Power supply with reduced switching losses by decreasing the switching frequency

摘要

A power source device includes an input terminal, a first switching element connected to the input terminal, a second switching element connected to the first switching element, a transformer having a primary coil connected to a connecting node between the first and second switching elements, a low-pass filter including a series body of a coil and a capacitor connected to a secondary coil of the transformer, an output terminal connected to a connecting node between the coil and the capacitor, a comparator having a first input terminal connected to the output terminal, and an alternating signal generator connected to a second terminal of the comparator. An output terminal of the comparator is connected to each control terminal of the first switching element and the second switching element via the temporary amplitude generation permissible section.