Abstract: A power storage system includes a storage unit, a charging circuit configured to supply a charging current to the storage unit, and a controller connected to the storage unit. The storage unit includes plural capacitor elements connected in series to one another each having both ends, plural resistors connected to the capacitor elements, and plural switch elements connected to the capacitor elements and the resistors. One of both ends of each capacitor element of the plural capacitor elements is connected to one end of a corresponding resistor of the plural resistors. Another of the both ends of the each capacitor element is connected to one end of a corresponding switch element of the plural switch elements. Another end of the corresponding resistor is connected to another end of the corresponding switch element.

Abstract: In a semiconductor integrated circuit device, a plurality of a field effect transistors are formed on a (110) crystal surface of a group III-V compound semiconductor substrate having a zinc blend type crystal structure.

Abstract: An IC device comprising a plurality of FET's using a compound semiconductor, more specifically, a zincblende type semiconductor substrate, having a surface of a (111) plane. By use of this plane, differences of characteristics of the FET's depending on directions along which gates of the FET's are arranged when the gate length is made shorter are prevented, allowing arrangement of gates of the FET's in different directions, particularly perpendicular to each other, with making the gate length shorter to miniaturize and densify the device.