On our strength poles and in our strength supplies, in our communication equipment and in our cars, transformers help spread strength, isolate signals, and create voltage to spark our ignition. Transformers, sending electrical energy from one wire of wire to another, transform varying electrical current into changing magnetism, and then back to electrical current.
Like most inventions though, transformers didn’t suddenly appear on the scene. Over many years a series of discoveries and inventions, when connected together, evolved into the transformers we have today.
Some 2800 years ago, one of the first discoveries was made independently by the Greeks and the Chinese. They noticed that lodestones would attract. Because of this allurement, the Greeks named them magnets.
Advancements toward transformers, beyond the lodestone, didn’t occur until the late 1500’s with William Gilbert, a mathematician. He was one of the first to use scientific methods to probe the occurrence of magnetism. In 1600, likening the polarity of a magnet to the polarity of the earth, he published his findings on magnetism.
Between 1785 and 1791, Charles Coulomb who was also a mathematician published papers showing the inverse square laws of repulsion, both for electrical force and magnetic force.
Magnetism and Electricity
Hans Christian Oersted, in 1820, discovered that passing an electrical current by a wire of wire produced magnetism. That discovery, that electricity causes magnetism, was an important step in the invention of the transformer.
In 1831, more of the ideas required for the transformer were understood. The discovery of electro-magnetic induction was made independently by Michael Faraday and Joseph Henry. They had found out that a changing a magnetic field, inside a wire of wire, induced an electrical current in the wire.
Then in 1836, while giving a demonstration to a class he was teaching, Nicholas Joseph Callan (professor of Natural Philosophy, now called Physics) placed two coils of wire next to each other. Having first connected a battery to one of the coils, he disconnected the battery; a spark jumped between the wires on the second wire. Using magnetism, electrical strength had been induced in a second wire of wire using electrical current in the first. This was a transformer. strength had been transferred from one wire of wire to another using an electrically induced magnetic field.
Between the 1830s and the 1870s, experiments, mostly using trial and error, revealed the basic principles of transformers.
By 1876 the Russian engineer Pavel Yablochkov was using coils, essentially transformers, for an arc lighting system. By 1885, Ottó Bláthy, Miksa Déri and Károly Zipernowsky, from the Ganz factory in Budapest, started manufacturing transformers to spread strength for electric lighting. They had over fifty strength systems installed in Austria-Hungary.
Transformers, since their original use for strength dispensing, are also employed in many other applications. They’re used in audio, video, RF, and instrumentation. They increase or decline voltage; they increase or decline current. Transformers can be as small as a few millimeters across or as large as a school bus.
Today the basic principles of the transformer, with all the variations, are nevertheless the same. A transformer changes electrical energy from a varying current in one wire of wire into a fluctuating magnetic field. This magnetic field then passes its energy to another wire in the form of varying electrical current.