Electronic loads and load banks are used to test electrical and electronic equipment. They mimic load requirements for testing and troubleshooting purposes.

Types of Electronic Loads and Load Banks

There are four basic types of electronic loads: benchtop, slot, modular, and system.

• Benchtop loads are relatively inexpensive, but limited in terms of range and accuracy.
• Slot loads measure a single set of variables and are similar to benchtop models.
• Modular loads have a computer chassis and are designed for applications with changing load configurations. Although modular loads with more than one chassis are available, devices with a single chassis can be configured to act as a single load in dynamic modes.
• System loads are designed for near-continuous duty and include an integral transient generator. They are more expensive than other types of electronic loads and load banks, but provide a wider range of features.  

Specifications

Electronic loads and load banks differ in terms of product specifications. Input specifications include power, voltage, current, and frequency. Modular loads also vary in terms of number of loads per chassis. As a rule, smaller electrical loads require fewer card slots. Measurement type and efficiency are other important considerations when selecting electronic loads and load banks. There are seven main measurement types:

• voltage
• current
• peak-current
• frequency
• crest-factor
• power-factor
• true power

Efficiency, a measure of power, is usually expressed as a percentage for electronic loads and load banks.  

Features

Emulation mode and product features are important considerations when selecting electronic loads and load banks. Most products provide up to five emulation modes: constant-current, constant-voltage, constant-resistance, constant-power, and short circuit. Alternating current (AC) and direct current (DC) outputs are usually characterized as high, low, or medium power. In terms of features, electronic loads and load banks may include a graphical user interface (GUI) and integral software. Test results can be sent to a digital front panel, a printer, or a personal computer (PC).   

Applications

Electronic loads and load banks can be used for design verification, multiple unit production testing, and troubleshooting inbound devices for repairs. Some products are used to test AC power supplies, DC power supplies, switching power supplies, or uninterruptible power supplies (UPS). Others are designed to test fuel cells, inverters, telecommunications rectifiers, batteries and battery charges. Programmable electronic loads and load banks are used with automatic testing equipment (ATE) and a variety of units under test (UUT).

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