• This item is only the mainframe

• Modules are sold separately and required for operation
• Multi-channel modular programmable electronic load system
• Mainframe consists of a controller and four open slots
• Seven different load modules are available

The BK Precision MDL4U001 is a mainframe for MDL4U load modules and contains a controller and four open slots. Please note, modules are sold separately and are required for operation.

The MDL4U Series is a multi-channel modular programmable electronic load system. Seven different modules of programmable DC loads ranging in power from 200 W to 600 W provide users the flexibility to test a wide range of power sources from multi-output AC/DC power supplies to batteries, fuel cells, and a photovoltaic array.

The mainframe consists of a controller and four open slots that can be populated with any combination of modules up to 2400 W (up to 4800 W with mainframe extension). The high-performance electronic load modules of the MDL4U Series are capable of operating in constant current (CC), constant voltage (CV), constant resistance (CR), constant power (CW), and constant impedance (CZ) mode, which uses DSP technology to simulate non-linear loads and realistic loading behavior.

Easily edit the load’s parameters such as voltage, current, slew rate, and width via the front panel. Increase productivity by saving your test parameters into any one of the 101 memory areas for quick system recall. Additionally, the MDL4U Series provides 16-bit resolution as well as numerous protection modes and a power-on system self-test to ensure the reliability of your testing.

For remote communication, the MDL4U Series provides LAN, USB (USBTMC-compliant), RS232, and GPIB standard interfaces that support SCPI command protocol.

The mainframe can be populated with any combination of four modules up to a total of 2400 watts (or 4800 with mainframe extension). The MDL4U252 and MDL4U302 are dual-channel load modules.

The MDL4U252 can allocate up to 250 W to either channel up to 300 W total. (e.g. 250 W/50 W, 150 W/150 W).

Similarly, the MDL4U302 can allocate 300 W to either channel up to 600 W total (e.g. 300 W/300 W).

Equipped with a high-performance microprocessor in every mainframe and module, the MDL4U Series programmable DC electronic load utilizes a parallel architecture that provides high measurement speed. Additionally, a simultaneous load on/off operation can be performed through the front panel, analog control terminal, or remote SCPI command. This configuration allows the system to control modules synchronously and increases productivity in testing.

The MDL4U Series mainframe offers all the latest options to the user for remote communication. Connect via GPIB, Ethernet, USB, or RS232 to carry out data communication through SCPI and USBTMC standard communication protocols to control all your electronic load modules from a PC.

With the removable module design, you can choose suitable load modules to modify the system according to your requirements. This design allows for multiple channels and is ideal for testing several units, especially power supplies with multiple outputs. At the same time, all load modules can be configured to work independently. All load modules, including the high power 500 W and 600 W modules can fit in one slot. Unlike competitor models that require two slots for high power modules, the MDL4U Series offers a one-slot form factor for all modules.

In constant current mode, users can control the rate or slope of the change in current in a transient response test. Set the slew rate to as slow as 0.0001 A/μs or as fast as 2.5 A/μs depending on the module and selected current range.

Transient operation enables the module to periodically switch between two load levels. A power supply’s regulation and transient characteristics can be evaluated by monitoring the supply’s output voltage under varying combinations of load levels, duty cycle, and slew rate. The MDL4U Series can simulate these conditions up to 25 kHz.

Not limited to just switching between two levels, list mode lets you generate more complex sequences of input changes with several different levels. Up to 7 groups of list files can be saved in the mainframe. Each list can contain up to 84 steps with a minimum width time of 20 μs per step.

The MDL4U Series can execute multiple test sequences across all channels. Sequences can be cascaded, and each step can be programmed with upper and lower limit values. When applied in automatic production testing, you can easily judge whether the test parameters of your devices are within the specification limits and adjust your process according to the GO/NG verdict.

The MDL4U Series can operate at low voltages for applications such as fuel cell and solar cell testing.