Agilent E3620A Service Manual

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DUAL OUTPUT POWER SUPPLY

Agilent MODEL E3620A

OPERATING AND SERVICE MANUAL

FOR INSTRUMENTS WITH SERIAL NUMBERS

KR71804262 AND ABOVE

For instruments with Serial Numbers above

KR71804262, a change page may be included.

Manual Part No. E3620-90001

April 2000

Edition 6

SAFETY SUMMARY

The following general safety precautions must be observed during all phases of operation, service, and repair of this instrument.
Failure to comply with these precautions or with specific warnings elsewhere in this manual violates safety standards of design,
manufacture, and intended use of the instrument. Agilent Technologies assumes no liability for the customer's failure to comply
with these requirements.

BEFORE APPLYING POWER.

Verify that the product is set to match the available line volt­age and that the correct fuse is installed.

GROUND THE INSTRUMENT.

This product is a Safety Class I instrument (provided with a
protective earth terminal). To minimize shock hazard, the
instrument chassis and cabinet must be connected to an
electrical ground. The instrument must be connected to the
ac power supply mains through a three-conductor power
cable, with the third wire firmly connected to an electrical
ground(safety ground) at the power outlet. Any interruption of
the protective(grounding) conductor or disconnection of the
protective earth terminal will cause a potential shock hazard
that could result in personal injury. If the instrument is to be
energized via an external autotransformer for voltage reduc­tion, be certain that the autotransformer common terminal is
connected to the neutral(earthed pole) of the ac power lines
(supply mains).

DO NOT OPERATE IN AN EXPLOSIVE ATMOSPHERE.

Do not operate the instrument in the presence of flammable
gases or fumes.

KEEP AWAY FROM LIVE CIRCUITS.

Operating personnel must not remove instrument covers.
Component replacement and internal adjustments must be
made by qualified service personnel. Do not replace compo­nents with power cable connected. Under certain conditions,
dangerous voltages may exist even with the power cable
removed. To avoid injuries, always disconnect power, dis­charge circuits and remove external voltage sources before
touching components.

SAFETY SYMBOLS

!

or

WARNING

CAUTION

NOTE

Instruction manual symbol; the product
will be marked with this symbol when it is
necessary for the user to refer to the
instruction manual.

Indicate earth(ground) terminal.

The WARNING sign denotes a hazard. It
calls attention to a procedure, practice,
or the like, which, if not correctly per­formed or adhered to, could result inper­sonal injury. Do not proceed beyond a
WARNING sign until the indicated con­ditions are fully understood and met.

The CAUTION sign denotes a hazard. It
calls attention to an operating procedure,
or the like, which, if not correctly per­formed or adhered to, could result in
damage to or destruction of part or all of
the product. Do not proceed beyond
CAUTION sign until the indicated condi­tions are fully understood and met.

The NOTE sign denotes important infor­mation. It calls attention to a procedure,
practice, condition or the like, which is
essential to highlight.

DO NOT SERVICE OR ADJUST ALONE.

Do not attempt internal service or adjustment unless another
person, capable of rendering first aid and resuscitation, is
present.

Instruments that appear damaged or defective should be made inoperative and secured against unintended
operation until they can be repaired by qualified service personnel.

DO NOT SUBSTITUTE PARTS OR MODIFY INSTRUMENT.

Because of the danger of introducing additional hazards, do
not install substitute parts or perform any unauthorized modi­fication to the instrument. Return the instrument to a Agilent
Technologies Sales and Service Office for service and repair
to ensure that safety features are maintained.

1-2

Table of Contents

SAFETY SUMMARY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2

GENERAL INFORMATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-4

DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-4

SAFETY CONSIDERATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-4

SAFETY AND EMC REQUIREMENTS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-4

INSTRUMENT AND MANUAL IDENTIFICATION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-4

OPTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-4

ACCESSORY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-4

ORDERING ADDITIONAL MANUALS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-4

SPECIFICATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-4

LINE FUSE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-5

INSTALLATION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-5

INITIAL INSPECTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-5

Mechanical Check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-5

Electrical Check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-5

INSTALLATION DATA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-5

Location and Cooling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-5

Outline Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-6

Rack Mounting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-6

INPUT POWER REQUIREMENTS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-6

Power Cable. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-6

OPERATING INSTRUCTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-6

INTRODUCTION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-6

CONTROLS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-6

Line Switch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-6

Voltage and Current Metering . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-6

Voltage Controls. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-6

TURN-ON CHECKOUT PROCEDURE. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-7

OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-7

Overload Protection Circuits. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-7

Operation Beyond Rated Output . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-7

Connecting Load . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-7

Series Operation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-7

Parallel Operation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-7

LOAD CONSIDERATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-7

PULSE LOADING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-7

REVERSE CURRENT LOADING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-8

OUTPUT CAPACITANCE. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-8

REVERSE VOLTAGE PROTECTION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-8

1-3

GENERAL INFORMATION

DESCRIPTION

The Model E3620A Dual Output Power Supply is a compact,
constant voltage/current limiting supply that delivers two iso­lated 0 to 25 V outputs rated at 1 A. It is an ideal power supply
for design and breadboard work where single or dual voltages
are required. Each output voltage is continuously variable
throughout its range and separate current limit circuits protect
each output against overload or short circuit damage.

Connections to the outputs are made to binding post type ter­minals on the front panel. The outputs can be used individu­ally or in combination to satisfy any number of output
demands. The positive or negative terminal of each output
can be grounded or each output can be left floating. A chassis
ground terminal is located on the front panel of the supply.

The front panel also contains a line switch, output voltage
controls, an autoranging digital voltmeter and a single-range
digital ammeter, and two meter select pushbutton switches.
The meter pushbuttons select both voltage and current
monitoring for the output V1 and V2. The supply is furnished
with a detachable, 3-wire grounding type line cord. The ac
line fuse is an extractor type fuseholder on the rear heat sink.

SAFETY CONSIDERATIONS

This product is a Safety Class I instrument, which means that
it is provided with a protective earth ground terminal. This ter­minal must be connected to an ac source that has a 3-wire
ground receptacle. Review the instrument rear panel and this
manual for safety markings and instructions before operating
the instrument. Refer to the Safety Summary page at the
beginning of this manual for a summary of general safety
information. Specific safety information is located at the
appropriate places in this manual.

SAFETY AND EMC REQUIREMENTS

This power supply is designed to comply with the following
safety and EMC(Electromagnetic Compatibility) require­ments:

n IEC 1010-1(1990)/EN 61010 (1993): Safety Require-

ments for Electrical Equipment for Measurement, Control,
and Laboratory Use

n CSA C22.2 No.231: Safety Requirements for Electrical

and Electronic Measuring and Test Equipment

n UL 1244: Electrical and Electronic Measuring and Testing

Equipment

n EMC Directive 89/336/EEC: Council Directive entitled

Approximation of the Laws of the Member States relating
to Electromagnetic Compatibility

n EN 55011(1991) Group 1, Class B/CISPR 11 (1990):

Limits and Methods of Radio Interference Characteristics
of Industrial, Scientific, and Medical(ISM) Radio­Frequency Equipment

n EN 50082-1(1992) /

IEC 801-2(1991): Electrostatic Discharge Requirements
IEC 801-3(1984): Radiated Electromagnetic Field

Requirements

IEC 801-4(1988): Electrical Fast Transient/Burst

Requirements

INSTRUMENT AND MANUAL IDENTIFICATION

A serial number identifies your power supply. The serial num­ber encodes the country of manufacture, the week of the lat­est significant design change, and a unique sequential
number. The letter "KR" designates Korea as the country of
manufacture, the first one digit indicates the year (4=1994,
5=1995, and so forth), and the second two digits indicate the
week. The remaining digits of the serial number are a unique,
five-digit number assigned sequentially.

If the serial number on your supply does not agree with those
on the title page of the manual, a yellow Change Sheet is
supplied with the manual to explain the difference between
your instrument and the instrument described by this manual.
The Change Sheet may also contain information for correct­ing errors in the manual.

OPTIONS

Options 0E3 and 0E9 determine which line voltage is
selected at the factory. The standard unit is configured for 115
Vac ± 10%, 47-63 Hz input.

Option No. Description

0E3: 230 Vac ± 10%, 47-63 Hz Input
0E9: 100 Vac ± 10%, 47-63 Hz Input

ACCESSORY

The accessory listed below may be ordered from your local
Agilent Technologies Sales Office either with the power sup­ply or separately. (Refer to the list at the rear of the manual for
address.)

Agilent Part No. Description

5063-9240 Rack Kit for mounting one or two 3 1/2" high

supplies in a standard 19" rack

The rack mount kit is needed for rack mounting of the
E3620A power supply.

ORDERING ADDITIONAL MANUALS

One manual is shipped with each power supply. (Option 910
is ordered for each extra manual.) Additional manuals may
also be purchased separately for your local Agilent Technolo­gies sales office (see the list at the rear of this manual for
addresses). Specify the model number, serial prefix, and the
Agilent Part Number provided on the title page.

SPECIFICATIONS

Instrument specifications are listed in Table 1. These specifi­cations are performance standards or limits against which the
instrument is tested.

1-4

LINE FUSE

The line fuse is located by the ac line receptacle. Check the
rating of the line fuse and replace it with the correct fuse if
necessary as indicated below. These are slow-blow fuses.

Table 1. Specifications

Line Voltage Fuse Agilent Part No.

100/115 Vac 2 A 2110-0702
230 Vac 1 A 2110-0457

AC INPUT

Standard:
0E9:
0E3:

DC OUTPUT

Voltage span over which output may be varied using front
panel controls.

Output V1:
Output V2:

LOAD REGULATION

Less than 0.01% plus 2 mV for a full load to no load change in
output current.

LINE REGULATION

Less than 0.01% plus 2 mV for any line voltage change within
rating.

RIPPLE AND NOISE

Normal Mode Voltage:
(20 Hz-20 MHz).
Common Mode Current (CMI):
outputs (20 Hz-20 kHz).

OPERATING TEMPERATURE RANGE

0 to 40

output current is derated linearly to 50% at 55
temperature.

TEMPERATURE COEFFICIENT

Less than 0.02% plus 1 mV voltage change per

operating range from 0 to 40

115 Vac ± 10%, 47-63 Hz, 200 VA, 130 W
100 Vac ± 10%, 47-63 Hz, 200 VA, 130 W
230 Vac ± 10%, 47-63 Hz, 200 VA, 130 W

0 to 25 V at 1 A
0 to 25 V at 1 A

Less than 0.35 mV rms/1.5 mV p-p

Less than 1 mA rms for all

o

C for full rated output. At higher temperatures,

o

C after 30 minutes warm-up.

o

C maximum

o

C over the

STABILITY (OUTPUT DRIFT)

Less than 0.1% plus 5 mV (dc to 20 Hz) during 8 hours at
constant line, load and ambient after an initial warm-up time
of 30 minutes.

LOAD TRA NSIENT RESPONSE TIME

Less than 50 msec for output recovery to within 15 mV of
nominal output voltage following a load change from full
load to half load, or vice versa.

OUTPUT VOLTAGE OVERSHOOT

During turn-on or turn-off of ac power, output plus overshoot
will not exceed 1 V if the output control is set for less than 1 V.
If the control is set for 1 V or higher, there is no overshoot.

METER ACCURA CY: ±(0.5% of output + 2 counts)

o

C±5oC

at 25

METER RESOLUTION

Voltage:
Current:

DIMENSIONS

212.3 mmW x 88.1 mmH x 345.4 mmD
(8.4 inW x 3.5 inH x 13.6 inD)

WEIGHT

5.0 kg(11.0 lbs) net, 6.25 kg(13.8 lbs) shipping

10 mV (0 to 20 V),100 mV (above 20 V)
1 mA

INSTALLATION

INITIAL INSPECTION

Before shipment, this instrument was inspected 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, a claim should
be filed with the carrier. The Agilent Technologies Sales and
Service office should be notified as soon as possible.

Mechanical Check

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.

Electrical Check

This instrument should be checked against electrical specifi­cations. Perform the TURN-ON CHECKOUT PROCEDURE
in the following paragraph to confirm that the supply is
operational. Alternately, check the supply more fully using the
PERFORMANCE TEST in the service information section.

INSTALLATION DATA

The instrument is shipped ready for bench operation. Before
applying power to the supply, please read the INPUT
POWER REQUIREMENTS paragraph.

Location and Cooling

This instrument is air cooled. Sufficient space should be allowed
so that a free flow of cooling air can reach the sides and rear of
the instrument when it is in operation. It should be used in an
area where the ambient temperature does not exceed 40

1-5

o

C.

Outline Diagram

Figure 1 illustrates the outline shape and dimensions of the
supply.

Rack Mounting

This supply may be rack mounted in a standard 19-inch rack
panel either by itself or alongside a similar unit. Please see
the ACCESSORY, page 1-4, for available rack mounting
accessory. The rack-mounting kit includes complete installa­tion instructions.

INPUT POWER REQUIREMENTS

Depending on the line voltage option ordered, the supply is
ready to be operated from one of the power sources listed in
Table 1. A label on the rear heat sink shows the nominal input
voltage set for the supply at the factory.

Power Cable

To protect operating personnel, the supply should be
grounded. This supply 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
supply is grounded. The power supply is equipped at the fac­tory with a power cord plug appropriate for the user's location.
Notify the nearest Agilent Sales and Service Office if the
appropriate power cord is not included with the supply.

Before applying power to the supply, check the label on the
heat sink to make certain that the supply's line voltage option
agrees with the line voltage to be used. If the option does not
correspond to your line voltage, refer to paragraph "LINE
VOLTAGE OPTION CONVERSION" in the service section
before applying power.

Figure 2. Front-Panel Controls and Indicators

Figure 1. Outline Diagram

OPERATING INSTRUCTIONS

INTRODUCTION

This section describes the operating controls and indicators,
turn-on checkout procedures, and other operating consider­ations for the Model E3620A Dual Output Power Supply.

CONTROLS

Line Switch

The LINE pushbutton switch ( , Figure 2) is pushed-in to
turn the supply ON and released (out position) to turn the
supply OFF.

Voltage and Current Metering

Two meter select pushbutton switches ( and ) permit the
output voltage and current of either output (V1 or V2) to be
monitored on the VOLTS/AMPS meter. The V1 and V2 output
select pushbuttons connect the desired output to the meter­ing circuit when the applicable button is pushed in.

Be careful that both METER pushbuttons are not released
(out-position) or pushed in simultaneously.

Voltage Controls

The V1 and V2 voltage controls ( and ) set the voltage
level of the corresponding output. The voltage controls are 10
turn potentiometers.

1-6

TURN-ON CHECKOUT PROCEDURE

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The following steps describe the use of the Model E3620A
front panel controls illustrated in Fi
check that the suppl
cedure or the more detailed performance test of service infor­mation section when the instrument is received and before it
is connected to an
detailed performance test be
section if an

a. Connect line cord to power source and push LINE

switch ( ) in.

b. Push the V1 meter select pushbutton switch ( ) to in-

position to monitor suppl
load connected, var
ran

e and check that the voltmeter responds to the con

trol setting and the ammeter indicates zero.

c. Turn the V1 volta

short the +V1 output terminal ( ) to -V1 terminal ( )
with an insulated test lead. The ammeter should indi­cate a short-circuit output current of minimum 1.0 A +
5% at 25
nals.

d. Push the V2 meter select pushbutton switch to in-

position and repeat steps (b) and (c) for V2 output.

If this brief checkout procedure or later use of the suppl
reveals a possible malfunction, see the service information
section for detailed test, troubleshootin
cedures.

is operational. Follow this checkout pro-

load equipment. Proceed to the more

difficulties are encountered.

the V1 voltage control ( ) over its

e control ( ) fully clockwise and

o

C. Remove the short from the output termi-

ure 2 and serve as a brief

inning in service information

's V1 output voltage. With no

, and adjustment pro-

OPERA TION

The dual outputs of the E3620A can be used individually, in
series, or in parallel. Each output can be floated (up to 240
volts off

the suppl

Overload Protection Circuits

The outputs are individually protected against overload or
short circuit dama
circuits are factor
mum 1 A + 5%. The current limits are set b
the V1 suppl
dia
the output current remains below the current limit settin

round) or, the + or - terminal of either output can be

rounded to the chassis ground terminal which is located on

's front panel.

e by separate current limiting circuits. The

adjusted to limit the output current to mini-

adjusting R63 in

and R34 in the V2 supply (see the schematic

ram). No deterioration of supply performance occurs if

.

Operation Beyond Rated Output

The supply may be able to provide voltages and currents

reater than its rated maximum outputs if the line voltage is at
or above its nominal value. Operation can be extended up to
5% over the rated output without dama
performance can not be
above the rated output of 0 to 25 V at 1 A.

uaranteed to meet specifications

e to the supply, but

Connecting Load

Connect each load to the power supply output terminals usin
separate pairs of connecting wires. This will minimize mutual
couplin
the low output impedance of the suppl
of adequatel
at the load.

Make each pair of connectin
twist or shield them to reduce noise pick-up. If a shield is
used, connect one end of the shield to the power suppl

If load considerations require locatin
terminals at a distance from the power suppl
suppl
tribution terminals b
load should be connected to the remote distribution terminals
separatel

effects between loads and takes full advantage of

. Load wires must be

heavy gauge to maintain satisfactory regulation

wires as short as possible and

round terminal and leave the other end unconnected.

output power distribution

, then the power

output terminals should be connected to the remote dis-

a pair of twisted or shielded wires and each

.

Series Operation

The two outputs (V1 and V2) can be connected in series to
obtain a volta

le output. Each output control (V1 and V2) must be adjusted

sin
in order to obtain the total output volta
internall
capacitors a
plies are connected in series and the output is shorted.

e (up to 50 V) higher than that available from a

e. Diodes connected

across each output protect the supply's output filter

ainst reverse voltages. This could occur if the sup-

Parallel Operation

The V1 and V2 supplies can be connected in parallel to obtain a
total output current
The total output current is the sum of the output currents of the
individual supplies. The output volta
suppl

should be set to the desired output voltage, and the other
set for a slightly larger output voltage. The supply set to

suppl
the lower output volta
while the suppl
ited source, droppin
other suppl
fraction of its rated output current necessar
rent demand.

reater than that available from one supply.

e controls of one power

e will act as a constant voltage source,

set to the higher output will act as a current-lim-

its output voltage until it equals that of the

. The constant voltage source will deliver only that

to fulfill the total cur-

During the actual operation of the V1 and V2 outputs, if a load

e causes the current limit to be exceeded, the OVER-

chan
LOAD LED is li
V2 supplies will protect the load b
imum 1 A + 5%. The V1 and V2 supplies are self restorin

hted. If overload conditions occur, the V1 and

limiting the current to min-

;

that is, when the overload is removed or corrected, the output

e is automatically restored to the previously set value.

volta

LOAD CONSIDERATIONS

This section provides information on operating your suppl
with various types of loads connected to its output.

PULSE LOADING

The power supply will automatically cross over from constant-

e to current-limit operation in response to an increase in

volta
the output current over the preset limit. Althou
limit ma

1-7

be set higher than the average output current, high

h the preset

peak currents (as occur in pulse loadin

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preset current limit and cause crossover to occur and
de

rade performance.

) may exceed the

REVERSE CURRENT LOADING

An active load connected to the supply may actually deliver a
reverse current to the suppl
cycle. An external source can not be allowed to pump current
into the suppl
dama
effects, it is necessar
load resistor so that the supply delivers current through the
entire operatin

without risking loss of regulation and possible

e to the output capacitor of the supply. To avoid these

cle of the load devices.

during a portion of its operatin

to preload the supply with a dumm

OUTPUT CAP ACITANCE

An internal capacitor across the output terminals of the suppl
helps to supply high-current pulses of short duration durin
constant-voltage operation. Any capacitance added exter-

will improve the pulse current capability, but will

nall
decrease the load protection provided b
circuit. A high-current pulse may damage load components
before the avera
the current limitin

e output current is large enough to cause

circuit to operate.

the current limitin

REVERSE VOL TAGE PROTECTION

A diode is connected across the output terminals with reverse

. This diode protects the output electrolytic capacitors

polarit
and the series re
reverse volta
series re
either, diodes are also connected across them. When operat­in
suppl

ulator transistors can not withstand reverse voltage

supplies in parallel, these diodes protect an unenergized

that is in parallel with an energized supply.

ulator transistors from the effects of a

e applied across the output terminals. Since

Figure 3. Reverse Current Loading Solution

1-8

SERVICE INFORMATION

Figure A-1. Block Diagram

PRINCIPLES OF OPERATION

(Block Diagram Overview)

This section presents the principles of operation for the
E3620A Dual Output Power Supply. Throughout this discus­sion, refer to both the block diagram of Figure A-1 and the
schematic of Figure A-10 and Figure A-11.

The E3620A contains two independent power supplies (des­ignated V1 and V2), a common input power circuit, and a
meter circuit that can monitor the output voltage and current
of either supply.

The two primary windings of the power transformer are con­nected in one of three different ways by setting the two slide
switches mounted on the circuit board. These switches select
one of the nominal ac input voltages for which the supply is
designed: 100 V, 115 V, or 230 V. The transformer secondar­ies, together with rectifiers and capacitor filters, provide raw
dc for two output regulator circuits, for two reference and bias

supplies and for a display power supply.

By comparing its output to a high-stability reference, the V1
supply's 0 to 25 V regulator holds its output voltage at the
value determined by the V1 VOLTAGE control of the front
panel. Any error in the actual output as compared to the
desired output is amplified by an operational amplifier and
applied as feedback to control the conduction of a series reg­ulator transistor. As a result, the voltage across the series
transistor varies so as to hold the output voltage constant at
the desired level. The high gain of the voltage comparison
amplifier and the stability of the reference voltage ensure that
input voltage or load current variations have little effect on the
output voltage. The V1 output is protected by a fixed current
limit at minimum 105% of its 1 amp maximum rated output.

A-1

The input ac line volta

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which operates in conjunction with the prere
circuit to rectif
lator minimizes the power dissipated in the series re
elements by controlling the dc level across the input filter
capacitors dependin

the tap switched AC voltage. This preregu-

e is first applied to the preregulator

ulator control

ulatin

on the output voltage.

To achieve this, tap switchin
plished b
diodes(CR5 and CR6) and the prere
This circuit allows the input capacitors to char
discrete volta

When the output volta
re
input capacitors to be char
sar
the brid
to series pass transistor Q2.

The re
V1 output re
Q4) and two brid
capacitors to be char
dependin
dissipation in the series re

The main secondar
three sections (N1, N2, and N3), each of which has a different
turns ratio with respect to the primar
nin
determines whether one, both or none of the TRIAC will be
fired. If neither TRIAC is fired, the brid
CR3) receive an ac input volta
turns (tap 18 and 19 of the power transformer) and the input
capacitors char
fired, input capacitors char
N1+N2 turns. Similarly, if TRIAC Q4 is fired the capacitors are
char
neousl
determined b
power transformer).

The TRIAC control circuit determines which TRIACs are to be
fired b
values a
els. These three reference levels are translated into boundar
lines to allow the output characteristic to be mapped into four
operatin
invisible to the user, are divided into four operatin
(V1, V2, V3, and V4) to minimize the power dissipation in the
series pass transistors. Whenever the output volta
the slopin
the input capacitors char
Fi
result of the other volta

a TRIAC(Q5), a bridge diode (CR4), two

e levels depending on the output required.

ulator control circuit fires the TRIAC Q5 that causes the

for full output of the supply. When the TRIAC is not fired,

e diode CR4 conducts and half the voltage is applied

ulator of the V2 output is, in turn, similar to that of the

ulator except that it has two TRIACs(Q3 and

e diodes(CR2 and CR3) to allow the input

ed to one of four discrete voltage levels

on the output required in order to minimize power

winding of the power transformer has

of each half-cycle of the input ac, the control circuit

e to a corresponding level. If TRIAC Q3 is

ed by N1 + N3. Finally, if all TRIACs are fired simulta-

, input capacitors charge to its highest voltage level

N1 + N2 + N3 turns (tap 17 and 20 of the

monitoring the output voltage and comparing these

ainst a set of three internally derived reference lev-

regions (Figure A-2). The boundary lines, which are

V1 line, the control circuit inhibits two TRIACs and

ure A-2 indicates the windings that are connected as a

of the V1 output is accom-

ulator control circuit.

e to one of two

e exceeds the reference level, the pre-

ed to the voltage which is neces-

ulator transistor Q1.

winding. At the begin-

e diodes (CR2 and

e that is determined by N1

e to the voltage determined b

regions

e is below

e to a voltage determined by N1.

e decisions.

Figure A-2. Output Power Plot

Diode CR13 and CR19 are connected across the output
terminals in reverse polarit

tic capacitor and the series regulator transistors from

electrol
a reverse volta

Two meter pushbutton switches select which suppl
V2) has its output volta
panel meters.

e applied across the output terminals.

. They protect the output

(V1 or

e and current indicated on the front

MAINTENANCE

INTRODUCTION

This section provides performance test, troubleshooting infor­mation, and adjustment and calibration procedures. The fol-

operation verification tests comprise a short procedure

lowin
to verif

that the power supply is performing properly, without

all specified parameters.

testin

If a fault is detected in the power suppl
performance check or durin
the troubleshootin
form an
returnin
performance check to ensure that the fault has been properl
corrected and that no other faults exist.

necessary adjustments and calibrations. Before

the power supply to normal operation, repeat the

procedures. After troubleshooting, per-

normal operation, proceed to

Test Equipment Required

Table A-1 lists the equipment required to perform the various
procedures described in this section.

Operation Verification Tests

The following tests assure that the power supply is per-

properly. They do not, however, check all the speci-

formin
fied parameters tested in the complete performance test
described below. Proceed as follows:

while making the

The reference and bias supplies of each suppl
operational amplifiers and provide reference and bias volt­a

es for the output regulators. The display power circuit pro-

vides volta

e which is used by the A/D converter and display.

power the

a. Perform turn-on checkout procedure
b. Perform the load re

the followin

A-2

ulation performance tests given in

paragraphs.

iven in page 1-7.

Table A-1. Test Equipment Required

TYPE REQUIRED CHARACTERISTICS

Oscilloscope

Sensitivity : 100BµV
Bandwidth : 20 MHz/100 MHz

RMS Voltmeter True rms, 20 MHz bandwidth

Sensitivit

y : 1 mV

Accuracy : 5%

Multimeter Resolution : 100 nV

Accuracy : 0.0035%

Electronic Load Voltage Range : 240 Vdc

Current Range : 10 Adc
Open and short switches
Transient on/off

Resistive Loads (R
Current Sampling

Resistor (Shunt)
Variable Voltage

)

L

25BΩB5% 100 W

0.1BΩ 0.1% 3 W

Range : 85-130 and 200-260 Volts Vary ac input.

Auto Transformer

Line Voltage Option Conversion

To convert the supply from one line voltage option to another,
the following three steps are necessary:

a.After making certain that the line cord is disconnected

from a source of power, remove the top cover from the
supply and set the two sections of the line voltage selec­tor switch for the desired line voltage (see Figure A-3).

b.Check the rating of the installed fuse and replace it with

the correct value, if necessary. For Option OE3, use a
slow-blow 1 amp fuse. For standard and Option OE9, use
a slow-blow 2 amp fuse.

c.Mark the instrument clearly with a tag or label indicating

the correct line voltage to be used.

USE

Display transient response and ripple

RECOMMENDED

MODEL

Agilent 54503A

and noise waveforms.
Measure rms ripple and noise

voltage.

Measure dc voltages. Agilent 34401A

Measure load and line re

gulation. Agilent 6063A

Measure ripple and noise.
Measure output current.

Before applying power to the supply, make certain
that its line voltage selector switch (S1) is set for the
line voltage to be used. (See CAUTION notice in
operating section for additional information on S1.)

General Measurement Techniques

Connecting Measuring Devices.

when measuring load regulation, ripple and noise, and transient
response time of the supply, measuring devices must be con­nected as close to the output terminals as possible. A measure­ment made across the load includes the impedance of the leads
to the load. The impedance of the load leads can easily be sev­eral orders of magnitude greater than the supply impedance and
thus invalidate the measurement. To avoid mutual coupling
effects, each measuring device must be connected directly to
the output terminals by separate pairs of leads.

To achieve valid results

Figure A-3. Line Voltage Selector (set for 115 Vac)

PERFORMANCE TESTS

The following paragraphs provide test procedures for verify­ing the power supply's compliance with the specifications of
Table 1. Proceed to the troubleshooting procedures if you
observe any out of specification performance.

When performance measurements are made at the front ter­minals (Figure A-4) the load should be plugged into the front
of the terminals at (B) while the monitoring device is con­nected to a small lead or bus wire inserted through the hole in
the neck of the binding post at (A). Connecting the measuring
device at (B) would result in a measurement that includes the
resistance of the leads between the output terminals and the
point of connection.

Selecting Load Resistors. Power suppl

y specifications are
checked with a full load resistance connected across the sup­pl

y output. The resistance and wattage of the load resis­tor,therefore, must permit operation of the supply at its rated
output voltage and current. For example, a supply rated at 25

A-3

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and that the current limit circuits function, proceed as follows:

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Figure A-4. Front Panel Terminal Connections

volts and 1 amp would require a load resistance of 25 Ω at
the rated output volta
would have to be at least 25 watts.

Electronic Load. Some of the performance test procedures
require to use an electronic load to test the suppl
accuratel
than a load resistor. It eliminates the need for connectin
resistors or rheostats in parallel to handle the power, and it is
much more stable than a carbon-pile load. It is easier to
switch between load conditions as required for the load re
lation and load transient response tests.

Output Current Measurement. For accurate output current
measurements, a current samplin
inserted between the load and the output of the suppl
simplif
tor should be connected to the same output terminal of the
suppl
is then placed across the samplin
current is calculated b
plin
series combination should be equal to the full load resistance
as determined in the precedin
value of the samplin
the full load resistance, the value of the samplin
be ignored. The meter shunt recommended in Table A-1, for
example, has a resistance of onl
ne
Fi
rent throu
wire leadin
are made as close as possible to the resistance portion itself.

. An electronic load is considerably easier to use

rounding problems, one end of this sampling resis-

which will be shorted to ground. An accurate voltmeter

resistor by its ohmic value. The total resistance of the

lected when calculating the load resistance of the supply.

ure A-5 shows a four terminal meter shunt. The load cur-

h a shunt must be fed from the extremes of the

to the resistor while the sampling connections

e. The wattage rating of this resistor

quickly and

resistor should be

. To

resistor and the output

dividing the voltage across the sam-

paragraphs. Of course, if the

resistor is very low when compared to

resistor ma

100 mΩ and can be

Rated Output Volta

a. With no loads connected: turn on the supply and push the

V1 METER switch in. Connect a DVM between the V1 +
and - terminals and set V1 VOLTAGE control until front
panel voltmeter indicates 17.00 volts.

b. Check the DVM indication. It should be within ±(0.5% + 2

counts) of the front panel voltmeter indication (16.90 to

17.10 V).

c. Set V1 VOLTAGE control clockwise until front panel volt-

meter indicates 25.0 volts.

d. DVM should indicate 25 volts ±(0.5% + 2 counts) (24.675

V to 25.325 V).

e. Repeat steps (a) throu

Rated Output Current and Ammeter Accurac

f. Connect the test setup shown Figure A-6 to the V1 sup-

pl

's + and - output terminals.

. Push the V1 METER switch in to monitor the V1 supply's

output current.

h. Close the load switch and adjust V1 VOLTAGE control

u-

until front panel ammeter indicates 1.000 A.

i. Check that DVM indicates a volta

rent samplin
amp ±(0.5% + 2 counts) (0.993 A to 1.007 A).

j. Open the load switch and repeat steps (f) throu

the V2 suppl

resistor that corresponds to a current of 1

.

e and Voltmeter Accurac

h (d) for the V2 supply.

e drop across the cur-

h (i) for

Figure A-6. Output Current, Test Set Up

k. Disconnect all loads from the suppl
l. Connect the test setup shown in Fi

suppl

's + and - output terminals. Substitute a short for RL

and leave the load switch open.

m. Push the V1 METER switch in and adjust the V1 VOLT-

AGE control full

n. Close the load switch and determine the current flow

Figure A-5. Current Sampling Resistor Connections

Rated Output, Meter Accuracy, and Current Limit

To check that all supplies will furnish their maximum rated output
volta

e and current, that the front panel meters are accurate,

o. Open the load switch and repeat steps (k) throu

A-4

h the current sampling resistor RS by measuring its

throu
volta

e drop with the DVM. The current should be mini-

mum 1 A + 5%.

the V2 suppl

Current Limit

clockwise.

.

.
ure A-6 to the V1

h (n) for

Load Regulation (Load Effect)

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Definition: The chan
put volta
open circuit to the value that
current (or vice versa).

e resulting from a change in load resistance from

e, E

, in the static value of dc out-



OUT

ields maximum rated output

RMS Measurement

The rms measurement is not an ideal representation of the
noise, since fairl
could be present in the ripple and not appreciabl
the rms value.

high output noise spikes of short duration

increase

To check the load re
a. Connect the test equipment across the output of the V1 sup-

as shown in Figure A-7. Operate the electronic load in

pl
constant current mode and set its current to 1.000 A.

b. Turn on the suppl

adjust its volta
c. Record the volta
d. Operate the electronic load in open (input off) mode and

recheck the DVM indication after readin

be within 0.01% plus 2 mV of the readin
e. Repeat steps (a) throu

ulation:

. Push the V1 METER switch in and

e to 25.0 volts.

e indicated on the DVM.

settles. It should

in step (c).

h (d) for the V2 supply.

Figure A-7. Basic Test Setup

Line Regulation (Source Effect)

Definition: The chan

put volta
minimum to a maximum value (±10% of nominal volta

To check the line re
a. Connect a variable autotransformer between the input

b. Connect the test equipment across the output of the V1 sup-

c. Adjust the autotransformer for a low line input (-10% of

d. Turn on the power. Push the V1 METER switch in and

e. Adjust the autotransformer for hi

f. Repeat steps (b) throu

e resulting from a change in ac input voltage from a

power source and the power suppl

as shown in Figure A-7. Operate the electronic load in

pl

constant current mode and set its current to 1.000 A.

nominal volta

adjust the output of the suppl

the DVM indication.

of nominal volta

should be within 0.01% plus 2 mV of the readin

e, E

ulation:

e).

e) and recheck the DVM indication. It

, in the static value of dc out-



OUT

line plug.

to 25.0 volts, and record

h line voltage input (+10%

h (e) for the V2 supply.

e).

in step (d).

Ripple and Noise(Normal Mode Voltage)

Definition: Ripple and noise are measured in the rms or peak-

to-peak value over a 20 Hz to 20 MHz bandwidth. Fluctuations
below the lower frequenc

limit are treated as drift.

To measure the ripple and noise of the rms value on each
output suppl
a. Connect the test equipment across the output of the V1

suppl
b. Turn on the suppl
c. Adjust the output of the V1 suppl
d. Check that the rms noise volta

ter is less than 0.35 mV.
e. Repeat steps (a) throu

output:

as shown in Figure A-8.

and push the V1 METER switch in.

to 25.0 volts.

e at the true rms voltme-

h (d) for the V2 supply.

Figure A-8. Ripple and Noise rms Measurement Test

Setup

Peak-to-Peak Measurement

The peak-to-peak measurement is particularly important for
applications where noise spikes could be detrimental to a
sensitive load, such as lo

To measure the ripple and noise of the peak-to-peak value on
each output suppl
a. Connect the test equipment across the output of the V1

suppl

as shown in Figure A-8, but replace the true rms

voltmeter with the oscilloscope.
b. Turn on the suppl
c. Adjust the output of the V1 suppl
d. Set the oscilloscope to AC mode and bandwidth to 20 MHz.
e. Check that the peak-to-peak noise is less than 1.5 mV.
f. Repeat steps (a) throu

ic circuitry.

output:

and push the V1 METER switch in.

to 25.0 volts.

h (e) for the V2 supply.

Common Mode Current (CMI)

Definition : Common mode current is that ac current compo-

nent which exists between an
and chassis

To measure the common mode current:
a. Connect the full load for the V1 output terminal.
b. Connect a 100 kΩ resistor(R

in parallel between V1 - terminal and chassis

round.

or all supply or output lines

) and a 2200 pF capacitor

S

round.

A-5

c. Connect theDVM across R

. Operate theDVM in ac volt-

S

age mode.
d. Turn on the supply.
e. Record the voltage across R

dividing this voltage by R

and convert it to current by

S

.

S

f. Check that the current is less than 1 µA.
g. Repeat steps (a) through (f) for the V2 supply.

Load Transient Response Time

Definition : This is the time for the output voltage to return to

within a specified band around its voltage following a change
from full load to half load or half load to full load.

To measure the load transient response time:
a. Connect the test equipment across the output of the V1

supply as shown in Figure A-7, but replace the DVM with

the oscilloscope. Operate the electronic load in constant

current mode.
b. Turn on the supply and push the V1 METER switch in.
c. Turn up V1 output voltage to 25.0 volts.
d. Set the electronic load to transient operation mode

between one half of supply's full rated value and supply's

full rated value at a 1 kHz rate with 50% duty cycle.
e. Set the oscilloscope for ac coupling, internal sync and

lock on either the positive or negative load transient.

f. Adjust the oscilloscope to display transients as shown in

Figure A-9.

g. Check that the pulse width (t

) of the transients at 15

2-t1

mV from the base line is no more than 50 µsec as shown.

h. Repeat steps (a) through (g) for the V2 supply.

Stability (Drift)

Definition: The change in output voltage (dc to 20 Hz) for the

first 8 hours following a 30-minute warm-up period with con­stant input line voltage, constant load resistance and constant
ambient temperature.

To measure the stability:
a. Connect the test equipment across the output of the V1

supply as shown in Figure A-7.

b. Operate the electronic load in constant current mode and

set its current to 1.000 A.
c. Turn on the supply and push the V1 METER switch in.
d. Turn up V1 output voltage to 25.0 volts as read on the

digital voltmeter.
e. After a 30-minute warm-up, note the voltage on DVM.
f. The output voltage reading should deviate less than 0.1%

plus 5 mV from the reading obtained in step (e) over a

period of 8 hours.
g. Repeat steps (a) through (f) for the V2 supply.

Figure A-9. Load Transient Response Time Waveform

A-6

TROUBLESHOOTING

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Before attempting to troubleshoot the power supply, ensure
that the fault is with the suppl
piece of equipment. You can determine this without removin
the covers from the power supply by using the appropriate
portions of the "Performance Tests" para

Before applying power to the supply, make certain
that its line volta
line volta

e selector switch (S1) is set for the

e to be used.

Initial Troubleshooting Procedure

If a malfunction is found, follow the steps below:
a. Disconnect input power from the suppl

loads from the output.

b. Table A-2 lists the s

several possible troubles. If the s
listed, make the recommended checks.

SYMPTOM CHECK - PROBABLE CAUSE

Hi

h ripple a. Check operating setup for ground loops.

and not with an associated

raph.

and remove all

mptoms and probable causes of

mptoms is one of those

Table A-2. Miscellaneous Troubles

b. Check main rectifiers(CR2, CR3, CR4) for open.
c. Suppl

may be operating in current limit mode. Check current limit adjustment, steps (l) thru (n)

on pa

e A-4.

c. If none of the s

Table A-3. This table provides an initial troubleshootin
procedure that also directs
cedures which follow it.

The numbered test points referred to in the troubleshootin
procedures are identified on the circuit schematic at the rear
of the manual.

mptoms of Table A-2 apply, proceed to

ou to the more detailed pro-

Open Fuse Troubleshooting

Although transients or fatigue can cause a fuse to blow, it is a

ood idea to inspect the unit for obvious shorts such as dam-

a

ed wiring, charred components, or extraneous metal parts
or wire clippin
before replacin
ment fuse depends on the line volta
ment: for Option OE3, use a slow-blow 1 amp fuse and
standard and Option OE9, use a slow-blow 2 amp fuse.

s in contact with circuit board conductors
the fuse. The rating of the correct replace-

e option of the instru-

Will not current limit Check for open OR­Poor load and line re

Oscillation or poor transient
response time

Excessive heat a. Check prere

Output Volta
each output

ulation a. Check bias and reference voltages, Table A-4.

e clamped for

b. Check main rectifiers and filters for opens.
a. Hi

h frequency oscillations (above 50 kHz) can be caused by an open C13 or C35.

b. A defective output capacitor (C10 or C29) can cause oscillations in one of man

ran

es.

c. Oscillation onl

b. Check Q3, Q4 and Q5 for short.
Check preregulator control circuit. Refer to Table A-7 and Table A-8.

ate diodes (CR9, CR21) or defective current limit amplifiers (U10, U19).

in the current limiting mode can be caused by an open C34 or C12.

ulator control circuit. Refer to Table A-7 and Table A-8.

Table A-3. Initial Troubleshooting Procedure

STEP ACTION RESPONSE NEXT ACTION

1 Check output volta

and V2 supplies.

e of V1

a. Zero volts

b. Output volta

her than ratin

hi

e lower or

a. Check ac line fuse (F1). If blown, proceed to "Open

Fuse Troubleshootin
bias and reference volta

b. Check bias and reference volta

" paragraph. If not blown, check

es (Table A-4).

frequency

es (Table A-4).

A-7

Table A-4. Output Voltage Bias and Reference Voltage Check

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STEP ACTION RESPONSE NEXT ACTION

1 Check +12V bias. a. Normal (+12V ± 5%)

b. Volta

c. Output volta

2 Check -12V bias. a. Normal (-12V ± 5%)

b. Volta

c. Volta

3 Check +5V reference. a. Normal (+5V ± 2%)

b. Volta

c. Volta

4 Check -5V reference. a. Normal (-5V ± 2%)

b. Volta

c. Volta

e high

hi

her than ratin

e high

e low

e high

e low

e high

e low

e lower or

Table A-5. V1 Supply Troubleshootin

a. Proceed to step (3).
b. Check U13(for V2 output) or U23(for V1 output) for

short.

c. Check U13(for V2 output) or U23(for V1 output) for

open.

Note: A short within U4,BU5, U6, U7, U9, U10, U18 or

U19 can cause low +12V or -12V bias volta

a. Proceed to step (4).
b. Check U14(for V2 output) or U20(for V1 output) for

open.

c. Check U14(for V2 output) or U20(for V1 output) for

short.

a. Proceed to V1 suppl
b. Check U11(for V2 output) or U22(for V1 output) for

open.

c. Check U11(for V2 output) or U22(for V1 output) for

short.

a. Proceed to V1 suppl
b. Check U12(for V2 output) or U21(for V1 output) for

open.

c. Check U12(for V2 output) or U21(for V1 output) for

short .

troubleshooting Table A-5.

troubleshooting Table A-5.

es.

SYMPTOM STEP - ACTION RESPONSE PROBABLE CAUSE

Hi

h output voltage

her than rating)

(hi

Low output volta
(lower than ratin

1. Attempt to turn off Q2 b

2. Measure volta

1. Attempt to turn on Q2 b

e

)

2. Attempt to turn off of

3. Eliminate current limit

4. Measure volta

emitter-to-col-

shortin
lector of Q10.

base of Q10.

disconnectin
Q10.

shorting point

Q10 b

to +12 V.

circuit as a source of
trouble b
anode of CR9.

3 of U10.

e at

emitter of

disconnecting

e at pin

a. Output volta
b. Output volta

a. Measured volta

volt.

b. Measured volta

volt.

a. Output volta
b. Output volta

a. Output volta
b. Output volta

a. Output volta
b. Output volta

a. Measured volta

+0.7V.

b. Measured volta

c. Measured volta

-0.7V

e remains high.
e decreases.

e is more than 0

e is less than 0

e remains low.
e increases.

e remains low.
e increases.

e increases.
e remains low.

e is near

e is zero volt.

e is near

a. Q1 shorted.
b. Remove short and proceed to step

(2).

a. Check for open CR8 or R48 and

check for defective U10B.

b. Check for defective Q6.

a. Q1 open.
b. Re-connect the emitter lead and

proceed to step (2).
a. Q6 shorted.
b. Remove short and proceed to step

(3).
a. Check for U10A defective.
b. Reconnect lead and proceed to

step (4).

a. Check for defective U10B.

b. Check for shorted CR14 and

CR15.
c. Check for shorted R48, or leaky or

shorted C9.

A-8

Table A-6. VT Supply Troubleshootin

g

g

g

y

g

g

g

g

g

g

g

g

y

g

y

y

g

g

g

g

g

g

g

g

g

g

g

g

g

g

g

g

g

g

g

g

g

g

g

g

g

g

g

g

g

SYMPTOM STEP - ACTION RESPONSE PROBABLE CAUSE

h output voltage

Hi

her than rating)

(hi

Low output volta
(lower than ratin

1. Attempt to turn off Q1 b

2. Measure volta

1. Attempt to turn on Q1 b

e

)

2. Attempt to turn off of Q6

3. Eliminate current limit

4. Measure volta

emitter-to-col-

shortin
lector of Q6.

base of Q6.

disconnectin
Q6.

shorting point

b

to +12 V.

circuit as a source of
trouble b
anode of CR9.

3 of U10.

disconnecting

e at

emitter of

e at pin

a. Output volta
b. Output volta

a. Measured volta

volt.

b. Measured volta

volt.

a. Output volta
b. Output volta

a. Output volta
b. Output volta

a. Output volta
b. Output volta

a. Measured volta

+0.7V.

b. Measured volta

c. Measured volta

-0.7V

e remains high.
e decreases.

e is more than 0

e is less than 0

e remains low.
e increases.

e remains low.
e increases.

e increases.
e remains low.

e is near

e is zero volt.

e is near

a. Q1 shorted.
b. Remove short and proceed to step

(2).

a. Check for open CR8 or R48 and

check for defective U10B.

b. Check for defective Q6.

a. Q1 open.
b. Re-connect the emitter lead and

proceed to step (2).
a. Q6 shorted.
b. Remove short and proceed to step

(3).
a. Check for U10A defective.
b. Reconnect lead and proceed to

step (4).

a. Check for defective U10B.

b. Check for shorted CR14 and

CR15.
c. Check for shorted R48, or leaky or

shorted C9.

Table A-7. V1 Preregulator/Control Circuit Troubleshootin

STEP ACTION RESPONSE PROBABLE CAUSE

Set output volta

1 Measure the volta

2 Measure the volta

e at 16V.

e for pin 7 of U18. a. Measured voltage is -12V.

e for pin 1 of U3. a. Measured voltage is near +1V

b. Measured volta

+11.3V.

b. Measured volta

e is near

e is near 0V.

a. Proceed to step (2).
b. Check for defective U18B.

a. Check for defective U3 or Q5.
b. Check for open Q9 or R6.

Table A-8. V2 Preregulator/Control Circuit Troubleshootin

STEP ACTION RESPONSE PROBABLE CAUSE

Set output volta

1 Measure the volta

2 Measure the volta

3 Measure the volta

4 Measure the volta

7 of U7.
Set output volta

5 Measure the volta

e to 10V ± 1V.

e for pin 1 of U4. a. High voltage(+0.7 V).

e for pin 1 of U6. a. Low voltage(-12 V).

e for pin 1 of U7. a. High voltage(+12 V).

e from pin 6 to pin

e to 19V ± 1V.

e for pin 7 of U4. a. High voltage(+0.7 V).

b. Low volta

b. Hi

b. Low volta
a. Measured voltage is positive.

b. Measured volta

b. Low volta

e(0 V).

h voltage(+12 V).

e(-12 V).

e(0 V).

e is negative.

a. U1 or Q3 defective.
b. Proceed to step 2.

a. U4 defective.
b. Proceed to step 3.

a. U6 defective.
b. Proceed to step 4.

a. U7 defective.
b. U5 defective.

a. U2 or Q4 defective.
b. Proceed to step 6.

A-9

g

g

g

g

g

g

Table A-8. V2 Preregulator/Control Circuit Troubleshooting (Cont’d)

6 Measure the volta

7 Measure the volta

8 Measure the volta

U7.

e for pin 14 of U6. a. Low voltage(-12 V).

e for pin 14 of U7. a. High voltage(+12 V).

e from pin 8 to pin 9 of

b. Hi

h voltage(+12 V).

b. Low volta
a. Measured voltage is positive.

b. Measured volta

e(-12 V).

e is negative.

a. U4 defective.
b. Proceed to step 7.

a. U6 defective.
b. Proceed to step 8.

a. U7 defective.
b. U5 defective.

A-10

ADJUSTMENT AND CA LIBRATION

Current Limit Adjustment

To adjust the current limit circuit in the V1 or V2 supply, pro­ceed as follows:
a. Turn the current limit adjustment pot (R63 for V1 supply

or R34 for V2 supply) to fully counter clockwise.

b. Connect the test setup shown in Figure A-6 to the output

of the supply to be adjusted. Substitute a short for R
leave load circuit switch open.

c. Turn on the supply and set the VOLTAGE control for max-

imum output(fully clockwise).

d. Close load switch and adjust the current limit pot (R63 or

R34) until the DVM indicates a voltage drop across the
shunt of 0.1 V + 5% (0.105 V).

Meter Calibration

Vol tme ters. To calibrate voltmeter, proceed as follows:
a. Connect DVM across V1 + and - output terminal.
b. Turn on the supply and push V1 METER switch in.
c. Set the output voltage to 17.00 volts, and adjust R16 on

the display board until front panel VOLTS display reads
exactly DVM value. Next, set the output voltage to 25.0
volts and adjust R17 on the display board until front panel
VOLTS display reads exactly DVM value.

d. To calibrate the voltmeter for V2 output, push V2 METER

switch in and connect DVM across V2 + and - output ter­minal.

e. Set the output voltage to 15.00 V and then adjust R81 on

the main board until front panel VOLTS display reads
exactly DVM value.

Ammeters. To calibrate ammeter for V1 and V2 supplies,
proceed as follows:
a. Connect the test setup shown in Figure A-6 to the output

of the V1 supply. Substitute a short for R
circuit switch open.

b. Push V1 METER switch in and turn V1 VOLTAGE control

fully clockwise.

c. Close the load switch and adjust R5 on the display board

until front panel AMPS display reads exactly DVM value
divided by R

d. To calibrate the ammeter for V2 output, repeat step (a) to

the V2 supply. Select V2 METER switch and turn V2
VOLTAGE control fully clockwise.

e. Adjust R80 on the main board until front panel AMPS dis-

play reads exactly DVM value divided by Rs.

.

S

and leave load

L

and

L

REPLACEABLE PARTS

INTRODUCTION

This section contains information for ordering replacement
parts. Table A-11 lists parts by reference designators and pro­vides the following information:

a. Reference designators. Refer to Table A-9.
b. Agilent Technologies Part Number.
c. Total quantity used in that assembly.
d. Description.
e. Manufacturer's supply code number. Refer to Table A-

10 for manufacturer's name and address.

f. Manufacturer's part number or type.

Mechanical and miscellaneous parts are not identified by ref­erence designator.

ORDERING INFORMATION

To order a replacement part, address order or inquiry to your
local Agilent Technologies sales office (see lists at rear of this
manual for addresses). Specify the following information for
each part: Model, complete serial number of the power sup­ply; Agilent Technologies part number; circuit reference des­ignator; and description.

Table A-9. Reference Designators

A Assembly
C Capacitor
CR Diode
DS Signaling Device(light)
FFuse
G Pulse Generator
JJack
L Inductor
Q Transistor
RResistor
SSwitch
T Transformer
TP Test Point
VR Zener Diode
U Integrated Circuit
WWire

Table A-10. Code List of Manufacturers

CODE MANUFACTURER ADDRESS

01295 Texas Instruments Inc, Semicon Comp Div. Dallas, TX

14936 General Instruments Corp, Semicon Prod Hicksville, N.Y.

27014 National Semiconductor Corporation Santa Clara, CA

28480 Agilent Technologies Palo Alto, CA

04713 Motorola Semiconductor Products Phoenix, AZ

32997 Bourns Inc. Riverside, CA

A-11

Table A-11. Replaceable Parts List

REFERENCE

DESIGNATE

Q1,2 1854-0611 2 TRANSISTOR NPN 2N6056 SI DARL TO 3 04713 2N6056

R48,74 2100-4503 2 RES-VAR 10K 5% 10-TURN WW 32997 3590S-A7-103

E3631-20012 2 BINDING POST BLACK 28480

C24 0180-4360 1 CAP-FXD 1000UF +- 20% 25V AL-ELECTLT 28480

C22,23,31 0180-4085 3 CAP-FXD 330UF +-20% 35V AL-ELECTLT 28480

C19,20,25,26,32,33 0160-7449 6 CAP-FXD .33UF +-10% 50V POLYP-MET 28480

C17,18,27,28,40,41 0180-3970 6 CAP-FXD 1UF +-20% 50V AL-ELECTLT 28480

C10,21,29,30 0180-4355 4 CAP-FXD 470UF 50V +-20% AL-ELECTLT 28480

C42 0160-4065 1 CAP-FXD 0.1UF +-20% 250V PPR-MET 28480

C7,8,11,12,15,16,34,36,39 0160-4832 9 CAP-FXD 0.01UF +-10% 100V CER 28480

C1,2,5,6 0180-3657 4 CAP-FXD 1000UF +-20% 63V AL-ELECTLT 28480

C3,4 0160-6225 2 CAP-FXD 0.33UF +-10% 250V POLYP-MET 28480

C9,37 0180-3769 2 CAP-FXD 6.8UF +-10% 35V TA 28480

C13,14,35,38 0160-4801 4 CAP-FXD 100PF +-5% 100V CER 28480

C43,44 0160-7049 2 CAP-FXD 4700PF +-20% 250V CER X5V 28480

R51 0699-2715 1 RESISTOR-FUSE 1OHM +-5%; 0.5W @70 28480

R54 0757-0401 1 RESISTOR 100 +-1%; 0.125W TF TC=0 +-100 28480

R52 0698-4440 1 RESISTOR 3.4K +-1%; 0.125W TF TC=0 +-100 28480

R53 0698-4425 1 RESISTOR 1.54K +-1%; 0.125W TF TC=0 +-100 28480

R18,19,20,62 0698-8824 4 RESISTOR 562K +-1% 0.125W TF TC=0 +-100 28480

R13,14,15,16,17,27,36,37,61 0757-0442 9 RESISTOR 10K +-1%; 0.125W TF TC=0 +-100 28480

Agilent PART

NUMBER

8120-8767 1 POWER CORD FOR STD,0E9 28480

8120-8768 1 POWER CORD FOR 0E3 28480

E3620-60001 1 MAIN BODY ASSY (STD, 0E9) 28480

E3620-60005 1 MAIN BODY ASSY (0E3) 28480

5041-8622 1 COVER 28480

0371-3806 1 KEY CAP - WHT 28480

E3630-40007 2 KEY CAP - FLINT GRAY 28480

0340-0140 2 INSULATOR - TRANSISTOR MICA 28480

0340-0168 8 INSULATOR BUSHING 28480

E3620-60003 1 HEAT SINK ASSY-STD,0E9(115V, 100V) 28480

E3620-60006 1 HEAT SINK ASSY-0E3(230V) 28480

1252-4214 1 AC INLET SOCKET 28480

2110-0702 1 FUSE 2A 250V NTD (STD,0E9) 28480

2110-0457 1 FUSE 1A 250V NTD (0E3) 28480

5022-1632 1 HEATSINK-DIECASTING 28480

E3620-60004 1 FRONT PANEL ASSY 28480

E3620-60009 1 DISPLAY BOARD ASSY 28480

E3631-20011 2 BINDING POST RED 28480

E3631-20013 1 BINDING POST GREEN 28480

2950-0144 5 NUT- BINDING POST 28480

5041-8621 2 KNOB 28480

E3620-60002 1 MAIN BOARD ASSY 28480

E3620-20001 1 PCB MAIN FOR E3620A 28480

Q'TY DESCRIPTION MFR.

CODE

MFR. P/N

A-12

Table A-11. Replaceable Parts List(cont'd)

REFERENCE

DESIGNATE

R41,49,70,77,79 0757-0280 5 RESISTOR 1K +-1% 0.125W TF TC=0 +-100 28480

R45,65,66 0698-4055 3 RESISTOR 1K +-.25% 0.125W TF TC=0 +-100 28480

R50,73 0757-0283 2 RESISTOR 2K +-1%; 0.125W TF TC=0 +-100 28480

R6 0757-1092 1 RESISTOR 287 +-1%; 0.5W TF TC=0 +-100 28480

R29,58,69 0698-4002 3 RESISTOR 5K +-1% 0.125W TF TC=0 +-100 28480

R1,8 0811-2188 2 RESISTOR 5K +-5% 3W PWI 20PPM 28480

R28,30,56,64 0757-1097 4 RESISTOR 1.2K +-1% 0.125W TF TC=0 +-100 28480

R3,5 0757-0812 2 RESISTOR 432 +-1%; 0.5W TF TC=0 +-100 28480

R57 0698-3167 1 RESISTOR 25K +-1% 0.125W TF TC=0 +-100 28480

R47,71 0757-0465 2 RESISTOR 100K +-1% 0.125W TF TC=0 +-100 28480

R32,75 0698-3430 2 RESISTOR 21.5 +-1% 0.125W TF TC=0 +-100 28480

R59 0757-0200 1 RESISTOR 5.62K +-1% 0.125W TF TC=0 +-100 28480

R43,78 0757-0405 2 RESISTOR 162 +-1% 0.125W TF TC=0 +-100 28480

R2,4,7 0757-0346 3 RESISTOR 10 +-1% 0.125W TF TC=0 +-100 28480

R34,63 2100-2497 2 RESISTOR-TRMR 2K 10% TKF TOP-ADJ 1-TRN 28480

R42,76 0757-0278 2 RESISTOR 1.78K +-1% 0.125W TF TC=0 +-100 28480

R44,46 0757-0420 1 RESISTOR 750 +-1% 0.125W TF TC=0 +-100 28480

R35,55 0811-3861 2 RESISTOR 1.78 +-1% 5W PWN TC=0 +-90 28480

R33,72 0698-6250 2 RESISTOR 2.5K +-1% 0.125W TF TC=0 +-100 28480

R31,68 0698-4429 2 RESISTOR 1.87K +-1% 0.125W TF TC=0 +-100 28480

R9,10,11,12 0698-3160 4 RESISTOR 31.6K +-1% 0.125W TF TC=0 +-100 28480

R67 0699-0069 1 RESISTOR 2.15M +-1% 0.125W TF TC=0 +-100 28480

R21,22,23,38 0698-0084 4 RESISTOR 2.15K +-1% 0.125W TF TC=0 +-100 28480

R24,25,26 0698-4473 3 RESISTOR 8.06K +-1% 0.125W TF TC=0 +-100 28480

R39 0698-4443 1 RESISTOR 4.53K +-1% 0.125W TF TC=0 +-100 28480

R40 0698-3450 1 RESISTOR 42.2K +-1% 0.125W TF TC=0 +-100 28480

R60 0698-3136 1 RESISTOR 17.8K +-1% 0.125W TF TC=0 +-100 28480

R80,81 2100-0554 2 RESISTOR-TRMR 500 10% TKF TOP-ADJ 1-TRN 28480

U16 1826-0144 1 IC V RGLTR-FXD POS 4.8/5.2V TO 220 PKG 04713 MC7805CT

U15 1826-0445 1 IC V RGLTR-FXD NEG -4.8/-5.2V TO 220 PKG 04713 MC7905CT

U13,23 1826-0147 2 IC V RGLTR-FXD-POS 11.5/12.5V TO-220 PKG 04713 MC7812CT

U14,20 1826-0221 2 IC V RGLTR-FXD-NEG -11.5/-12.5V TO-220 04713 MC7912CT

U1,2,3 1990-1659 3 IC OPTO-ISOLATOR LED-TRIAC IF=100MA-MAX 14936 MCP3020Z

U4,9,18 1826-0412 3 IC COMPARATOR PRCN DUAL 8 PIN DIP-P 27014 LM393N

U10,19 1826-1075 2 IC OP AMP GP DUAL 8 PIN DIP-P 27014 LF442CN

U8,11,12,17,21,22 1826-1297 6 IC V RGLTR-V-REF-FXD 4.8/5.2V TO-92 PKG 27014 LM336BZ-5.0

U6,7 1826-0138 2 IC COMPARATOR GP QUAD 14 PIN DIP-P 27014 LM339

U5 1826-0665 1 IC OP AMP LOW-BIAS-H-IMPD QUAD 14 PIN 27014 LF347BN

Q9 1853-0281 1 TRANSISTOR PNP 2N2907 SI TO-18 PD=400MW 04713 2N2907A

Q6,10 1853-0590 2 TRANSISTOR PNP 2N4036 SI TO-5 PD=1W 04713 MM5007

Q7,8 1854-0477 2 TRANSISTOR NPN 2N2222A SI TO-18 PD=500MW 04713 2N2222A

CR16,20 1906-0284 2 DIODE-FW BRIDGE 100V 1A 14936 DF01

CR2,3,4 1906-0351 3 DIODE-FW BRIDGE 100V 2A 14936 2KBP02M

CR1,5,6,7,13,17,18,19 1901-1149 8 DIODE-PWR RECT 400V 1A 50NS DO-41 14936 UF4004

Q3,4,5 1884-0361 3 THYRISTOR-TRIAC TO-220 28480 BTA06-600B

Agilent PART

NUMBER

Q'TY DESCRIPTION MFR.

CODE

MFR. P/N

A-13

Table A-11. Replaceable Parts List(cont'd)

REFERENCE

DESIGNATE

CR8,9,10,11,12,14,15,21,22,
23,24,25,26,27

L1,2 9170-0894 2 CORE-SHIELDING BEAD 28480

T1 9100-5133 1 TRANSFORMER-POWER 28480

J1 1252-4159 1 CONNECTOR-POST TYPE 2.5-PIN-SPCG 11-CONT 28480

TP1-13 0360-2359 13 TERMINAL-TEST POINT .230IN ABOVE 28480

S1 3101-1914 1 SWITCH-SL 2-DPDT STD 1.5A 250VAC PC 28480

S4 3101-3230 1 SWITCH-PB DPST ALTNG 6A 250VAC 28480

S2,3 3101-3273 1 SWITCH-PB MULTISTATION 28480

Agilent PART

NUMBER

1901-0033 14 DIODE-GEN PRP 180V 200MA DO-35 27014 1N645

Q'TY DESCRIPTION MFR.

CODE

MISCELLANEOUS

MFR. P/N

A-14

I

CERTIFICATION

Agilent Technologies certifies that this product met its published specifications at time of shipment from the factory. Agilent
Technologies further certifies that its calibration measurements are traceable to the United States National Institute of Stan­dards and Technology (formerly National Bureau of Standards), to the extent allowed by that organization's calibration facility,
and to the calibration facilities of other International Standards Organization members.

WARRANTY

This Agilent Technologies hardware product is warranted against defects in material and workmanship for a period of three
years from date of delivery. Agilent software and firmware products, which are designated by Agilent for use with a hardware
product and when properly installed on that hardware product, are warranted not to fail to execute their programming instruc­tions due to defects in material and workmanship for a period of 90 days from date of delivery. During the warranty period,
either Agilent or Agilent Technologies will, at its option, either repair or replace products which prove to be defective. Agilent
does not warrant that operation the software, firmware, or hardware shall be uninterrupted or error free.

For warranty service, with the exception of warranty options, this product must be returned to a service facility designated by
Agilent. Return to Englewood Colorado Service Center for repair in United States(1-800-258-5165). Customer shall prepay
shipping charges by (and shall pay all duty and taxes) for products returned to Agilent for warranty service. Except for the
products returned to Customer from another country, Agilent shall pay for return of products to Customer.

Warranty services outside the country of initial purchase are included in Agilent's product price, only if Customer pays Agilent
international prices (defined as destination local currency price, or U.S. or Geneva Export price).

If Agilent is unable, within a reasonable time, to repair or replace any product to condition as warranted, the Customer shall
be entitled to a refund of the purchase price upon return of the product to Agilent.

The warranty period begins on the date of delivery or on the date of installation if installed by Agilent.

LIMITATION OF WARRANTY

The foregoing warranty shall not apply to defects resulting from improper or inadequate maintenance by the Customer, Cus­tomer-supplied software or interfacing, unauthorized modification or misuse, operation outside of the environmental specifica­tions for the product, or improper site preparation and maintenance. TO THE EXTENT ALLOWED BY LOCAL LAW, NO
OTHER WARRANTY IS EXPRESSED OR IMPLIED. AND AGILENT SPECIFICALLY DISCLAIMS THE IMPLIED WARRAN­TIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.

For consumer transactions in Australia and New Zealand:
The warranty terms contained in this statement, except to the extent lawfully permitted, do not exclude, restrict or modify and
are in addition to the mandatory rights applicable to the sale of this product to you.

EXCLUSIVE REMEDIES

TO THE EXTENT ALLOWED BY LOCAL LAW, THE REMEDIES PROVIDED HEREIN ARE THE CUSTOMER'S SOLE AND
EXCLUSIVE REMEDIES. AGILENT SHALL NOT BE LIABLE FOR ANY DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR
CONSEQUENTIAL DAMAGES, WHETHER BASED ON CONTRACT, TORT, OR ANY OTHER LEGAL THEORY.

ASSISTANCE

The above statements apply only to the standard product warranty. Warranty options, extended support contacts, product
maintenance agreements and customer assistance agreements are also available. Contact your nearest Agilent Technolo­gies Sales and Service office for further information on Agilent's full line of Support Programs.

DECLARATION OF CONFORMITY

according to ISO/IEC Guide 22 and EN 45014

Manufacturer’s Name: Agilent Technologies, Inc.

Manufacturer’s Address: 345-15, Kasan-dong, Kumchon-ku,

Seoul 153-023 Korea

declares, that the products

Product Name: DC Power Supply

Model Numbers: E3620A

Product Options: All Options

conforms to the following Product Specifications:

Safety: IEC 1010-1:1990+A1:1992 / EN 61010-1:1993

EMC: CISPR 11:1990 / EN 55011:1991 - Group 1 Class A

EN 50082-1:1992

IEC 801-2 : 1991 - 4KV CD, 8KV AD
IEC 801-3 : 1984 - 3V/m
IEC 801-4 : 1988 - 1kV Power Lines

0.5kV Signal Lines

1)

Supplementary Information: The product herewith comply with the requirements of the
Low Voltage Directive 73/23/EEC and the EMC Directive 89/336/EEC and carry the “CE”
mark accordingly.

1)

The products was tested in a typical configuration with Agilent Technologies Test System.

Seoul, Korea November 1, 1999

Quality Manager

European Contact for regulatory topics only: Hewlett-Packard GmbH, HQ-TRE, Herrenberger Strabe 110-140,

D-71034 Böbligen (FAX: [phone]).