The test environment at high capacity is influenced by the inductance of the load cable, and depending on how it is used, it can lead to damage to the electronic load device. To be able to deal with such external factors, the high-speed current control circuit method used in the Load Station series has been further improved and adopted in the QL-D series. The faster load response ensures stable operation against instantaneous overcurrents at high currents and prevents abnormal oscillation caused by cable inductance when the cable wiring is extended, allowing for safer use.
General large-capacity DC electronic load (conventional circuit method)
Inrush current occurs
QL-D series (high-speed current control circuit type)
Ideal current response with no inrush
General large-capacity DC electronic load (conventional circuit method
Overshoot current occurs
Achieves smooth current response
Front panel designed for ease of use
Compact body with ample large capacity. Three models (150V, 600V, 1000V) with different rated voltages ranging from a minimum of 5kW to a maximum of 25kW are available. The 150V type supports a maximum current of 2000A. Recommended for those who want large capacity at low cost.
*QL-D-5K-1/B is a benchtop type. All others are caster types. *The master-slave connection cable option requires one cable equal to the number of connections.
*QL-D-5K-6/B is a benchtop type. All others are caster types.
*QL-D-5K-1K/B is a benchtop type. All others are caster types.
Despite its large capacity, it achieves a current measurement accuracy of 0.2%. Compared to the master-slave method, the setting error and measurement error of various load modes are small, and setting accuracy and measurement accuracy are guaranteed.
It has 12 load modes (CC, CR, CV, CP, Short, CC+CV, CP+CV, EX (CC, CV, CP), EXT (CC+CV, CP+CV) and 6 operation modes (Normal, Dynamic, Sequence, Sweep, MPPT (optional), current limit), which can be combined to perform a wide variety of load tests.
Dedicated operation modes "CC+CV mode" and "CP+CV mode" are included as standard, making them ideal for evaluating battery characteristics. They are also suitable for evaluating the discharge characteristics of large-capacity batteries.
The Vlimit function and elapsed time measurement function are used to turn off the load at a specified voltage or discharge time, enabling battery protection.
It is equipped with a function that turns off the load when the specified integrated value is reached using the integration function (current: AH and power: WH).
It is equipped with an independent current limit function that is different from the load mode control. When the set current is detected, it can limit the current to 110% of the limit setting value (current) without turning off the load, while the load is on. The operation when the limit is detected (load off or 110% limit load while the load is on) can be set individually. It can be used as a protection function at any limit value.
In addition, by using a current limit in constant voltage mode, the CV+Clim function allows operation at 110% of the current limit setting at the set CV voltage, making it possible to use the unit in constant voltage/constant current mode for battery discharge, etc.
High-speed current control technology has enabled a high-speed response of up to 50A/μs (150V type).With a minimum response time of 5μs, the device achieves a fast rise time despite its large capacity and current.
Setting current at maximum slew rate
Click to enlarge
Difference in current response at a slew rate of 10A/μs at the minimum response time
When using current rise (QL-D-5K-1) with a maximum slew rate of 50A/μs
In addition to the standard two-step (HIGH/LOW, two-value) dynamic mode, 32-step dynamic operation is possible. This allows for testing with more detailed current waveforms. The current waveform can be set graphically using the color LCD, and operation settings can be made in either time or period (frequency display). The pulse width can be set from 1 μs, and frequencies up to 500 kHz* can be set.
Condition: Dynamic mode step count
32 repeatable patterns
Current waveform in Dynamic mode
Condition: Dynamic mode pulse width
The built-in memory for sequence operation is 4,096 words, allowing sequence programs to be created by data transfer or directly from the front panel. Data can be transferred via various communication interfaces, as well as read and saved from USB memory (CSV file format). The execution time and slew rate settings for each step are common, with the execution time ranging from 1 msec to 10 min. The slew rate setting is only available in CC mode and sets the speed of current change (A/μs) when transitioning from step to step.
Sweep mode is a function that measures voltage and current while finely changing (sweeping) the load current in three load modes (CC, CR, CP), and plots the measurement results on the LCD panel in real time to create a chart (graph).
The electronic load can perform overcurrent characteristic tests (drooping characteristics) and overpower characteristic tests on SW power supplies, as well as IV characteristic tests on secondary batteries, etc. The measurement data can be saved in CSV format to a USB memory. As it has a judgment function, it can be used in OCP and OPP test modes in addition to characteristic evaluation.
An optional MPPT function (hill climbing method) is available, which is necessary for testing solar cell panels (PV), etc. This control method continuously adjusts the load current using CC mode while measuring the load voltage until maximum power is obtained.
Up to eight conditions such as load mode and load setting value can be saved/read.
LAN/USB/RS-232C are provided as standard. A GP-IB converter (RS-232C conversion) is also available as an option.
By connecting a USB memory stick to the dedicated USB port, measurement data such as Sweep mode can be saved to the USB memory stick. Settings for SEQUENCE mode and Dynamic mode can also be read and saved from the USB memory stick.
For PLC control, it is equipped with external digital control (EXT I/O) and external analog control (EXT INPUT). It supports load mode switching and analog control load setting (CC, CV, CP) with 0-10Vdc. It also has current and voltage monitors (isolated) and can read measured values, and CC+CV and CP+CV modes can also be controlled from a PLC.
EXT I/O (external digital control)
EXT INPUT (external analog control)
MONITOR (isolated output)
Master-slave connection is possible with a single parallel operation cable. Up to six units (including the master unit) can be connected in parallel as long as they are of the same voltage, even if they have different capacity models, allowing for flexible capacity expansion up to a maximum of 150kW.
Remote sensing allows you to change the voltage reference point for voltage measurement and CR, CV, and CP modes from the load input terminal to any sensing point. By setting the sensing point to the end of the device under test, you can eliminate the effects of voltage drops due to the resistance of the load cable and stabilize the load mode that serves as the voltage reference.
"*" indicates the load capacity of each model
The standard model is a caster type, but the 5kW model also comes in a benchtop type in addition to the caster type.It uses rubber feet similar to those found on general benchtop power supplies, allowing you to create a test environment on a table.
In addition, it can be easily mounted in a rack by simply removing the rubber feet, and the benchtop type is ideal for system setup using a 19-inch rack.
Equipped with an emergency stop switch, which is essential in the car electronics industry. It is large and easily visible from the front panel, and has a guard to prevent malfunction. In addition to operation from the front panel, it can also be controlled from an external digital control (EXT I/O).
All models come standard with a safety cover for the load input section, which handles high voltages and large currents. This load input terminal section is designed for maximum usability and safety.
Anchor bolt fixing brackets are available as an option to prevent the enclosure from falling over.