A new approach for tracking the maximum power point of photovoltaic arrays is presented. The maximum power point tracker output voltage and current are used for control purposes, rather than for its input voltage and current. It is shown that using the output parameters simplifies the maximum power point tracker controller. Moreover, using this approach, only one out of the two output parameters needs to be sensed. This observation is general and applies regardless of the power stage or the realisation control algorithm. Contrary to what might have previously been assumed, it is theoretically shown that the MPPT control that uses a single output control parameter applies to nearly all practical load types, regardless of the load nature.