Power MOSFET is core of regulated-dc electronic load

摘要

Designers use electronic dc loads for testing power supplies and sources, such as solar arrays or batteries, but commercial ones are often expensive. By using a power MOSFET in its linear region, you can build your own (Figure 1). It uses two simple feedback loops to allow the transistors to work as a current drain in current-regulation mode or as a voltage source in voltage-regulation mode. Designers use current-regulation mode when they are characterizing voltage sources, in which the power source must deliver current value that is set in the electronic load. They use voltage-regulation mode with current sources because it forces the sources to operate at a voltage that the load sets.