Another scheme of the rotary type, perhaps even better adapted to the
distant control of large motors, is a small synchronous radio motor
driven by power carried by radio from the broadcasting station to the
receiving stations. It is, of course, rotated partly by radio power from
the distant station, and partly by local current, just as a loudspeaker
is operated. These small motors, rotating in synchronism with the motor
at the sending station, control the rotation of a larger motor in each
receiving camera, and so all stations keep in step.