DC POWER SUPPLY HAVING VARIABLE OUTPUT VOLTAGE ACCORDING TO LOAD CURRENT VARIATION

摘要

A DC power supply unit is provided to maintain optimum efficiency by reducing variation of a resonant frequency. A DC power supply unit includes an AC/DC conversion part(110), a DC/DC conversion part(120), and a control part(130). The AC/DC conversion part includes a filter, a rectifier, and a power factor corrector. The filter removes electromagnetic interference of a commercial AC power. The rectifier rectifies and smoothes the AC power from the filter. The power factor corrector corrects a rectified power, and outputs a DC power. The DC/DC conversion part converts a voltage level of the DC power. The control part varies a voltage level of the DC power by controlling conversion of the voltage level of the DC power according to a change of a load current of the output power from the DC/DC conversion part.