A notebook computer has a base housing with a heat-generating microprocessor therein, and a lid housing pivotally connected to the base housing. The semiconductor device includes a series-connected circuit of IGBTs between P and N of a DC power supply and an AC switch element that is connected between a series connection point of the series-connected circuit and a neutral point of the DC power supply. The equations define the attribute values and are based on relationships between the attribute and the attributes associated with the same type of object, and different types of objects. The gap distance is about equal to or slightly greater than a thickness dimension of the rectilinear lip element. And, second resonant element is formed of an L-shaped strip.