To provide a power supply device which can evenly supply electric power outputted from a plurality of generators to electric loads, by generating reference voltages corresponding to each current detecting voltage, and controlling each AC-DC converting means so that the differences between the output voltage of each AC-DC converting means and the reference voltages may become smaller.

A balance circuit 120 is connected to the positive-electrode terminal of an operational amplifier element 113 through voltage dividing resistors 111 and 112. To the negative-electrode terminal of the element 113, a DC voltage converted by means of a smoothing capacitor 47 is supplied. The output terminal of the element 113 is connected to the gates of thyristors 41, 43, and 45. Therefore, the operational amplifier element 11 outputs control signals which control the gates of the thyristors 41, 43, and 45 to the gates of the thyristors 41, 43, and 45, by comparing the values of the reference voltages generated from the balance circuit 120 through the resistors 111 and 112 with the value of the DC voltage converted by means of the capacitor 47.