Tektronix 067-0883-99 User manual

Tektronix,
Inc.
P.O.
Box
500
Beaverton,
Oregon
97077
061-2213-00
Product Group 45
COMMITTED
TO
EXCELLENCE
PLEASE CHECK FOR CHANGE INFORMATION
AT
THE REAR OF THIS MANUAL.
UNIVERSAL
LOAD UNIT
067
-0883-99
INSTRUCTION
MANUAL
Serial Number
_____
_
First Printing AUG 1979
Revised MAR 1982

The
Universal
Load
Unit
is
a
non-supported
Tektronix
product.
* * * * * * * * * *
Although thematerial inthismanual has been
thoroughly
edited and checked
for
accuracy, Tektronix, Inc., makes no
guarantees against typographical or human errors. Also, Tektronixassumes no responsibilityorliability, consequential
or
otherwise, of any kind arising from misinterpretation or misuse of the material in this manual. The contents of this manual
are subject
to
change
without
notice.
Copyright©
1979 by Tektronix, Inc., Beaverton, Oregon. Printed in the United States of America. All rights reserved.
U.S.A. and foreign TEKTRONIX products covered by U.S. and foreign patents and/or patents pending.
TEKTRONIX and TEK are registered trademarks of Tektronix, Inc.

UNIVERSAL LOAD UNIT
LE
F CONTENTS
SECTION 1- GENERAL INFORMATION
Introduction
Description
Electrical Characteristics
Environmental Characteristics
Accessories
SECTION 2 - OPERATION
Front Panel Controls
Rear Panel Controls & Connectors
Initial Turn On
Operational Notes
WARNING I
THE FOLLOWING SERVICING INSTRUCTIONS ARE FOR USE BY
QUALIFIED PERSONNEL ONLY. TO AVOID PERSONAL INJURY, DO
NOT PERFORM ANY SERVICING OTHER THAN THAT CONTAINED IN
OPERATING INSTRUCTIONS UNLESS YOU ARE QUALIFIED TO DO SO.
SECTION 3 - THEORY OF OPERATION
Block Diagram Description
Circuit Description,
High Current Cells
Medium Current Cells
Low Current Cells
Digital Multimeter
Program Board
Power
Supplies
SECTION 4 - CALIBRATION TEST & PROCEDURE
Required Equipment List
Verification Procedure
Calibration Procedure
SECTION 5 - REPLACEABLE PARTS
SECTION 6 - DIAGRAMS & CIRCUIT BOARD ILLUSTRATIONS
APPENDIX A - PROGRAMMING PLUG-IN MODULE
Program Resistor Selection
Safe Operating Area Curves
Replaceable Parts List
Diagrams
i
1-1
1-1
1-1
1-3
1-5
1-5
2-1
2-1
2-4
2-7
2-7
3-1
3-1
3-4
3-4
3-4
3-5
3-5
3-8
3-8
4-1
4-1
4-2
4-4
A-1
A-2
A-10
A-13
A-18

2213-01
Universal Load Unit

UNIVERSAL LOAD UNIT
SECTION 1
GENERAL INFORMATION
Introduction
The Universal Load Unit (ULU) is a bench top testing device that will
provide a convenient method of performance checking the internal power
supplies in several Tektronix instruments. It may be used to test and
verify proper voltage regulation of single and multiple output supplies
under variable load conditions. The ULU is used in conjunction with
Programming plug-in modules that are temporarily installed, one at a time,
into the Load Unit through its front panel.
Description
The Universal Load Unit includes twelve active load cells (channels)
and one passive channel through which up to thirteen output voltage levels
can be concurrently loaded. The current through any active channel is
varied by an internal pulse generator to provide transient response testing.
The voltage or current in a selected channel may be displayed on the Load
Units front panel digital multi-meter. Also, each channel is monitored for
an out-of-tolerance condition.as indicated by one of thirteen comparator-
driven, front panel LED's. The thirteen position CHANNEL SELECTOR switch
is used to connect the ULU controls and output monitoring circuits to each
of the 12 active cells. As selected, each active load cell or channel can
be set up to provide a .resistive load or a constant current load for a
given power supply output. Each active load cell includes a current sensing
resistor, current amplifier and cell protection circuitry. Each programming/load
module supports 12 active and 1 passive channel. All twelve active channels
can be programmed by the installation of six user selected resistors per
channel (See Appendix A). The resistors select high or .low current levels
and equivalent load resistances and establish nominal voltages and tolerance
limits for the ULU's comparator circuitry. The passive channel (13) is
programmed with two fixed resistors.
·Each programming module is used to test the internal power supplies
in a specific Tektronix instrument and will be separately part numbered.
1-1

UNIVERSAL LOAD UNIT
1-2 @

UNIVERSAL
LOAD
UNIT
Electrical
Characteristics
Input
AC
Power
The
ULU
may
be
operated
at
115
or
230
VAC
(48
to
67
HZ)
and
requires
less
than
80
watts
during
normal
operation.
It
uses
a 1
amp
standard
3AG
fuse.
The
power
cord
is
detachable
and
will
plug
into
a female
receptacle
conforming
with
NEMA
#5-15.
(Two-pole,
three
wire
grounding).
Load
Cells
(Channels)
Maximum
and
minimum
input
voltages
and
currents
are
given
in
the
following
tabular
listing.
Current:
Max
Fused
Accuracy
Channels 1,
2,
7'
8 24.A
30A
±5%
± 0.5%
FS
Channels
3,4,9,10
10A
15A
±5%
±
0.
5%
FS
Channels
5,6,11,12
2A
5A
±5%±0.5%FS
Channel
13
1A
Voltage:
Max
Trip
Voltage
Saturation
Amps
(Crowbar)
(minimum)
Channels
1,2
50V
55V
S.2V
@
15A
max.
Channels
7,8
-50V -55V
S.2V
@
15A
max.
Channels
3,4
100V
11
ov
S.4.5V @
10A
max.
Channels
9'
10
-100V -110V S.4.5V @
10A
max.
Channels
5,6
160V 180V
S.8V
@
2A
max.
Channels
11
'12
-160V
180V
S.8V
@
2A
max.
Channels
13
350V
none
S.1V
@
1A
max.
Power
Maximum
•
Channels
1,2,7,8
120W
Channels
3,4,9,
10
80W
Channels
5,6,11,12
80W
Channel
13
10W
*
500
watts
total
input
power,
all
channels.
or
1-3

UNIVERSAL
LOAD
UNIT
1-4

UNIVERSAL
LOAD
UNIT
Operational
Modes:
The
ULU
includes
two
operational
modes;
Chop
individual
and
Chop
All.
Chop
Rate:
Chop
Duty
Cycle:
Chop
Rise/Fall
time:
96
Hz
nominal
50%
nominal
_5-
10
µS
(10%-90%)
Indicators:
The
ULU
includes
two
indicating
devices
-a
digital
multimeter
(DMM)
display
and
10
Out-of-Regulation
LED's.
DMM
Ranges:
DMM
Accuracy:
LED
Accuracy:
Voltage
2v,2ov,2oov,2ooov
±0.1% ± 2
counts
Current
200A,20A,
2A
1%
± 6
counts
±5%
deviation
from programmed
value
Environmental
Characteristics
The
ULU
has
been
tested
and
verified
operable
in
the
following·
class
5
categories:
shake,
shock,
transportation,
bench
handling
and
abbreviated
thermal
tests
(limited
to
o
0
c
to
50°c
with
instrument
on).
Accessories
Standard.
Accessories
for
the
ULU
include
this
manual
(061-2213-00)
and
the
following
listed
items:
Mating
Connectors
P1
&
P2
(2)
Mating
Connector,
P3
AC
Power Cord
Packing
Box
Foam
Pad
Pad
Set
131-0097-00
131-0293-00
161-0066-00
004-0766-00
004-0281-00
004-1092-00
Optional.
Optional
Accessories
for
the
ULU
include
the
following
listed
items:
@
Unprogrammed
Plug-in
&
Connector
Set
7612D
Programming
Plug-in
7612D
Programming
Plug-in
Inst.
Manual
7912AD
Programming
Plug-in
7912AD
Programming
Plug-in
Inst.
Manual
1-5
067-0919-99
067-0921-99
061-2214-00
067-0920-99
061-2213-00

UNIVERSAL LOAD UNIT
SECTION 2
OPERATION
FRONT PANEL CONTROLS
CHANNEL SELECT Control. This 13 position rotary switch connects one
of the 13 channels to other Universal Load Unit front panel controls
including: CURRENT ADJUST, CURRENT LIMIT, CHOP/SWITCH, OVER VOLTAGE TEST,
to indicators including: Digital Multimeter and OUT-OF-REGULATION Lights
and to the External Input Amplifier. The CHANNEL SELECT control also
switches the AC output voltage available at the RIPPLE OUT (+) connector.
OVER VOLTAGE TEST Control. The OVER VOLTAGE TEST control is an end-
of-rotation switch that inserts (or excludes) an internal 75K resistive
divider in series with the remote sense line of the selected channel. CW
rotation increases the magnitude of 'the output voltage of the selected
supply under test. Note that this control will function only if the output
is remote sensed. Caution is indicated in that using this control in any
but the OFF (detented) position may cause damage to the supply under test.
Also, if the supply under test does not have an over-voltage limit, the
ULU's crowbar may be initiated causing an open fuse, damage to the supply
under test or both.
CURRENT ADJUST Control. The CURRENT ADJUST control is a combination
push-pull switch and dual potentimeter. Pulling out on this control engages
the current adjust function; pushing in disengages it. With the control
pulled out, CW rotation increases and CCW rotation decreases the programmed
current level (in positive channels 1 through 6) to the full cell current.
Note that CURRENT ADJUST control rotations are reversed for negative
channels 7-12. In the individual chop mode, the transition level current
is set with the CURRENT ADJUST potentiometer (with the push-pull switch
in).
CURRENT LIMIT Control. The CURRENT LIMIT control is a momentary contact
push button switch. Pushing this switch causes the selected channel to
draw its maximum safe current. The CURRENT LIMIT switch overrides both
programmed current and the setting of the CURRENT ADJUST control. Current
magnitudes are a function of the channel number, its voltage and its
internal protection circuitry.
2-1

UNIVERSAL
LOAD
UNIT
HI/LOW/IND
LOAD
SELECT
Control.
The
HI/LOW/IND
LOAD
SELECT
control
is
a
three
position
toggle
switch
(S2110).
In
its
upper
position
(HI)
all
active
cells
are
set
to
their
high
load
current.
In
its
mid
position
(LOW)
all
active
cells
are
set
to
their
low
load
current.
The
lower
position
(IND)
enables
the
CHOP/SWITCH
control.
CHOP/SWITCH
Control.
The
CHOP/SWITCH
control
is
a two
position
toggle
switch
(S2111).
With
the
HI/LOW/IND
LOAD
SELECT
switch
in
its
IND
position
arid
the
CHOP/SWITCH
control
down,
(SWITCH
position)
the
12
indiviual
MAX/MIN
LOAD
SELECT
switches
(S2001
through
S2012)
are
enabled.
Each
individual
channel
is
then
set
to
its
programmed
high
or
low
current
value
by
the
position
of
its
corresponding
MAX/MIN
switch.
With
the
HI/LOW/IND
LOAD
SELECT
switch
in
its
IND
position
and
the
CHOP/SWITCH
control
up
(CHOP
position)
the
Chop
mode
is
enabled.
Operating
at
a
clock
rate
of
96
hertz,
the
Chop
mode
performs
two
functions,
one
at
a
time,
as
determined
by
the
positions
of
two programming
jumpers
on P2119
(located
on
the
backside
of
the
Load
Select
Toggle
Switches
circuit
board).
These
jumpers
are
accessible
with
ULU's
left
side
cover
off
and Programming/Load
plug-in
module removed.
With
the
P2119
jumpers
connecting
pins
1
to
2 and
4
to
5,
the
INDividual
Chop
mode
is
selected
in
which
only
the
channel
selected
by
the
CHANNEL
SELECT
control
is
chopped
or
step
loaded.
Note
that
the
CURRENT
ADJUST
switch
must be pushed
in
to
enable
the
chopping
action.
Chopper
state
information
is
available
at
the
SYNC
output
BNC
connector.
The
cell
current
value
in
effect
when
the
SYNC
output
is
in
a
TTL
low
state
is
that
set
by
the
MAX/MIN
INDividual
LOAD
SELECT
switch
for
that
channel
(cell)
and
the
corresponding
programming
resistor
value
(in
the
plug-in
module).
The
cell
current
value
during
the
SYNC
output
TTL
high
state
is
that
set
by
the
CURRENT
ADJUST
controls.
The
magnitude
of
this
value
can be
set
by
(temporarily)
pulling
out
the
CURRENT
ADJUST
switch
and
adjusting
it
to
the
desired
value
as
read
on
the
DMM
in
CURRENT
mode. Note
that
the
averaging
nature
of
the
DMM
and
the
50
percent
duty
cycle
of
the
chopper
cause
the
DMM
current
(while
chopping)
to
be
the
average
of
the
two
switched
levels.
With
the
P2119
jumpers
connecting
pins
2
to
3
and 5
to
5,
the
Chop
ALL
mode
is
selected.
In
the
Chop
All
mode
all
active
channels
are
simultaneously
switched
between
their
high
and low programmed
current
values.
Note
that
all
channels
are
high
at
once and
then
all
low
at
once
irregardless
of
the
positions
of
their
respective
MAX/MIN
switches.
2-2

UNIVERSAL
LOAD
UNIT
The
Universal
Load
Unit
includes
two chop modes
to
accomodate
those
instrument
power
supplies
that
cannot
tolerate
all
their
outputs
being
chopped
at
once
without
activating
their
internal
fault
or
protection
circuits.
Damage
may
occur
to
some
power
supplies
when
all
outputs
are
concurrently
chopped.
MAX/MIN
Switch
Array.
The
MAX/MIN
Switch
Array
consists
of
SPST
toggle
switches
(S2001
through
S2012).
These
switches
are
used
to
select
either
high
or
low
load
current
for
each
active
channel.
Both
the
CHOP
ALL
(mode)
and
the
HI/LOW/IND
LOAD
SELECT
switch
will
override
the
individual
MAX/MIN
switches.
VOLTAGE/CURRENT
Control.
The
VOLTAGE/CURRENT
control
is
a
two
position
toggle
switch
located
to
the
right
of
the
Digital
Multimeter.
It
is
used
to
select
the
type
of
measurement
displayed
on
the
Multimeter
(voltage
or
current).
Each
switch
position
is
monitored
by a
corresponding
LED
indicator.
"V"
is
illuminated
for
the
VOLTAGE
switch
position
and
'I'
is
illuminated
for
the
CURRENT
position.
DIGITAL MULTI-HETER.
The
Digital
Multi-Meter
(DMM)
is
an
auto-ranging,
numerical
display
indicator
with
a
four
and a
half
digit
readout.
The
DMM
is
used
to
indicate
the
polarity
and
numerical
value
of
DC
voltage
or
current
on a
selected
channei.
OUT-OF-REGULATION
Indicators.
The
OUT-OF-REGULATION,
indicators
consist
of
13
red
lights
mounted
in
a
group
on
the
upper
front
panel.
There
is
one
light
per
channel
and
when
illuminated,
each
indicates
that
the
particular
supply
voltage
associated
with
that
channel
has
deviated
fom
the
programmed
acceptance
limits.
Selected
resistors
on
the
program
board
are
used
to
establish
the
proper
comparison
voltages
and
the
allowable
tolerance
margins
for
the
supplies
to
be
monitored.
EXTernal
INput
Connector.
EXTernal INput
designates
a
front
panel
BNC
female
connector.
Applying a
voltage
to
the
center
conductor
of
this
connector
causes
the
current
in
the
selected
channel
(1-12)
to
be
increased
or
decreased
in
proportion
to
the
applied
voltage.
A
ten
volt
level
corresponds
to
approximately
100
percent
of
rated
channel
current.
For
cells
1
through
6,
a
positive
voltage
increases
the
absolute
value
of
the
load
current
while
a
negative
voltage
decreases
it.
For
cells
7
through
12, a
negative
voltage
increases
and a
positive
voltage
decreases
the
load
current.
2-3

UNIVERSAL
LOAD
UNIT
RIPPLE
OUT
(+)
&
(-)
Connectors.
RIPPLE
OUT
designates
two
front
panel
BNC
female
connectors.
The
(+)
connector's
center
conductor
is
capacitively
coupled
(via
the
selected
channel)
to
the
power
supply
under
test.
The
(-)
connector's
center
conductor
(shell)
is
connected
to
return
(ground)
of
the
power
supply
under
test.
SYNC
Connector.
SYNC
designates
a
front
panel
BNC
female
connector
that
is
used
to
output
TTL
level
signals.
The
SYNC
output
can
drive
standard
TTL
loads
and
is
used
to
provide
an
oscilloscope
external
trigger
signal
when
the
ULU
is
operated
in
chop mode.
REAR
PANEL
CONTROLS
AND
CONNECTORS
POWER
SWITCH.
The
POWER
SWITCH
is
a
two-position
(ON-OFF)
rocker
switch
used
to
apply
or
remove
AC
power.
230V-115V
SWITCH.
The
230V-115V
switch
is
a
two-position,
flush
mounted
slider
switch
used
to
select
input
AC
voltage.
FUSE/FUSEHOLDER.
The
AC
power
fuse
for
the
ULU
is
a 1 amp/250
volt
standard
fuse.
The
fuseholder
is
located
just
above
the
AC
power
receptacle
and
is
designed
for
3AG
type
fuses.
Pl
NEGATIVE/P2
POSITIVE
CONNECTORS.
P2
POSITIVE
is
the
voltage/current
input
connector
for
positive
channels
(cells)
1
through
6.
P1
NEGATIVE
designates
the
voltage/current
input
connector
for
negative
cells
7
through
12. These
32-pin
male
connectors
mate
with
Tektronix
P/N 131-0097-00
(Amphenol
P/N
26-190-32).
Pin/function
lists
for
P1
and
P2
are
given
in
Tables
1-1 and
1-2.
2-4

UNIVERSAL
LOAD
UNIT
Table
2-1.
P1
NEGATIVE
Pin/Function
List
Pins
Function
1,2,3,4,5
Channel
7,
high
I -
6,7,8,9,10
Channel
8'
high
I -
11'
12
Channel
9,
med
I -
13'
14
Channel
10'
med
I -
15
Channel
11
' low I -
16
Channel 12, low I -
17, 18,
19,20,21
Channel
7,
high
I -
return
22,23,24,25,26
Channel
8,
high
I -
return
27,28
Channel
9,
med
I -
29,30
Channel
10'
med
I -
31
Channel
11
' low I -
32
Channel 12, low I -
return
Table
2-2.
P2
POSITIVE
Pin/Function
List
Pins
Function
1,2,3,4,5
Channel 1'
high
I
+
6,7,8,9,10
Channel
2,
high
I
+
11
'
12
Channel
3,
med
I
+
13'
14
Channel
4'
med
I
+
15
Channel
5,
low I
+
16
Channel
6,
low I
+
17'
18'
19'
20'
21
Channel 1'
high
I
+
return
22,23,24,25,26
Channel
2,
high
I
+
return
27,28
Channel
3,
med
I
+
return
29,30
Channel
4,
med
I
+
return
31
Channel
5,
low I
+
return
32
Channel
6'
low I
+
return
2-5

UNIVERSAL
LOAD
UNIT
P3
SENSE
P3
SENSE
is
the
remote
sense
connector
for
all
cells
and
is
the
power
input
connector
for
cell
13.
This
36-pin
female
connector
mates
with
Tektronix
PIN
131-0293-00,
Amphenol
P/N
57-30360. A
pin/function
list
is
shown
in
Table
2-3~
Table
2-3.
P3
SENSE
Pin/Function
List
Pin
Function
Voltage
remote
sense,
high,
Channel
2
Voltage
remote
sense,
high,
Channel 2
3
Voltage
remote
sense,
high,
Channel 3
4
Voltage
remote
sense,
high,
Channel 4
5
Voltage
remote
sense,
high,
Channel 5
6
Voltage
remote
sense,
high,
Channel 6
7
Voltage
remote
sense,
high,
Channel 7
8
Voltage
remote
sense,
high,
Channel 8
9
Voltage
remote
sense,
high,
Channel 9
10
Voltage
remote
sense,
high,
Channel
10
11
Voltage
remote
sense,
high,
Channel
11
12
Voltage
remote
sense,
high,
Channel
12
13
Channel
13
(Passive
HV)
high
14
Not Used
15
Not Used
16
Fan
interlock
jumper
17
Not Used
18
Not Used
19
1
Voltage
remote
sense,
low, Channel
20
1
Voltage
remote
sense,
low, Channel 2
21
1
Voltage
remote
sense,
low, Channel 3
22
1
Voltage
remote
sense,
low, Channel 4
23
1
Voltage
remote
sense,
low, Channel 5
24
1
Voltage
remote
sense,
low, Channel 6
25
1
Voltage
remote
sense,
low, Channel 7
26
1
Voltage
remote
sense,
low, Channel 8
21*
Voltage
remote
sense,
low, Channel 9
2a*
Voltage
remote
sense,
low, Channel
10
29*
Voltage
remote
sense,
low, Channel
11
30*
Voltage
remote
sense,
low, Channel
12
31
Channel
13
(passive
HV)
return
32
Not Used
33
Not
Used
34
Fan
interlock
jumper
35
Voltage
sense
return
common
to
all
channels
36
Voltage
sense
return
common
to
all
channels
1
Not
currently
used
2-6

UNIVERSAL
LOAD
UNIT
P3
SENSE
also
provides
interlock
capability
for
both
exhaust
fans.
When
electrical
connection
is
made
between
pin
16
and
pin
34
of
P3
SENSE,
the
exhaust
fans
are
controlled
by a
thermal
switch
internal
to
the
ULU
cabinet.
When
these
2
pins
are
not
connected,
both
exhaust
fans
will
run
continuously
whenever
the
ULU
is
turned
on.
NOTE
P3-16
and·P3-34
must
not
be
connected
whenever one
(or
more)
active
load
cell
is
programmed
to
80%
or
more
of
its
maximum
power
rating;
i.e.,
whenever any
high
current
cells
are
programmed
for
96
watts
(80%
X
120W)
or
more,
or
whenever
any medium
or
low
current
cell
is
programmed
for
64
watts
(80%
X
BOW)
or
more. With
the
cooling
fans
running
continuously,
peak
temperature
overstresses
which might
occur
before
the
fans
cycle
on,
will
be
avoided.
Initial
Turn
On
Before
the
power
is
applied
to
the
ULU.
verify
that:
1.
The
120-230
VAC
switch
on
the
rear
panel
is
set
to
match
the
line
voltage
to
be
used.
2.
The
AC
line
fuse
is
the
correct
value
(1
amp.
std.)
is
intact
and
properly
installed.
3.
All
rear
panel
cables
are
securely
connected.
4.
A
Programming
Plug-in
module
configured
to
program
the
ULU
to
test
the
power
supplies
in
a
specific
instrument
has
been
installed.
Operational
Notes
1.
When
testing
Tektronix
7912AD
power
supplies,
do
not
chop
high
current
levels.
2.
CAUTION
-Hazardous
voltages
are
present
when
the
ULU
is
operated
with
its
side
covers
removed.
@ 2-7

UNIVERSAL LOAD UNIT
SECTION 3
THEORY OF OPERATION
Block Diagram Description
A simplified block diagram of the Universal Load Unit is shown in
Fig. 3-1. The diagram illustrates as typical one of the twelve active cells
connected to ULU controls and indicators.
When the output from a power supply under test has been connected to·
the rear panel connectors P1, P2 and P3, continuity can be established
between its output and one or more of the active cells within the ULU via
the CHANNEL SELECT switch. This thirteen position wafer switch connects
ULU controls and output monitoring circuits to each of the twelve active
cells. The thirteenth switch position connects one or two user selected,
fixed resistors between ground and the power supply under test.
The active channels are divided into six groups of two by polarity
and current handling capability as shown in Table 3-1. All cells are ground
referenced.
Table 3-1
Maximum Maximum Maximum
Channel Voltage Current Power
Polarity
1' 2
50 v
24 A 120
W*
+
3,
4 100 v 10 A
80
W*
+
5,
6 150 v 2 A
80
W*
+
7, 8
50 v
24 A 120
W*
-
9,
10 100 v 10 A
Bo
W*
-
11 '
12 150 v 2 A
80
W*
-
13
350 v
10 w +
* or 500 watts total input power, all channels
3-1

S)tNC
Output
EXTen1ci/ @------'
IN put
CURRENT
ADJUST
/VVVV\
G:;:;NT
LIMIT
(pushhuttofl}
S£LFCTED
C€LL
CONTROL
CUR12£NT
!3US~
RIPPLE OUT (t-)@
RIPPLE ourc->@:-----------1
LO~D SELECT
1-11 I
LOW I o 0
INDiv'td1.1al
OllE:RVOL TAG£
rEST
VOLTAG£" .S[IVSE
AUTORIJNG ING
DIGITAL
MULTI-METER
Volto.9e G Cunel'lt
~
OG7-0883-93
CURRENT S€NSE
COMMON SENSE
P/o CHllNN£L
S£LECTOR
SWITCH
3-2
WIN.DO~b
COM PARA TOR1----'-v
CELL
1
PROTECTION
OUT OF R€GULtJ710N
(One LED fer c.ell)
r------1f<EMOTE SENS€ HIGH
OUTPUT HIGH
PLUG-IN
CABLE ASSY
FOWER SUPPLY
UNDER TEST
OUTPUT LOW
12£MOT£ SENSE LOW
Agure 3-1. BLDCk DIAGRAM
UNIVERSAL LOAD UNIT