ALTERNATING CURRENT GENERATOR

An alternating current generator driven by an engine and capable of obtaining power from an output terminal connected to armature windings according to a plurality of different power supply specifications includes a calculation processing device configured to calculate a remaining capacity from a voltage value between terminals of the output terminal and a current value of a current flowing to the output terminal, and display the remaining capacity. The calculation processing device performs: calculating the remaining capacity as an apparent power value; calculating usage power as an active power value to calculate remaining power by subtracting the usage power from a rated output of the engine; and comparing the remaining capacity with the remaining power, and outputting a smaller value as a remaining capacity display value indicated by the active power value.