# power adjustment

While in voltage matching the voltage at the load resistor (Ra) is highest when the internal resistance (Ri) of the voltage source goes to zero (Ri "Ra), in current matching it is the other way round: the internal resistance of the current source goes to infinity and the load resistance to zero (Ri "Ra). And power matching is optimal when both resistance values, that of the internal resistance and that of the load resistance are equal (Ri=Ra). In this case, the voltage across the load resistor is half of the open circuit voltage.