A power supply of luminous sources is disclosed comprising a first circuit configured to generate a direct voltage signal from an alternating input voltage and a second circuit having in input the direct voltage signal and configured to generate an alternating voltage signal of rectangular wave shape and null average value. The power supply comprises: a third circuit configured to generate a current signal of triangular wave shape from the alternating voltage signal, a fourth circuit configured to extract from the current signal a voltage signal of triangular wave shape and non-null average value, a fifth circuit configured to control the frequency of the alternating voltage signal based on the average value of the voltage signal extracted by the fourth circuit, a sixth circuit configured to rectify said current signal and supply the luminous sources.