Abstract: The patent application refers to a conversion circuit with high efficiency for power supplies which in addition has the capability of changing alternating current to direct current and vice versa, adjusting the voltage supplied automatically for the load. These circuits can include schemes for isolating the inputs from the outputs of the circuits by switching capacitances, with less losses than conventional schemes and marked by their high efficiency with relation to the parasitic capacity at the input and the output. The entire circuit is controlled digitally, whether supplying a constant current or a constant voltage.