NOVELTY - The device (100) has a first printed wiring board assembly (600) arranged on a heat-dissipating base (200). The first printed wiring board assembly comprises a first printed wiring board (610). A first electronic component is arranged on the first printed wiring board such that the first printed wiring board assembly comprises a raised portion (600P) and a concave portion (600R) relative to the raised portion. A second printed wiring board assembly (910) is partially arranged in the concave portion.    USE - Electronic device i.e. on-board charge module (OBCM), for a car battery charger (claimed) for charging battery packs of an electric vehicle i.e. car.    ADVANTAGE - The heat-dissipating base is designed according to a configuration of the heat-dissipating base, the first printed wiring board assembly, the second printed wiring board assembly, and the first electromagnetic induction module, so as to enhance overall heat-dissipating efficiency of the electronic device by properly designing a structure of the heat-dissipating base to make the heat-dissipating base with a first protrusion and a second protrusion, in which the first protrusion top surface of the first protrusion and the second protrusion side surface of the second protrusion thermally contact the first component and the second component of the electronic device. The device prevents heat generated by the first electromagnetic module from directly transferring to the heat-dissipating component since the heat-dissipating component is separated from the three-dimensional structure, thus avoiding affecting heat-dissipating efficiency of the heat-dissipating component for the switching element.    DETAILED DESCRIPTION - An INDEPENDENT CLAIM is also included for a car battery charger.    DESCRIPTION OF DRAWING(S) - The drawing shows an exploded perspective view of an electronic device.    Electronic device (100)    Heat-dissipating base (200)    Printed wiring board assemblies (600, 910)    Raised portion (600P)    Concave portion (600R)    Printed wiring board (610)