This Bachelor’s thesis describes a design and testing of an increasing direct voltage converter transforming light energy received by a photodiode to electrical energy with sufficient output voltage to power digital circuits. The theoretical part forms an overview of commercial circuits and the Linear Technology LTC3109 and the combination of Seiko S-822Z20 and S-8353D30MC are chosen as suitable for the further research. The function principles of these circuits are described. In the practical part the maximum output power and efficiency dependences on the internal resistance of the power source of the circuits are measured. Based on the results the characteristics of the Linear Technology circuit with different variants of the input transf...