An object of the present invention is to provide an aliphatic polyester which is produced as a high-molecular-weight one without using a chain extender such as an isocyanate compound or a carbonate compound and is excellent in moldability in injection molding, blow molding, or extrusion molding, thermal stability, and mechanical properties such as tensile properties. An active matrix display device of the invention comprises a first current input terminal, a second current input terminal, and a plurality of current supply lines extending parallel to each other. A crank sensor signal is analyzed as the engine coasts to a stop so an engine reversal can be detected. Terminals of the inner inductor, for example, are not tapped from the outer inductor, which can reduce parasitic effects and electromagnetic interference relative to tapped inductor designs.