The Transformer

Past and present

1884, year of the first presentation of Goulard and Gibbs secondary generator (see fig.) at the International Electricity Expo in Turin, Italy, largely applauded by the judges.
This year sees the official birth of the first AC transformer and it is also thanks to Goulard and Gibbs for it's actual name. Unfortunately, as true for many inventors, history did not recognize immediate glory and they died very poor, thus let's remember them every time we use a transformer.
After them, other technicians, as Ganz, Stanley, Mordey, the Westingouse Co., Siemens, De Ferranti and Varley studied and designed various transformers, and in few years time developed structures not much different from today's model.
After over 120 years from it's birth, the interest continues in variable transformer developing and manufacturing. What has changed from then to present days?
The basic physics are obviously the same. The major changes concern the material, characteristics and accessories.
From wooden supports to the gum varnish coated cardboard insulation, from soft iron wiring to cut magnetic sheets with very low losses to insulating material which can operate at 200 °C, without loosing their high dielectric characteristics.
From oily varnish coatings for the copper wiring to the present enamels which can operate at 220 °C; from the use of cellulose paper or gutta-percha to the present insulting material in Mylar, Nomex or Kapton.
In the last 50 years, the need for a transformer has increased, from simple use in feeder systems to electronics (where it must work with curve less wave shape).
The three-phase transformer, thanks to it's high quality electric performance, is able to balance always more frequent non-linear electronic and electric systems.
With the enormous use of computers and gaseous discharge lighting systems, the old transformer can help clean the electric lines from harmonics that would otherwise travel freely.
During the past years and with continuous technological improvement, transformers are always more frequently used for everyday devices and have become essential for building regulations.