update the manual to the proper serial
number. Where applicable, backdating information
is given in an appendix at the rear of the manua·l.
1-20 ORDERING ADDITIONAL MANUALS
1-21 One manual is shipped with each power sup-
ply. Additional manuals may be purchased from
your local<&, sales office (see list at rear of this
manual for addresses). Specify the model number,
serial number prefix, and 0j,, stock number provided
on the title page.

Table 1-1.
OUTPUT:
0-3000Vdc, 0-6 milliamperes.
INPUT:
llSVac ±10%, single phase, 57-63Hz, lA, 40W.
LOAD REGULATION:
Less than 0.01% or 16mV (whichever is greater)
output voltage change for a full load to no load
change in output current.
LINE REGULATION:
Less than 0.01% or 16mV (whichever is greater)
output voltage change for a 10% change in the
nominal line voltage.
RIPPLE AND NOISE:
Less than 2mVrms, SmV p-p.
TEMPERATURE RANGES:
Operating: 0 to ss
0c.
Storage: -20 to +ss
0c.
TEMPERATURE COEFFICIENT:
Less than 0. 02% +2mV output voltage change
per
0c
after 30 minute warm-up.
STABILITY:
Less than 0. 05% +SmV total drift for 8 hours
after 30 minute warm·-up and with 30c ambient
variation.
OUTPUT IMPEDANCE:
Less than 32 ohms from de to 30Hz.
Less than 8 ohms from 30Hz to l0OkHz.
Less than 2 ohms from lO0kHz to 1MHz.
TRANSIENT RECOVERY TIME:
Less than 100µ seconds is required for output
voltage to recover to within 0.01% or 16mV of the
nominal output voltage following a full load
change in output current. The nominal output
Specifications
1-3
voltage is defined as the mean between the no
load and full load voltage.
OVERLOAD PROTECTION:
An all electronic, continuously acting current
limit protects the power supply for all overloads
regardless of how long imposed, including a di-
rect short circuit across the output terminals.
CONTROLS:
An in-line 4-digit (thumbwheel) voltage program-
mer permits control of the output voltage; resolu-
tion is lV.
METER:
The front panel meter is a 0-35 00V voltmeter.
OUTPUT TERMINALS:
The de output of the supply is floating; thus,
the supply can be used as either a positive or
negative source. Terminals for +OUT, -OUT,
and GND are provided on the front of the supply.
COOLING:
Convection cooling is employed. The supply
has no moving parts.
SIZE:
B½" W x 5¾" H x 16" D. Two of the units can be
mounted side by side in a standard 19" relay rack.
WEIGHT:
17 lbs. net, 20 lbs. shipping.
FINISH:
Light gray front panel with dark gray case.
POWER CORD:
A 3-wire 5-foot power cord is provided with each
unit.

SECTION II
INSTALLATION
2-1 INITIAL INSPECTION
2-2 Before shipment, this instrument was in-
spected and found to be free of mechanical and
electrical defects. As soon as the instrument is
unpacked, inspect for any damage that may have
occurred in transit, Save all packing materials
until the inspection is completed. If damage is
found, proceed as described in the Claim for
Damage in Shipment section of the warranty page
at the rear of this manual.
2-3 MECHANICAL CHECK
2-4 This check should confirm that there are no
broken knobs or connectors, that the cabinet and
panel surfaces are free of dents and scratches,
and that the meter is not scratched or cracked.
2-5 ELECTRICAL CHECK
2-6 The instrument should be checked against
its electrical specifications. Section V includes
an "in-cabinet" performance check to verify proper
instrument operation.
2-7 INSTALLATION DATA
2-8 The instrument is shipped ready for bench
operation. It is necessary only to connect the in-
strument to a source of power and it is ready for
operation.
2-9 LOCATION
2-10 This instrument is air cooled. Sufficient
space should be allotted so that a free flow of
cooling air can reach the sides and rear of the in-
strument when it is in operation. It should be used
in an area where the ambient temperature does not
exceed ssoc.
2-11 RACK MOUNTING
2-12 This instrument may be rack mounted in a
standard 19 inch rack panel either alongside a
similar unit or by itself. Figures 2-1 and 2-2
show how both types of installations are accom-
plished.
- 0
__ ,o
Figure 2-1. Rack Mounting, Two Units
2-1

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Q Q
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Q G g e
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-
Figure 2-2. Rack Mounting, One Unit
2-13 To mount two units side-by-side, proceed
as follows:
a. Remove the four screws from the front
panels of both units.
b. Slide rack mounting ears between the
front panel and case of each unit.
c. Slide combining strip between the front
panels and cases of the two units.
d. After fastening rear portions of units to-
gether using the bolt, nut, and spacer, replace
panel screws.
2-14 To mount a single unit in the rack panel,
proceed as follows:
a. Bolt rack mounting ears, combining
strips, and angle brackets to each side of center
spacing panels. Angle brackets are placed be-
hind combining strips as shown in Figure 2-2.
b. Remove four screws from front panel of
unit.
c. Slide combining strips between front
panel and case of unit.
d. Bolt angle brackets to front sides of case
and replace front panel screws.
2-15 INPUT POWER REQUIREMENTS
2-16 This power supply is operated from a nominal
115 volt 60 Hz power source. The input power re-
quired when operated from a 115 volt 60 Hz power
source at full load is:
Model 6110A 60 Watts
Model 6516A 40 Watts
2-2
2-17 POWER CABLE
2-18 To protect operating personnel, the National
Electrical Manufacturers Association (NEMA) rec-
ommends that the instrument panel and cabinet be
grounded. This instrument is equipped with a
three conductor power cable. The third conductor
is the ground conductor and when the cable is
plugged into an appropriate receptacle, the instru-
ment is grounded. The offset pin on the power
cable three-prong connector is the ground connec-
tion.
2-19 To preserve the protection feature when op-
erating the instrument from a two-contact outlet,
use a three-prong to two-prong adapter and con-
nect the green lead on the adapter to ground.
2-20 REPACKAGING FOR SHIPMENT
2-21 To insure safe shipment of the instrument, it
is recommended that the package designed for the
instrument be used. The original packaging mate-
rial is reusable. If it is not available, contact
your local Hewlett-Packard field office to obtain
the materials. This office will also furnish the
address of the nearest service office to which the
instrument can be shipped. Be sure to attach a
tag to the instrument which specifies the owner,
model number, full serial number, and service re-
quired, or a brief description of the trouble.