An electronic load may be used, for example, for factory and in-service testing of standby generators. A load bank may be used to stabilize a power system in case of loss of load, for example, on an isolated wind or mini-hydro plant.
An electronic load (or e-load) is a device or assembly that simulates loading on an electronic circuit. It is used as substitute for a conventional ohmic load resistor.
As counterpart to a current source, the electronic load is a current sink. When loading a current source with a fixed resistor one can set one determined load current by the connected load resistor. The characteristic of the electronic load is that the load current can be set and varied in a defined range. The load current is regulated electronically.
The electronic load consumes electric energy and in most cases transforms it into heat. Fans or water-cooled elements are used as coolers. Under certain conditions, energy-recycling into the public power supply system is also possible.
Electronic loads are used in diverse applications, particularly for the test of power supplies, batteries, solar and fuel cells, generators. AC loads are used to test transformers, uninterruptible power supplies (UPS) or onboard power supplies. The equipment and power spectrum of such electronic loads begins with simplest circuits consisting in general of a potentiometer for current setting and a transistor circuit for power transforming. Further developed electronic loads supply several operating modes, in most cases constant current, voltage, power and resistance. Nowadays, the equipment may be controlled by a PLC or remotely by a PC. Settings and measured values such as input voltage and actual load current are indicated on a display.