Power Supply Device and Luminaire

摘要

According to one embodiment, there is provided a power supply device includes a DC-DC converter and a protection circuit. The DC-DC converter includes a switching element of a normally on type, a current control element of the normally on type connected to the switching element in series and configured to control an electric current flowing to the switching element, and a rectifying element connected to the current control element in series. The DC-DC converter converts, according to ON and OFF of the switching element, an input first direct-current voltage into a second-direct current voltage, which has an absolute value different from an absolute value of the first direct-current voltage, and supplies the second direct-current voltage to a load. When an electric current equal to or larger than a predetermined value flows to the switching element and the current control element, the protection circuit cuts off the electric current.

主权项

1. A power supply device comprising:
a DC-DC converter including:
a switching element of a normally on type;a current control element of the normally on type connected to the switching element in series and configured to control an electric current flowing to the switching element; anda rectifying element connected to the current control element in series. the DC-DC converter converting, according to ON and OFF of the switching element, an input first direct-current voltage into a second-direct current voltage, which has an absolute value different from an absolute value of the first direct-current voltage, and supplying the second direct-current voltage to a load; and a protection circuit configured to cut off, when an electric current equal to or larger than a predetermined value flows to the switching element and the current control element, the electric current flowing to the switching element and the current control element.