DC Electronic Loads
DC electronic loads are programmable test instruments, emulating the DC resistance load normally required when undertaking functional tests of power supplies, solar cells and batteries. The main components of an electronic load are power transistors, power IGBTs mounted on heat sinks, cooling fans and an electronic circuit that controls the current that devices on test can draw from the power supply. These devices offer a presettable power limit, to limit the power to the power curve of the devices being tested and thereby protect it from damage. Electronic loads are used by power supply manufacturers and others as alternatives to fixed-resistor banks, to subject their products to dynamic testing. Electronic loads facilitate easy and quick simulation of various power states. Electronic loads also deliver a much higher throughput compared to fixed resistors, for varying loads. An electronic load may also be used as a high-speed current modulator, to enhance the performance of a power supply. Modulating the current to the highest level ensures low voltage across the load, and when current is modulated off, voltage rises. This ensures the power supply works at only a fraction of its power rating. Electronic loads are available in different interfaces, displays and voltage capabilities. USB interfaces are the most common nowadays.