The concern on observed climate change has increased the utilization of renewable energy sources. The harvesting of solar energy is recognized as one of the key issues in reducing green house gas emission. Reliable solar-energy systems composing of solar arrays and their interfacing converters are of prime importance in uninterrupted solar energy production. The interfacing maximum-power-point converters are implemented usually by modifying the conventional voltage-fed converters. Actually, the modifications change the converter into a current-fed converter with corresponding steady-state and dynamic properties. The paper investigates the true properties of these transformed converters based on theory and practical measurements. As an example a direct-duty-ratio-controlled voltage-fed buck converter is shown to be transformed into a current-fed boost-type converter.