B+K precision 8500 User manual

1
Instruction Manual
Model 8500 300W DC Electronic Load
99 Washington Street
Melrose, MA 02176
Fax [phone]
TestEquipmentDepot.com

2
Warranty Information
Certification
We certify that this product met its published specifications at time of shipment from the factory.
Safety Summary
The following general safety precautions must be observed during all phases of operation 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 .Weassumes no
liability for the customer’s failure to comply with these requirements.
Environmental Conditions
This instrument is intended for indoor use.Pollution degree 2 environments. It is designed to operate at
a maximum relative humidity of 95% and at altitudes of up to 2000 meters. Refer to the specifications
tables for the ac mains voltage requirements and ambient operating temperature range.
Before Applying Power
Verify that all safety precautions are taken. Note the instrument's external markings described under
"Safety Symbols".
Test Equipment Depot - 800.517.8431 - 99 Washington Street Melrose, MA 02176
FAX [phone] - TestEquipmentDepot.com

3
Ground The Instrument
This product is a Safety Class 1 instrument (provided with a protective earth terminal). To
minimize shock hazard, the instrument chassis and cover must be connected to an electrical
ground. The instrument must be connected to the ac power mains through a grounded power
cable, with the ground wire firmly connected to an electrical ground (safety ground) at the
power outlet. Note: 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.
DO NOT OPERATE IN AN EXPLOSIVE ATMOSPHERE
Do not operate the instrument in the presence of fumes or flammable gases.
KEEP AWAY FROM LIVE CIRCUITS
Operating personnel must not remove instrument covers except as instructed in this Guide for
installing or removing electronic load modules. Component replacement and internal
adjustments must be made only 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.
DO NOT SERVICE OR ADJUST ALONE
Do not try to do some internal service or adjustment unless another person capable of
rendering first aid resuscitation is present.
Safety Symbols
Direct current
Alternating current
Both direct and alternating current
Protective earth (ground) terminal
Caution (refer to accompanying documents)

4
___________________________________________________________________
WARNING
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 in personal injury.
Do not proceed beyond a WARNING sign until the indicated conditions are fully
understood and met.
___________________________________________________________________
CAUTION
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 a CAUTION sign until
the indicated conditions are fully understood and met.
___________________________________________________________________
Quick Reference
The Front Panel
1 2
345 6
1
16-character display shows voltage and current measurements.
2
Rotary knob
3
Keypad:
Enable/disable input.
Setup the current, resistance and voltage modes.
Set and reset protection functions.

5
Scroll through front panel.
4
Entry keys:(numeric keys)
Enter values.
Increasing or decreasing the setup values.
Menu commands.
5
Power switch ON/OFF
6
Input terminals.
The Rear Panel
1 2
3 4
1
4Pin Trigger and Remote sensing connectors.
2
9-Pin COM port interface connector.
3
Power switch (110V /220V)
4
3Pin IEC320 ac input connector. (Power code requires ground
conductor).

6
Front Panel Annunciators
OFF power off Trigger Indicates that the electronic load is
waiting an initiate and trigger to
occur.
CC Constant current (CC) mode. Sense Indicates that the electronic load is
in Remote sensing state
CV Constant voltage (CV) mode. Error
Aerrors have occurred
CW Constant power (CW) mode. Link
In the communication state
CR Resistance (CR) mode. Rmt Indicates that the electronic load is
in remote state (RS-232). In the
remote state, only the active key is
the Local key.
Tran The input channel is enabled for
transient operation. Shift
Indicates that the shift key has been
pressed.
List List mode is initiated or running.
Lock keyboard is locked by password
Unreg The input is unregulated.
Immediate Action Keys
V-set
Choosing CV mode and setting the input of regulation voltage mode
I-set
Choosing CImode and setting the input of regulation current mode
P-set
Choosing CPmode and setting the input of regulation power mode
R-set
Choosing CR mode and setting the input of regulation resistor mode
Shift
+
A
Switch to A setting value

7
Shift
+
B
Switch to B setting value
Shift
+
store
Press to store an existing electronic load state in non-volatile Memory.
Shift
+
Recall
Press to recall an existing electronic load state in non-volatile Memory.
Shift
+
Menu
Enter operation Menu.
Shift
+
Short
Turn on or turn off short circuit Test.
Shift
+
Tran
Start /Stop transition operation
Shift
+
Trigger
Causes a trigger to occur.Change the trigger source is IMMIDIATE
Shift
+
Battery
Battery discharge electronic operation
Shift
+
S-Tran
Set the transition operation parameter
Input on/off
Enable or disable load input.

8
Front Panel Menus
1
4
2
8 9
6 05
7
3ESC I-set V-set
R-set
Input on/off
Shift
P-set ENTER
POWER A B Tran
Store Recall S-Tran Menu
Local Battery Short Trigger
Key Pad
0
~
9
0 through 9 are used for entering numeric values.
Decimal point.
ESC The escape key. It may used to exit any working state.
I-set
Choosing CC mode and setup the input current of regulation current mode.
V-set
Choosing CV mode and setup the input voltage of regulation voltage mode.
P-set
Choosing CW mode and setup the input watt of regulation power mode.
R-set
Choosing CR mode and setup the input resistor of regulation resistance
mode.
Shift
Shift keys.
Input on/off
Power ON/OFF
?Scrolling keys let you move through the commands in the presently
Selected function menu. Bring up the next command in the list. Function
menus are circular; you can return to the starting position by continuous
pressing the key.
?Go back to the previous command in the list .Function menus
Are circular; you can return to the starting position by continuous pressing
the key.
ENTER
Confirmation key.

9
Menu Operation
Press Menu to indicate operation mode .View the menu in VFD and using ?and
?to scroll through the completely menu list as following .IFpress
ENTER
key,
you could get the selected menu function. Press ESC back to the previous menu
selection page.
MENU
CONFIG
INITIAL CONFIG Return to the factory default setup value.
POWER-ON RECALL Setting Power-on state of Load.
ON When users turnon the electronic load; the
electronic load setup value will
keep the state of last
time when users turn off the electronic load.
OFF<DEFAULT> Disable this function.
INPUT RECALL Setup of the electronic load input state in Power on.
ON When users turn on the electronic load;the
electronic load input will keep the state of last time
when users turn off the electronic load.
OFF<DEFAULT> When users turn on the electronic load, the
electronic load input will keep the state off.
KEY SOUND SET Keypad sound setting.
ON<DEFAULT> Enable key sound.
OFF Disable key sound.
KNOB LOCK SET Setup Rotary knob lock state.
ON Lock Rotary knob.
OFF<DEFAULT> Unlock Rotary knob.
REMOTE SENSE Setup voltage measurement Mode.
ON The electronic load will measure input voltage
from
the remote sense connector.
OFF<DEFAULT> The electronic load will measure input voltage
from
the front panel connector.
TRIGGER SOURCE Choosing the trigger signals source.
IMMEDIATE<DEF> Trigger signals from
Shift
+
Trigger
key
EXTERNALTrigger signals from the TRIG connector in the
rear panel.
BUS Communication command trigger mode.
BAUDRATE SET Setting baud rate.
9600<DEFAULT>

10
9600
19200
38400
COMM. PARITY SET Command parity setting.
NONE<DEFAULT>
EVEN
ODD
ADDRESS SET Setting communication Flow mode
KEY LOCK SET Setting keypad password.
Press
ENTER
directly to disable the key lock
function.
EXIT
SYSTTEM SET
MAX CURRENT SET Setup the Maximum current.
MAX POWER SET Setup the Maximum Power.
MAX VOLTAGE SET Setup the Maximum Voltage.
EXIT
LIST SET
MODE SET Setting operation mode.
FIXED MODE Fixed mode.
LIST MODE Choosing List mode.
CALL LIST FILE Recall list operation file.
EDIT LIST FILE Edit list operation file.
LIST STORE MODE Us
ers can choose 4 kind of memory space to save the list
file.
8 X 120 STEPS Total 8 filesand each file have120 list steps.
4 X 250 STEPS Total 4 filesand each file have250 list steps.
2 X 500 STEPS Total 2 filesand each file have500 list steps.
1 X 1000 STEPS Total 1 file and each file have1000 list steps.
EXIT
LOAD ON TIMER
TIMER STATE Setting LOAD ON timer state
ON
When users choose the timer state ON, and then
turn on the electronic load input, the LOAD ON
TIMER will start working, and when the LOAD
ON TIMER is reach the setup time,
the electronic
load input will turn off automatically,.
OFF<DEFAULT>
TIMER SET Setting time of LOAD ON timer,
EXIT
EXIT
Test Equipment Depot - 800.517.8431 - 99 Washington Street Melrose, MA 02176
FAX [phone] - TestEquipmentDepot.com

11
General Information
Document Orientation
This manual describes the operation of the Model 8500 DC Electronic Loads. Unless
otherwise noted, all units will be referred to by the description "electronic load"
throughout this User's manual. The following documents and software are shipped
with your electronic load.
This User's Guide (this document), contains installation, checkout, front panel
information and detailed programming information.
The Getting Started Map will help you find the information you need to complete the
specific task that you want to accomplish. Refer to the table of contents or index of
each guide for a complete list of the information contained within.
Getting Started Map
Task Where to find information
Checking out the unit
Verifying proper operation
Using the front panel
Calibrating the unit
User’s Guide
Using the front panel
Front panel keys
Front panel examples
User’s Guide
Using the programming interface
RS-232 interface User’s Guide
Remote operation mode
Protocol information User’s Guide
Controller Program and Software driver:
Power View PV8500 software
Calibration PC8500 software
Active driver PD-8500 OCX software
CD-ROM
Options and Accessories
Options
IT-E151 Rack mounts kit:for install one or two 8500 series load on the 19 inch rack.
ITE-131 isolated communication cable:This cable converts the Electronic Load’s
serial port (TTL 5V level) to PC RS232 interface.

12
Accessories
Power cord
User’s manual
Software CD-Rom
Description
The 8500 serial Electronic Load is used for design, manufacturing, and evaluation of
DC power supplies, batteries, and power components and so on. The Electronic load
contains a processor, serial port connector, front-panel keypad and VFD, and other
circuits common to the other entire load module.
8500 serial Electronic Load could work in constant current (CC) mode, constant
voltage (CV) mode, or constant resistance (CR) mode and constant power (CW)
Mode.
Features And Capabilities
•High accuracy and high resolution
•Capable to work with constant current (CC), constant voltage (CV),constant
resistance (CR) mode and constant power (CW) operation.
•Serial port interface-DB9-RS232 port.
•Triggered input and measurement functions.
•Within the controlled keypad in the front panel
•Built-in pulse generator for continuous, pulsed, and toggled transient mode
operation.
•Over voltage, over current, overpower, and over temperature protection.
•Electronic load calibrate by Software.
•Fan speed control by temperature.
•VFD display
•Short circuit test
•Battery testing function.
Front Panel Controls
The front panel has keyboard controls for setting the input voltage, current and
resistance. The panel display provides digital readouts of a number of functions
including the inputs. Annunciators display the operating status of the electronic load.

13
Remote Programming
The electronic load may be remotely programmed from the computer via the IT-E131
isolated communication cable.
Operating Modes
The four modes of operation are:
1: Constant current (CC).
2: Constant voltage (CV).
3: Constant resistance (CR).
4: Constant power (CW)
Constant Current(CC)Mode
In this mode, the electronic load will sink a current in accordance with the
programmed value regardless of the input voltage. CC mode can be set with front
panel keys. The CC mode parameters are discussed in the following paragraphs.
LOAD
CURRENT
LOAD INPUT
VOLTAGE
I
V
CURRENT
SETTING
CONSTANTCURRENT MODE
Constant Resistance (CR) Mode
In this mode, the module will sink a current linearly proportional to the input voltage in
accordance with the programmed resistance. The CR mode can be set at the front
panel. The CR mode parameters are described in the following paragraph

14
LOAD
CURRENT
LOAD INPUT
VOLTAGE
I
V
SLOPE
RESISTANCE
SETTING
CONSTANT RESISTANCE MODE
Constant Voltage (CV) Mode
In this mode, the electronic load will attempt to sink enough current to control the
source voltage to the programmed value. The module acts as a shunt voltage
regulator when operating in the CV mode. The CV mode can be set at the front panel.
The CV mode parameters are described in the following paragraphs.
LOAD CURRENT
LOAD INPUT
VOLTAGE
I
VVOLT
SETTING
CONSTANT VOLTAGE MODE
Constant Power (CW)Mode
In this mode, the electronic loads will consumption power accordance with the
programmed value regardless of the input voltage.The CW mode can be set with
front panel keys. The CW mode parameters are discussed in the following
paragraphs.

15
LOAD
CURRENT
LOAD INPUT
VOLTAGE
I
VPOWER
SETTING
CONSTANT POWER MODE
V2
V3
I2 I3
Transient Operation
Transient operation enables the electronic load to periodically switch between two
load levels, as might be required for testing power supplies. A power supply's
regulation and transient characteristics can be evaluated by monitoring the supply's
output voltage under varying combinations of load levels, frequency, and duty cycle.
Transient operation can be turned on and off at the front panel or PC via the IT-E131
isolated communication cable.Before you turn on transient operation, you should set
the desired mode of operation as well as all of the parameters associated with
transient operation. Transient operation may be used in the CC, CR, or CV or CW
modes and can be setup in continuous, pulsed, or toggled operation mode.
Continuous
Generates a repetitive pulse stream the toggles between two load levelsand change
the state between value A and value B.
10A
5A
Continuous Transient Operation
2.0ms 3.0ms

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Pulse
Switch to value B as receiving one trigger signal , taking the pulse time(TWD)of value
B , Load will return to Value A .
10A
5A
Pulsed Transient Operation
10ms
TWD 10ms
TWD
TRIG TRIG
Trigger Mode
Switching the state between value A and value B once receiving atriggering signal
10A
5A
TRG TRG
Toggled Transient Operation
List Operation
List mode lets you generate complex sequences of input changes with rapid, precise
timing, which may be synchronized with internal or external signals. List operation can
be changed by edit every step value and time in list operation. The parameter of list
operation include the group file name, input step setting (the max steps is 1000
steps),time of one step(1mS~1h)and setting value of one step. In CC mode, dwell
time range is 1mS to 6S, which also have an associated value. Note that lists data can
only be saved in total 1000 steps memory of 4 situations.
GROUP Total = 1000 steps

17
11000 steps
2500 steps 500 steps
4250 steps 250 steps 250steps 250steps
8120
steps
120
steps
120
steps
120
steps
120
steps
120
steps
120
steps
120
steps
When receiving one trigger signal, it will start the list operation until receiving another trigger
signal or finish the List operation.
Trigger
10 2 3 4 5
List count=1 List count=2
List sequence
Triggered Operation
The electronic load has various triggering modes to allow synchronization with other
test equipment or events. Such as:
Keypad triggering mode:Press
Shift
+
Trigger
to trigger the electronic load.
TTL triggering mode:Send ahigh pulse with a constant time more than 5m Sec to
the trigger terminals in rear panel to trigger the electronic load.
Command triggering mode: Send triggering command to the electronic load via the
serial port.

18
Input Control
Short On/Off
Load can simulate a short circuit at its input by turning the load on with full-scale
current. The short circuit can be toggled on/off at the front panel using the
Shift
+
Short
.Short operation is not influence the operation setting current
value , When short operation is on OFF state , Load back to the original setting state.
The actual value of the electronic short is dependent on the mode and current range
that are active when the short is turned on.
In CC, CW and CR mode, the max short-circuit current value is 1.2 times of the
current range. In CV mode, short-circuit operation is same as the operation of setting
CV to 0V.
NOTE
Turning the S Sh ho or rt t T Te es st ton in CV mode may cause the load to draw so much
current that the software current limit operates, which may turn the input off.
Turning the short circuit on does not affect the programmed settings, and the
load input will return to the previously programmed values when the short is
turned off.
Input On/Off
Electronic load's input can be toggled on/off at the front panel. Turning the input off
(zero current) does not affect the programmed settings. The input will return to the
previously programmed values when the input is turned on again.
NOTE
The Input On/Off command supersedes the mode commands and Short Test
On/Off command.
Operation Range
Work in the range of Rated Current, Rated voltage and Rated Power, The
figure is as following:

19
INPUT VOLTAGE V
Rated voltage Rated power
Input current I Rated current
Operation mode change state
INPUT VOLTAGE V
Rated voltage Software Power Limit
Input current I Rated current
Software Current Limit
C
A
Protection Features
Electronic load includes the following protection features:
Over Voltage
If input voltage exceeds the voltage limit, Load will turn OFF the input, Buzzer is
mooing. VFD display as following:
OVER VOLTAGE

20
Over Current
When work in the CR or CC and CP mode, input current is ascending continuously,
the load current will be limited by a current limit circuit, Load will work in the over
current protection state , VFD display the information as CC.
When work in CV mode and transition mode and List mode, Input current exceeds the
current limit, Buzzer is mooing, VFD display the flashing current value.
OverPower
If the input power exceeds the power limit in the normal operation mode, Load will
work in the over power protection state. VFD displays the information as CW.
When work in transition mode and list mode,If the input power exceeds the power
limit. Buzzer is mooing, VFD display the flashing current value and voltage value.
Reverse Voltage
This feature protects the load module in case the input DC voltage lines are
connected with wrong polarity, if a reverse voltage condition is detected, Buzzer is
mooing. VFD display as following:
Over Temperature
If internal power components ‘s temperature exceeds safe limits (80?), Over
temperature protection is on work . Load will turn off the input and Buzzer is mooing,
VFD display as following:
Remote Sense Function
When work in CV, CR and CP mode, if load consumes biggish current, it will cause
one depressed voltage in the connection line between tested machine and terminals
of Load. In order to assure testing precision, Load provides one remote testing
terminals in the rear panel, Users could test the output terminals voltage of tested
machine through it. Users should set the Load in REMOTE mode before using the
function.
REVERSE VOLTAGE
OVER HEAT
Test Equipment Depot - 800.517.8431 - 99 Washington Street Melrose, MA 02176
FAX [phone] - TestEquipmentDepot.com