Notes from Ian McNeil's Encyclopedia..

From "An Encyclopedia of the History of Technology" by Ian McNeil

"The advantages of alternating current transmission encouraged
engineers to develop AC motors. Most DC motors will in fact operate on
AC supplies, provided that the iron cores in their fields are laminated, but
they are not so efficient. Such machines are called universal motors, and
are often found in small domestic appliances such as vacuum cleaners and
food mixers." pag.383

"Food mixers and refrigerators came after the First World
War, though they were rare until the 1950s." pag.386

"The breakthrough, as with all other labour-saving devices in the home,
came with the introduction of the small electric motor. This only became
available for the domestic market in suitable form and at reasonable cost soon
after the First World War when such motors were adapted into the design of
kitchen equipment such as blenders, mixers, beaters and choppers. Although
sophisticated electrical equipment of this type was in use in America by the
1920s, electric food mixers, for example, did not come into common use in
Britain until after 1945." pag.937