Abstract: An electrical composite rotating machine capable of developing output shaft speeds in excess of the synchronous speed of a single motor without resort to gearing or frequency changers. An a-c electric motor is equipped with a rotor which is at one end connected to a rotatable field structure of a second motor. When the first two-pole motor operates at a nominal shaft speed of 3600 rpm, it also drives the field structure of the second motor at 3600 rpm. When the field of the second two-pole motor is activated, the rotor of the second motor rotates at a speed of 3600 rpm relative to its field structure, thus developing an output speed of 7200 rpm. With different numbers of poles in the respective motors, different shaft output speeds can be achieved.