Raytheon has a long history spanning back more than 90 years. The company was founded 1922 under the name American Appliance Company and initially worked on refrigeration technology. They got into the electron tube business with the development of rectifiers, which were an essential part in their 'battery eliminator' which enabled powering radio sets from the AC mains rather than from expensive batteries. They marketed their tubes under the name Raytheon which means 'light from the gods'. In 1925 they changed the name of the firm to Raytheon Manufacturing Company.