DC Sources / Loads

Programmable DC power supplies, electronic DC loads, and bidirectional DC systems are essential instruments for the development, validation, and production testing of electronic and energy-related systems. A DC power supply delivers precisely controlled voltage and current to a device under test (DUT), while an electronic DC load absorbs power and simulates a defined electrical consumer. Bidirectional DC systems combine both functions and, depending on the series, can return absorbed energy to the AC mains.

The ET System portfolio includes compact benchtop instruments, multi-channel systems, high-voltage and high-current solutions, and scalable high-power equipment. Available configurations cover applications ranging from individual electronic components and control units to batteries, DC/DC converters, inverters, energy storage systems, and complete industrial test benches.

Select the appropriate product category according to the required energy direction: programmable DC power supplies supply a DUT, electronic DC loads absorb power, and bidirectional DC power supplies support controlled energy flow in both directions. Additional selection criteria include voltage, current, power, dynamics, number of channels, interfaces, mains connection, and mechanical integration.

How to Choose the Right DC Source or Load

The most important selection criterion is the required direction of energy flow between the test system and the device under test (DUT). Once the appropriate product category has been identified, the electrical operating range, dynamic behavior, measurement requirements, automation interfaces, and mechanical integration should be evaluated.

• Supplying a DUT: Choose a programmable DC power supply when the test system only needs to provide controlled voltage and current. Typical applications include powering electronic assemblies, control units, sensors, DC/DC converters, and automated production test systems.
• Loading a DUT: Choose an electronic DC load when the DUT supplies electrical energy and a defined consumer must be simulated. Typical applications include testing power supplies, batteries, fuel cells, converters, and protection functions.
• Energy flow in both directions: Choose a bidirectional DC power supply when the DUT must both receive and return energy. Typical applications include battery simulation, charging and discharging tests, onboard chargers, inverters, and energy storage systems.
• Voltage, current, and power: Define the required values across the complete test sequence. Maximum voltage, maximum current, and maximum power may not always be available simultaneously. Therefore, check the complete operating area rather than only the maximum specifications.
• Dynamic performance: Depending on the application, response time, slew rate, rise and fall times, overshoot, minimum pulse duration, and support for programmable sequences may be relevant.
• Channels and isolation: Multi-channel systems are suitable when several circuits or DUTs must be operated independently. Check the number of channels, available power per channel, channel isolation, and the required isolation between the DC connection and protective earth.
• Accuracy and measurement: Consider programming accuracy, measurement accuracy, resolution, ripple, noise, and data acquisition rate. Precise measurement functions are particularly important for battery, converter, and automated production testing.
• Interfaces and automation: For automated test equipment (ATE), verify remote-control commands, sequence functions, trigger options, software compatibility, and available interfaces such as LAN, CAN, RS232, RS485, USB, SCPI, analog control, or digital I/O.
• Mains connection and energy recovery: Check the available mains voltage, phase configuration, input current, and connection type. Regenerative systems can return absorbed energy to the mains and reduce heat generation compared with conventional dissipative loads.
• Mechanical integration and safety: Consider benchtop or 19-inch rack installation, dimensions, weight, cooling, DC connections, interlocks, emergency shutdown, output discharge behavior, and protection against accidental contact.
• Scalable systems: For higher current or power requirements, check whether the selected series supports parallel or master-slave operation and which operating limits apply to the combined system.

For application-specific test benches, ET System can combine DC power supplies, electronic loads, bidirectional systems, measurement equipment, safety components, and control systems through test system integration. For support with selecting a suitable solution, contact our technical sales team.