| 摘要 |
PROBLEM TO BE SOLVED: To provide a power supply device that can be surely operated in parallel by suppressing side flow even if the difference of the output voltages of power supply devices is large when a plurality of power supply devices are connected in parallel and are operated without any load. SOLUTION: If the output voltage of a self power supply device is lower than that of another power supply device and a side flow occurs from another power supply device to the self power supply device when the self power supply device which is this power supply device is connected to another power supply device and is operated without any load, the internal voltage of the self power supply device increases, so that an output voltage from a rectification smoothing circuit 2 also increases. A side flow detection circuit 31 outputs a voltage that is reduced according to the increase in the output voltage of the rectification smoothing circuit 2 to a voltage balance circuit 18 and the voltage balance circuit 18 outputs such a signal that the amplitude of a sinusoidal signal outputted from a sinusoidal wave circuit 8 increases to the sinusoidal wave circuit 8, thus causing the output voltage of the self power supply device to increase to the output voltage of another power supply device and hence suppressing the generation of side flow. |
