Measuring the latter allows a constant power load mode (as power = current * voltage). In his article, [Kerry] shows that he can simulate a load of up to 200W.

Voltage close voltageThe potential difference across a cell, electrical supply or electrical component. It is measured in volts (V). is a measure of the difference in electrical energy between two ...

The r.m.s. value of an a.c. signal is equal to the value of direct current (d.c.) which would have the same effect or energy change as the a.c. The r.m.s. voltage of an a.c. signal is always less ...