Unit UTL8500X Series User manual

Programable DC Electronic Load User Manual
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UTL8500X Series
Programable DC Electronic Load
User Manual

Programable DC Electronic Load User Manual
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Preface
Thank you for purchasing this brand new product. In order to use this product safely and
correctly, please read this manual thoroughly, especially the safety notes.
After reading this manual, it is recommended to keep the manual at an easily accessible
place preferably close to the device, for future reference.
Copyright Information
Uni-Trend Technology (China) Co., Ltd. all rights reserved.
UNI-T is the registered trademark of Uni-Trend Technology (China) Co., Ltd.
UNI-T products are protected by patent rights in China and other countries, including
issued and pending patents. Uni-Trend reserves the rights to any product specification
and pricing changes.
Uni-Trend reserves all rights. Information in this manual supersedes all previously
published versions. No part of this manual may be copied, extracted or translated by any
means without the prior permission of Uni-Trend.
Warranty Service
The instrument has a warranty period of one year from the date of purchase. If the
instrument is damaged due to improper operation by the user during the warranty period,
the maintenance fee and the costs caused by the maintenance shall be borne by the user,
and the instrument shall be maintained by the company for life.
If the original purchaser sells or transfers the product to a third party within one year from
the date of purchase of the product, the warranty period of one year shall be from the date
of the original purchase from UNI-T or an authorized UNI-T distributor. Power cords,
accessories and fuses, etc. are not included in this warranty.
If the product is proved to be defective within the warranty period, UNI-T reserves the
rights to either repair the defective product without charging of parts and labor, or
exchange the defected product to a working equivalent product (determined by UNI-T).
Replacement parts, modules and products may be brand new, or perform at the same
specifications as brand new products. All original parts, modules, or products which were
defective become the property of UNI-T.
The “customer” refers to the individual or entity that is declared in the guarantee. In order

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to obtain the warranty service, "customer" must inform the defects within the applicable
warranty period to UNI-T, and perform appropriate arrangements for the warranty service.
The customer shall be responsible for packing and shipping the defective products to the
designated maintenance center of UNI-T, pay the shipping cost, and provide a copy of the
purchase receipt of the original purchaser. If the product is shipped domestically to the
location of the UNI-T service center, UNI-T shall pay the return shipping fee. If the product
is sent to any other location, the customer shall be responsible for all shipping, duties,
taxes, and any other expenses.
Guarantee Limit
This warranty shall not apply to any defects, malfunction or damages caused by
accidental, machine parts’ wear and tear, using outside the product’s specifications,
improper use, and improper or lacking of maintenance. UNI-T under the provisions of this
warranty has no obligation to provide the following services:
a) Any repair damage caused by the installation, repair, or maintenance of the product by
non UNI-T service representatives;
b) Any damage caused by improper use or connection to an incompatible device;
c) Any damage or malfunction caused by the use of a power source not provided by
UNI-T;
d) Any maintenance on altered or integrated products (if such alteration or integration
leads to an increase in time or difficulty of product maintenance).
This warranty is written by UNI-T for this product and it is used to substitute any other
express or implied warranties. UNI-T and its distributors do not offer any implied
warranties for merchantability or applicability purposes. For violation of this guarantee,
UNI-T is responsible for the repair or replacement of defective products as the only and
complete remedy available to customers. Regardless of whether UNI-T and its distributors
are informed that any indirect, special, incidental, or consequential damage may occur,
the UNI-T and its distributors shall not be responsible for any of these damages.
Safety Information
Warning Danger:To avoid electric shock and personal injury, please follow
the following guidelines.

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Disclaimer
Please read the following safety information carefully before using the instrument. UNI-T
will not be liable for the personal injury and property losses caused by the user's failure to
comply with the following terms.
Correct connection of ground wire
To avoid electric shock, please use the provided cable to connect and make sure that the
product is properly grounded before use.
Operating voltage
Please ensure that the main supply does not exceed 10% of rated operating range to
prevent product damage.
Use the correct power cord
Only use the dedicated UNI-T power cord to connect the measured power supply and the
electronic load to ensure that there is no overheat by short-circuit current, otherwise
electric shock may occur.
Input voltage
Please notice the product symbols before connecting. The instrument supports 2 kinds of
AC input method: 110V and 220V. Please check if the switch of load matches with the
input power source and if the fuse is correctly installed.
Please do not use the instrument in inflammable and explosive environment.
Do not use or store the instrument in high temperature, high humidity, flammable,
explosive and strong magnetic field environments.
Do not open the housing of the product.
Non-professional maintenance personnel are not allowed to open the housing to repair
the instrument. The undischarged charge still exists for a period of time after the
instrument is turned off, which may cause electric shock.
Do not use the product if it operates abnormally.
Please contact UNI-T authorized service personnel for inspection. Please disconnect the
power supply and stop using.
Never use the instrument beyond the dedicated range of instruction.
The provided protection will be weaken or invalid. It is forbidden to use this product in
life-support system or other devices with safety requirements.
Only trained personnel can perform the maintenance program.
Any maintenance, adjustment, or replacement of parts must be performed by UNI-T
authorized maintenance personnel.

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Safety symbols
Direct current Alternating current
Direct and alternating
current
Three phase
AC Grounding Protective grounding
Signal
grounding Danger Warning
Neutral wire
or central wire Live wire On (Power)
Off (Power) Backup power
Ground Terminal for
Chassis
Environment-Friendly Use Period (EFUP)
Waste Electrical and Electronic Equipment (WEEE) Instruction 2002/96/EC
This product contains certain hazardous substances and
can be used safely during its environmental-friendly use
period (EFUP) of 40 years, as shown in the symbol on the
left. If the specified time is exceeded, the product should
be recovered.
Do not dispose the product and its accessories in trash bin.

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Table of Contents
Preface.................................................................................................................................2
Copyright Information ..........................................................................................................2
Warranty Service .................................................................................................................2
Guarantee Limit ...................................................................................................................3
Safety Information................................................................................................................3
1. Product Overview ............................................................................................................9
1.1 Product Series ........................................................................................................9
1.1.1 Features .......................................................................................................9
1.2 Front Panel ...........................................................................................................10
1.3 Rear Panel............................................................................................................12
2. Inspection and Installation .............................................................................................13
2.1 Packing List ..........................................................................................................13
2.2 Requirements of Power Supply............................................................................14
2.3 Operating Environment ........................................................................................14
2.4 Cleaning................................................................................................................15
2.5 Handle of Instrument............................................................................................15
3. Measurement Display Interface.....................................................................................16
3.1 Install Load Connection Wire ...............................................................................16
3.2 Power on and Run................................................................................................16
3.3 Introduction of Screen Display .............................................................................17
3.3.1 Display of Measurement Interface .............................................................17
3.3.2 Introduction of Status Bar ..........................................................................17
3.3.3 Running Indicator.......................................................................................18
4. Measurement Settings...................................................................................................18
4.1 Constant State Test Modes ..................................................................................19
4.1.1 Constant Current Test ................................................................................19
4.1.2 Constant Voltage Test ................................................................................20
4.1.3 Constant Resistance Test ..........................................................................21
4.1.4 Constant Power Test ..................................................................................22
4.2 More Modes..........................................................................................................23
4.2.1 Dynamic Mode ...........................................................................................24
4.2.2 List Mode....................................................................................................26
4.2.3 Dual Mode..................................................................................................30
4.2.4 OCP/OPP Mode.........................................................................................32
4.2.5 CR-LED Mode............................................................................................33
4.2.6 Battery Mode..............................................................................................34
4.2.7 Load Effect .................................................................................................36
4.2.8 OVP Mode..................................................................................................37
4.2.9 Short-Circuit Mode .....................................................................................38
4.2.10 Time Mode................................................................................................39
4.3 Parameter Input and Loading Measurement .......................................................41
4.3.1 Numeric Key...............................................................................................41
4.3.2 Pulse Knob.................................................................................................41

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4.3.3 Ripple Measurement..................................................................................41
4.3.4 Input Control...............................................................................................42
4.4 Waveform .............................................................................................................42
4.5 Trigger Method .....................................................................................................43
4.6 Sense....................................................................................................................43
4.7 Screenshot ...........................................................................................................43
4.8 Saving and Applying of Configuration ..................................................................44
5. Fast Charge Test (UTL8511C).......................................................................................44
5.1 QC2.0 Test............................................................................................................44
5.2 QC3.0 Test............................................................................................................47
5.3 QC4.0 Test............................................................................................................49
5.4 PD2.0/3.0 Test ......................................................................................................52
5.5 PE2.0 Test ............................................................................................................54
5.6 DPDN Test............................................................................................................56
5.7 Fast Charge Setting .............................................................................................58
6. System Configuration Page...........................................................................................59
6.1 System Configuration ...........................................................................................59
6.1.1 Language ...................................................................................................60
6.1.2 Key Sound..................................................................................................60
6.1.3 Date............................................................................................................61
6.1.4 Warn Sound ...............................................................................................61
6.1.5 Time............................................................................................................61
6.1.6 DIM Display................................................................................................61
6.1.7 Initial Mode .................................................................................................61
6.1.8 Knob Active ................................................................................................62
6.1.9 Communication Setting..............................................................................62
6.1.10 Restore Factory Setting ...........................................................................62
6.2 Parameter Setting.................................................................................................63
6.2.1 Run Time....................................................................................................64
6.2.2 Delay On ....................................................................................................65
6.2.3 V Trigger.....................................................................................................65
6.2.4 OVP............................................................................................................65
6.2.5 Digit Filt ......................................................................................................65
6.2.6 Ripple .........................................................................................................65
6.2.7 VPP Limit....................................................................................................66
6.2.8 I Rise/Fall ...................................................................................................66
6.2.9 V Rise/Fall..................................................................................................66
6.2.10 Power Type ..............................................................................................66
6.3 File ........................................................................................................................66
6.4 Instrument Info......................................................................................................67
6.5 Local/Remote .......................................................................................................67
7. Communication Interface and Terminal.........................................................................68
7.1 RS-232C...............................................................................................................68
7.2 Current Monitor (I Monitor)...................................................................................69

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7.3 Remote Compensation Terminal..........................................................................69
7.4 Trigger Signal Terminal.........................................................................................70
8. Technical Specifications.................................................................................................71

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1. Product Overview
●Product Series
●Front Panel
●Rear Panel
1.1 Product Series
UTL8500X series DC electronic load contains 3 models: UTL8511S, UTL8512S and
UTL8511C.
Model Measurement range
Voltage Current Power
UTL8511S 0~150V 0~30A 0~150W
UTL8512S 0~150V 0~30A 0~300W
UTL8511C 0~150V 0~15A 0~150W
UTL8500X series DC electronic load comes with 4.3-inch LCD screen, wide power range
and up to 0.1mV/0.1mA resolution. It supports multiple test modes: dynamic test, overload
test, auto test, list test, battery test and CR-LED test, etc. The instrument is a great tool in
areas of electronic performance test, battery set test, power supply test, new energy test,
aerospace industries, high-power test, labs, R&D and production line, etc.
Equipped with standard RS232 communication interface and support more optional
interfaces, UTL8500X series offer multiple solutions for users’ different design and testing
requirements.
UTL8500X series electronic load supports waveform display.
UTL8511C also supports automatic testing of fast charging sources.
1.1.1 Features
Measurement range: 150W/300W,150V,15A/30A
Four basic test modes: CC/CV/CR/CP
Function of remote current monitoring and external triggering
High resolution of 0.1mV/0.1mA
Dynamic voltage/current test with up to 10k dynamic frequency
Voltage/current sampling rate: 40kHz
CR-LED test, power source rise/fall time test
Protections of over-voltage/ under-voltage/ over-current/ over-power/ overheat/ anti-
reverse connection

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The list mode comes with storage function, and supports the saving and applying of
the external U disk and the upgrade of the U disk system.
Screenshot function with list storage & recall
Equipped with standard RS232 interface and support more extension interfaces
(USB or RS-485 converted by RS-232)
Remote voltage compensation input function
Configured with upper computer software for remote control and monitoring
Waveform display
Support automatic testing of fast charging sources (UTL8511C only)
Three dual test modes: CR + CC, CV + CR, CV + CC
OCP/OPP/OVP test and load effect test
Intelligent cooling fan and power-down memory function
Independent short-circuit test function (Only for CC/CV/CR/CP mode)
List auto-power-on function and over-voltage short circuit
Pause function in list mode
1.2 Front Panel
Figure 1-2-1 Front Panel (UTL8512S)
Table 1-2-1 Introduction of Front Panel
No.
Items
Description
①Power button: press it to power on/off
②
USB interface: Users can save the test data and screenshots to
U-disk. It can also be used in list test files storage/recalling and
system upgrade.
③
Numeric keyboard: It is used to enter numbers and decimal
points.
Delete the input values
④
Pulse knob: It is used to adjust the parameters or move cursor in
the menu.

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⑤
Direction keys: They are used to move cursor or adjust the
selected value.
⑥
F1-F6 function keys: They are used to perform the function
displayed on the screen.
⑦
Input terminals: They are used to connect power source. Please
do not inversely connect to prevent damage.
Mode shortcut key: Press to enter setting interface to select CC,
CV, CR, CP and other modes.
System configuration: It is used to set the system parameters,
operating parameters, file operations and view the instrument
information.
In order to avoid misoperation, the instrument adds keyboard lock
function. After pressing the lock key, other keys are disabled
except the ON key. When the key light is on, the keyboard has
been locked; long press for 1-2s to unlock.
Manual trigger button: Press once to operate a manual trigger.
Load input control: ON/OFF
It is used for the test page to return to the initialization interface or
the mode interface to return to the previous level or exit.
This button is used to confirm/modify the selected items or
parameters.
Figure 1-2-2 Terminals on Front Panel (UTL8511C)
NO.
Figure
Description
7-Left
The input terminal+ is used to connect to the on-load
power supply. Please do not reverse connection to
avoid damage to the instrument. Refer to Figure
1-2-3.
7-Right
The input terminal- is used to connect the on-load
power supply, please do not reverse connection to
avoid damage to the instrument. Refer to Figure

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1-2-3.
7-Middle
It is the male end of the quick-charging connector.
These 4 pins are used to connect the 4 terminal holes
of the female end of the quick-charging test board
assembly, as shown in Figure 1-2-3. Note: This jack
socket has a fool-proof design. You need to carefully
align the direction before matching.
Figure 1-2-3 Connection of Terminal and Quick Charge Test Board (UTL8511C)
1.3 Rear Panel
Figure 1-3-1 Rear Panel
Table 1-3-1 Introduction of Rear Panel
No. Items Description
①AC220/110V socket AC power input socket (with fuse)
②ON/OFF power button

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③Trigger signal terminal Please refer to part 7.2 for details.
④AC220/110V transfer switch Voltage scale switch of AC power source
⑤RS232 interface External communication interface to realize
the remote control with the load
⑥Current monitor terminal BNC current monitor output terminal
⑦Sense (remote
compensation) terminal Remote voltage sampling for electrical load
⑧Specification of fuse 250V/0.25A 250V/0.5A
2. Inspection and Installation
●Packing List
●Requirements of Power Supply
●Operating Environment
●Cleaning
●Handle of Instrument
2.1 Packing List
1. Check whether the appearance of the product is damaged, scratched or has other
defects;
2. Check whether the instrument accessories are missing according to the packing list.
If it is damaged or the accessories are missing, please contact Uni-Trend Instrument
Sales Department or the distributor immediately.
Items Quantity UTL8511S
UTL8512S UTL8511C Remarks
Programmable DC
electronic load 1pc √√The model is subject to the actual order.
Power cord 1pc √√
Use only a specified power
cord which is authorized in
the country of use.
Spare fuse 2pcs √√250V/0.5A

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User manual 1pc × ×
Users can download the
manuals from UNI-T’s
official website.
Quick charging
test board 1pc × √
2.2 Requirements of Power Supply
UTL8500X series can only be used in following conditions:
Parameters Requirements
Voltage AC 220/110 (±10%)V
Frequency 50/60Hz
Power 50W
Fuse AC220V input voltage: 250V/0.25A
AC110V input voltage: 250V/0.5A
Three-core power cord is provided. Please make sure that the ground wire of
three-phase socket is properly grounded before use.
The instrument comes with 220V/110V power transfer switch. Before connecting to
the power supply, please check and ensure that the switch is in correct position.
250V/0.25A (5x20mm) fuse is selected and installed for the instrument (220V) with a
spare fuse in the fuse case.
In addition, 2 spare fuses of 250V/0.5A are provided for input voltage of AC 110V.
When replacing the fuse, please remove the external power cord first, then open the
fuse slot under the power interface, take out the old fuse and replace it with a new
one, and install the fuse slot back after completion.
Warning: please do not use the damaged power cord to avoid danger. Use the
250V/0.5A fuse when 110V AC power is input.
2.3 Operating Environment
UTL8500X series can only be used in common-temperature and low-condensing zone.
The general environment requirements are listed as follows. During the on-load process,
the speed of the cooling fan will adjust based on the change of the cooling fin’s
temperature.
Environment Requirements
Operating temperature 0°C~40°C
Operating humidity 20%~80% (Non-condensing)

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Storage temperature -10°C~60°C
Altitude ≤2000m
Degree of pollution II
2.4 Cleaning
To avoid electric shock, please unplug the power cord before cleaning.
Clean the housing and the panel with a soft damp cloth, and make sure it is completely
dry.
Warning: Do not use solvents like alcohol and gasoline.
Do not block the cooling outlet and clean the housing regularly (Unplug the power supply
before cleaning).
2.5 Handle of Instrument
The handle of UTL8500X is adjustable. Please hold the handle by both sides, pull outward,
and rotate it as needed, as shown in figures below.
Figure 2-5-1 Original Handle Position Figure 2-5-2 Handle Position during Measurement
Figure 2-5-3 Removing Position Figure 2-5-4 Lifting Position

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3. Measurement Display Interface
●Power on and Run
●Introduction of Screen Display
3.1 Install Load Connection Wire
The electronic load is connected to the tested object through the "+" and "-" terminals on
the front panel. When making input connections, users need to pay attention to whether
the core diameter of the input wiring is appropriate and whether the positive and negative
polarities correspond. The wire connecting to the load must be thick enough to reduce the
voltage drop on the wire. When measuring large currents, a larger voltage drop will be
generated, so it is recommended to use the Sense terminal of the electronic load for
compensation to ensure measurement accuracy.
Note: Before the connection and test, be sure to check whether the polarity of the
input terminal is connected correctly, otherwise the instrument may be damaged.
3.2 Power on and Run
The correct power-on and self-inspection processes of the electronic load are as
follows:
1. To power the electronic load on, please connect the power cord correctly, adjust the
ON/OFF switch on the rear panel to ON, and press the power button on the front
panel. At this time, the power button is green. The electronic load screen will display
the progress bar of current power-on and self-inspection, instrument information and
other parameters.
2. After initialization, the current measuring status will be displayed on the screen. If the
start-up mode has been set, the instrument will enter the preset measurement mode
directly.
The completion of the correct power-on and self-inspection indicates that the
electronic load meets the factory standards, and users can use it normally.
Turn off the power button on the front panel and adjust the ON/OFF switch on the rear
panel to OFF when the instrument is not in use.
Note: Please read through the safety information in preface carefully before using
the load.

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Warning: Please make sure that the power supply voltage is consistent with the
supply voltage before turning on the power, otherwise the instrument will be burnt out.
Please be sure to connect the main power plug to a power socket with ground protection.
Do not use a wiring board without ground protection.
3.3 Introduction of Screen Display
After entering into the test mode, the LCD screen will be divided into several areas to
display different information.
Figure 3-2 Interface of Measurement
3.3.1 Display of Measurement Interface
No. Items Description
1 Mode Current measurement mode or status
2 Time Current system time
3 System icon
Display the status of U disk, remote compensation,
short-circuit test and trigger function
4 Parameters Real-time voltage, current and power
5 Set value Mode setting information, voltage and current value
6 Other parameters Real-
time running time, other processes and result
data
7 Mode selection (soft
keyboard)
Select the work mode and operate the corresponding
functions at the bottom of the screen
3.3.2 Introduction of Status Bar
Status description Display Status Description
Measurement Status (Mode) Current measurement status or work mode

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status
Control mode Local/Remote Current operating mode: Local/Remote
Screenshot status Waiting/OK/Fail Saving the picture/saved successful/fail
Trigger mode Manual/External Current trigger mode: Manual/External
Remote
compensation Sense Sense
displays on the screen: remote
compensation has been turned on
USB status USB storage device has been connected
System time 0000.00.00
00:00
Current system time: Year/Month/Date /Hour/
Minute
Alarm Audio alarm is on.
Trigger ready Trig
Wait for trigger, the icon will disappear after
triggering
Start-up delay Delay
Wait for start-up delay, the icon will disappear
when reaching the delay time, and then start
up
Short-circuit Short In short-circuit test mode
Pause operation Pause In pause status
3.3.3 Running Indicator
UTL8500X series electronic load comes with running indicator on the ON button. In
on-load mode, the indicator will light up, indicating that the load is in a loaded status.
Pressing the ON button again can stop loading and the indicator will go out.
4. Measurement Settings
●Constant State Test Modes (CC/CV/CR/CP)
●More Modes (Dynamic, List, Dual, OCP/OPP, etc.)
●Parameter Input and Loading Measurement
●Waveform
●Trigger Method
●Sense
●Screenshot
●Saving and Applying of Configuration

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4.1 Constant State Test Modes
There are four types of constant state test modes: constant current (CC), constant voltage
(CV), constant resistance (CR) and constant power (CP). In the initialization interface,
users can select [Mode] by pressing the soft key at the bottom of the screen, and then
press [CC], [CV], [CR], [CP] to enter the corresponding mode.
Users can also press [More] to select other modes, see Table 4-1.
Table 4-1 Introduction of Constant State Test Modes
Name Description
CC mode The electronic load always consumes constant current regardless of the
input voltage.
CV mode
The electronic load changes current consumption to keep the input
voltage as the set value.
CR mode The electronic load is equivalent to a resistor.
It changes the input
current as the voltage changes.
CP mode The electronic load always consumes constant power. It reduces the
current when the voltage rises to remain constant power.
More modes There are many modes under this menu that can be selecte
d by the
cursor to meet diverse testing requirements.
V, A, W
parameters Present voltage, current and power value
Status bar Current mode, time, status and other parameters
In constant state test modes, set current/voltage/resistance/power and other parameters
will be displayed on the right side of screen. Input on-load parameters that need to be set
by numeric keyboard or knob. In on-load status, Time, Vpp, Ipp and other parameters will
be displayed at the bottom of the main screen.
4.1.1 Constant Current Test
In CC mode, the electronic load always consumes constant current regardless of the input
voltage.

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Figure 4-1-1-1 Setting Interface of CC Mode
Operation steps:
1. In initial interface, select [Mode], and then press [CC] to enter the setting interface of
<Constant Current CC>.
2. Move the cursor to current setting by pulse knob, and press the Enter button to
change the current value (the value changes from yellow to white) by keyboard or
pulse knob. Press the Enter button again to confirm. At this time, the set current
value changes from white to yellow.
3. Other parameters can be modified in a similar way.
4. Press the ON button, the electronic load starts to load, and the indicator light below
the button lights up. If users need to stop the load, press the ON button again, and the
running indicator light goes out.
Figure 4-1-1-2 Relationship of Voltage and Current in CC Mode
4.1.2 Constant Voltage Test
In CV mode, the electronic load changes current consumption to keep the input voltage as
set value.
Constant current mode