| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a simple circuit constitution and high reliability for a power supply unit formed by connecting a plurality of power supply units in parallel with each other under constant current operations in drooping characteristic portions. <P>SOLUTION: The plurality of power supply units in which the drooping characteristics perform the constant current operations are connected to an external load in parallel with each other. When only the first power supply unit is started, a drive signal is transmitted to start the next stage unit with the fact that an output current becomes a constant current as a trigger. With the fact that the output current from the next stage unit becomes the constant current as a trigger, a drive signal is transmitted to the third power supply unit, so that the plurality of power supply units are started in a sequentially stepwise manner according to a preset order. The constant current operations in each of the power supply units are controlled by converting the output current from a switching power supply in each of the power supply units into voltage, and comparing the voltage obtained by the conversion with a preset reference voltage. <P>COPYRIGHT: (C)2006,JPO&NCIPI |
