An amplidyne is an electrodynamic amplifier invented during World War II by Ernst Alexanderson. It is an early form of servomechanism used to implement position feedback control for large motors. A small electrical signal can control the position of a large motor using this approach.
In its simplest form, an amplidyne follow up system consists of
How it works"The synchro control transformer receives the order signal which indicates electrically what the position of the load should be. The rotor of the synchro control transformer is turned by the response shaft, which is geared to the load and so indicates what the position of the load actually is. The synchro compares the actual load position with the ordered position; and, if the two do not agree, it generates an alternating-current signal which is transmitted to the amplifier. The angular difference between the two positions is called the error, and the signal to the amplifier is the error signal. The error signal indicates by its electrical characteristics the size and direction of the error. If no error exists, the system is said to be in correspondence and the error signal is zero."
ApplicationsAmplidynes were initially used to point naval guns, and later, land artillery.
Later used to control processes in steelworks.
Used to remotely operate the control rods in early nuclear submarine designs (S3G Triton).