PURPOSE: To provide a switching type charger which has low power loss, a simple structure of a high frequency transformer and in which a cost increase is suppressed.

CONSTITUTION: A DC/DC converter 20 has a switching element 21, a high frequency transformer 22 and a rectifying diode 26. A rectified output voltage V10 of a main power source circuit 10 is supplied to a series circuit of a primary coil 22p of the transformer 22 and the element 21, and a charge voltage V20 is output from the diode 26. Another rectifier diode 44 is provided in a sub-power source circuit 40. The diode 44 is connected to a feedback coil 22f of the transformer 22. A DC voltage V44 to be output from the diode 44 is supplied to a charge controller 30.