embodiment of the present invention the direct current power supply device 2 is different from the direct current power supply device 1 of the first embodiment shown in fig1 while the drain terminal of the switching element q 2 is connected to one terminal positive electrode terminal of the smoothing capacitor c 1 in the direct current power supply device 1 the drain terminal of the switching element q 2 is connected to a connection point where the other terminal of the second primary winding n 1 b of the transformer t 1 and the drain terminal of the switching element q 1 are connected together in the direct current power supply device 2 the configuration of the other parts is the same as that of the first embodiment and therefore will not be described in detail according to the present second embodiment unlike the first embodiment the energy accumulated in the smoothing capacitor c 1 is not supplied to the power supply vcc of the control circuit ctl 1 part of the electromagnetic energy released from the reactor l 1 is supplied to the power supply vcc of a control circuit ctl 2 via the second primary winding n 1 b of the transformer t 1 as in.