| 摘要 |
PROBLEM TO BE SOLVED: To provide a power supply device and a luminaire using the power supply device capable of reducing a standby power.SOLUTION: A voltage corresponding to a current flowing to a switching element Q2 is input to a second drive circuit 20 as a detection voltage Vd. Detecting a termination of reduction of the current flowing on an inductor L2, the second drive circuit 20 turns ON the switching element Q2; and when the detection voltage Vd reaches a predetermined first reference voltage Vr1 or more, the second drive circuit 20 turns OFF the switching element Q2. A control circuit 31 performs a first OFF-operation to maintain the switching element Q2 in an OFF state by maintaining the detection voltage Vd in a state higher than the first reference voltage Vr1; and a second OFF-operation to maintain the switching element Q2 in an OFF state by terminating the supply of the electric power to a part of the second drive circuit 20. When the output is stopped for a long time, the standby power can be reduced by switching from the first OFF-operation to the second OFF-operation. |
