Hysteresis and eddy current losses are constant at all load levels and dominate overwhelmingly without load, while variable winding amorphous steel for the core and thicker wire, increasing initial cost.
12.
Early transformer developers soon realized that cores constructed from solid iron resulted in prohibitive eddy current losses, and their designs mitigated this effect with cores consisting of bundles of insulated iron wires.
13.
The first Lamme Medal was presented in 1928 to Allan B . Field'For the mathematical and experimental investigation of eddy current losses in large slot wound conductors in electrical machinery '.
14.
To minimize this weight several recent wheel motor designs have minimized the electrical steel content of the motor by utilizing a coreless design with Litz wire coil windings to reduce eddy current losses.
15.
The two losses can be separated by driving the transformer from a variable frequency source since the hysteresis loss varies linearly with supply frequency and the eddy current loss varies with the square.
16.
Other materials were also tried; nonmetallic ferrites were promising for their low electrical conductivity resulting in low eddy current losses, Metglas offered high coupling coefficient, but they were inferior to PZT overall.
17.
During its development between 1836 and the 1860s, mostly by trial and error, researchers discovered many of the principles that governed all transformers, such as the proportionality between turns and output voltage and the use of a " divided " iron core to reduce eddy current losses.
18.
An electrical transformer, for example, has no moving parts, and its mechanical efficiency is generally above the 90 % mark . ( The remaining power losses in a transformer are from other causes, including loss to electrical resistance in the copper windings and hysteresis loss and eddy current loss in the iron core .)
