DIRECT CURRENT POWER SUPPLY DEVICE

PURPOSE:To improve the use rate of a power supply device, by giving first and second stage setting functions to a dropping current setting circuit and generating electricity stably without increasing the capacity of a DC power supply device even if a device where the input characteristic has a constant power tendency is connected. CONSTITUTION:A dropping current setting circuit 12 is provided with first and second stage dropping current setting functions, and a current value for continuous use rating of a power supply device is set in the first stage, and a current value approximating the maximum allowable in a short time of about 1-2 second is set in the second stage. A switching circuit 13 detects the output of a current detecting circuit 14 and switches the dropping current set to the second stage when the output current of the power supply device is a prescribed value or less and switches the dropping currnet set to the first stage after a delay of about 0.2-2 seconds when the output current of the power supply device becomes higher than the prescribed value. The current detecting circuit 14 is provided for detecting whether a load is connected to the output of the power supply device or not, and a current value or more by which the presence or the absence of the output current of the power supply device is discriminated is set as the prescribed value to the circuit 14.