ARRAY 3731A Programmable DC Electronic Load 240V/60A 800W

11/30/2025

ARRAY 3731A Programmable DC Electronic Load 240 V/60 A 800 W:

• Supports input voltage range up to 240 V and current up to 60 A, with a maximum power dissipation of 800 W.
• Supports multiple load modes: Constant Current (CC), Constant Voltage (CV), Constant Resistance (CR), and Constant Power (CP).
• High-speed sequence / high-speed transient capabilities, allowing dynamic load changes.
• Interfaces: USB Device + RS-232 (allowing PC control / automation) and supports SCPI commands.
• Accuracy specs (for example in CC mode): 0-6 A low range resolution ~0.1 mA, high range up to 60 A with 1 mA resolution; Voltage range 0-240 V.
• High power capacity: With 800 W capability, the 3731A can handle fairly heavy DC sources, making it suitable for bench-testing of medium to high power supply units, batteries, or solar panels.
• Flexible load modes: The four primary modes (CC, CV, CR, CP) let you emulate different types of loading conditions (constant current draw, constant resistance load, constant power draw, etc.), which is important for thorough validation.
• Automation-friendly: With USB/RS-232 and SCPI support, the instrument is ready for automated test setups or integration into a test bench. That helps in repeatable high-volume or regression testing.
• Dynamic capability: The high-speed transient/sequence features allow you to simulate rapidly changing loads (for example pulsed discharge, battery load cycles, etc.), which many simpler loads cannot keep up with.
• Professional tool: It’s positioned for serious lab or production use rather than just hobby.

If you are developing a custom DC-DC converter that takes an input of up to 200 V and supplies load currents up to 50 A. You need to validate how your converter behaves under varying load conditions (steady current, step changes, resistance-like load, and varying input voltage) to ensure stability, thermal behavior, and ripple/noise.

How the 3731A comes into play:

1. Connect the output of your DC-DC converter (say 200 V nominal) to the 3731A’s input terminals, ensuring the voltage is within the 0-240 V range.
2. Use the load in Constant Current (CC) mode: set it to draw 50 A steady. This simulates the max load condition. Verify converter stays within spec, thermal stable, ripple acceptable.
3. Use Constant Resistance (CR) mode: set a resistance value (e.g., 4 Ω at 200 V ≈ 50 A) and sweep the input voltage from 200 V → 180 V → 220 V to see how output current shifts, how converter regulation holds.
4. Use a high-speed transient/sequence: program the 3731A to alternate between 10 A for 0.5 s, 50 A for 1 s, 30 A for 0.5 s in a loop. This simulates a pulsed load scenario (e.g., a motor startup or surge load) allowing you to see how the converter responds, how output voltage dips/spikes, how ripple behaves, how the thermal profile evolves.
5. Use Constant Power (CP) mode: set a power draw of e.g. 600 W, and vary the input voltage or converter output voltage, to see how your system handles fixed power draw despite load or input shifts.
6. Use the USB/RS-232 interface + SCPI commands to automate a long test routine: e.g., log current/voltage/power over time, automatically change load steps, trigger alarms if parameters deviate, then export logged data for analysis.

Benefits:

• You get a single instrument that covers many test scenarios (CC/CV/CR/CP) so you don’t need multiple load units.
• You test your converter under realistic dynamic load conditions, not just static steady-state. That uncovers issues such as transient overshoot/undershoot, regulation instability, thermal stress.
• You can automate the process, saving manual effort and improving repeatability (especially useful in production or regression testing).
• Because the load handles up to 60 A and up to 240 V, you’re covered for the converter’s full operating envelope.