Abstract: A substrate connecting structure includes a substrate that includes a flat base material having a first surface and a second surface at a side opposite to the first surface, a first wiring layer arranged on the first surface, and a second wiring layer arranged on the second surface, a through hole extending through the base material, a connection metal body that includes a connecting portion connected to the second wiring layer and a projection inserted into the through hole, and a mounted component mounted on the substrate. The connection metal body is connected to the mounted component only at a distal end surface of the projection.

Abstract: A substrate connecting structure includes a substrate that includes a flat base material having a first surface and a second surface at a side opposite to the first surface, a first wiring layer arranged on the first surface, and a second wiring layer arranged on the second surface, a through hole extending through the base material, a connection metal body that includes a connecting portion connected to the second wiring layer and a projection inserted into the through hole, and a mounted component mounted on the substrate. The connection metal body is connected to the mounted component only at a distal end surface of the projection.

Abstract: An isolated DC-DC converter includes a transformer, a main switch, an active clamp circuit and a control unit. The transformer has a primary winding. The main switch and the active clamp circuit are connected to the primary winding. The active clamp circuit has an auxiliary switch and a clamp capacitor connected in series. The control unit is provided for controlling the main switch and the auxiliary switch. The control unit performs a soft start operation of the converter before a normal operation. The control unit performs anti-saturation control before starting the soft start operation. The anti-saturation control includes an act of controlling the main switch and the auxiliary switch so that the auxiliary switch performs ON-OFF operation with the main switch kept OFF until voltage of the clamp capacitor drops below a level at which the transformer is to be magnetically saturated after starting the soft start operation.

Abstract: An isolated DC-DC converter includes a transformer, a main switch, an active clamp circuit and a control unit. The transformer has a primary winding. The main switch and the active clamp circuit are connected to the primary winding. The active clamp circuit has an auxiliary switch and a clamp capacitor connected in series. The control unit is provided for controlling the main switch and the auxiliary switch. The control unit performs a soft start operation of the converter before a normal operation. The control unit performs anti-saturation control before starting the soft start operation. The anti-saturation control includes an act of controlling the main switch and the auxiliary switch so that the auxiliary switch performs ON-OFF operation with the main switch kept OFF until voltage of the clamp capacitor drops below a level at which the transformer is to be magnetically saturated after starting the soft start operation.