Boost converter

The converter has inputs to which direct current (DC) power sources (10a-10c) is connectable, and a common output (24) at which DC voltage is provided, where a value of the DC voltage is larger than that of input voltages. The output is connected with the inputs over a positive line and a negative line. Inductors (12a-12d) and rectifier elements (16a-16d) i.e. diodes, are arranged in the positive and negative lines from the inputs. The inputs are switchable in series by switching elements (14a-14d) over the inductors. Two of the inductors are parallely switchable. The switching elements are MOSFETs or insulated gate bipolar transistors (IGBTs). The DC power sources are solar generators, fuel cells, thermoelectric generators, accumulators, batteries, super capacitors, electromagnetic generators, alternating current (AC)/DC converters, DC/DC converters. An independent claim is also included for an inverter circuit comprising a boost converter.