Dc power supply unit and led lighting apparatus

摘要

In one embodiment, a DC power supply unit includes a DC power supply source (DCS); a load circuit (LC) connected to an output end of the DC power supply source (DCS); a load state detection device (LD) to detect a load voltage or an electric quantity corresponding to the load voltage; and a control device (CC) to receive the detected output of the load state detection device (LD). The control device (CC) controls a maximum output voltage of the DC power supply source (DCS) so that the voltage difference between the maximum output voltage of the DC power supply source (DCS) and the load voltage at the time of normal operation falls within a predetermined range in which are discharge is suppressed.