August 29, 1831: Michael Faraday invents the transformer

British physicist and chemist Michael Faraday (1791-1867) is seen, date unknown. (AP Photo)

by: David Tristan

Posted: Aug 29, 2023 / 09:33 AM EDT

Updated: Aug 29, 2023 / 09:31 AM EDT

LONDON, (WHTM) — One of the greatest scientific minds in history was largely self-educated.

Michael Faraday (1791-1867) was born to a poor family, and received only a few years of formal school education before becoming an apprentice at age 14. To the immense good fortune of himself, and ultimately the entire world, he apprenticed to a bookseller. Faraday spent much of his seven year apprenticeship reading as many books as he could. Along the way he developed an interest in science-especially the bizarre, complex, confounding, amazing and barely established science of electricity.

Soon after his appenticeship ended he was appointed an assistant at the Royal Institution of Great Britain, a major center for science education and research. His experiments would refine the theories underpinning electricity; in fact he was the first to realize that, contrary to the beliefs of the time, there was only one kind of electricity, which produced different phenomena depending on the amount of power introduced to the system.

Along the way he invented some cool stuff.

In 1821 he performed an experiment in which electrical energy was converted into motion-the first electric motor. Then on August 29, 1831 he tested an iron ring, which had been wrapped with two loops of insulated wire. The two wrappings were not connected in any way, shape, or form, and yet, when he connected a battery to one wire coil, the other wire would produce a measureable electric current. Faraday had demonstrated the principle of mutual induction-the electricity in one coil of wire stimulated the production of a magnetic field in the iron, and the magnetic field then stimulated an electrical signal from the other coil. He had also created the first transformer-and without the transformer, our modern electrical infrastructure couldn’t exist.

You see, the two coils of wire in a transformer do not need to have the same number of turns around the core. If the current is connected to the coil with fewer turns (the Primary in this picture) the coil with more turns (the secondary) will put out more voltage than went into the primary. This is what’s called a step-up transformer. .

In a step-down transformer the process is reversed. The electricity feeds into a primary coil with more turns than the secondary coil, which results in less voltage coming out of the secondary.

We benefit a lot from step-down transformers. High voltage lines from power plants are rated at up to 750,000 volts, and sometimes more. (This is because (a) a lot of power gets lost as heat going through transmission lines, and (b) heavy industry has heavy power demands.) The transformer at a substation will reduce the voltage, and the transformer on your utility pole (usually a grey cylinder) will reduce the voltage even further, so it can feed into your home without setting your wiring on fire. Finally the power cords for your computer, cell phones, tablets, chargers, etc. contain small transformers to step down the voltage even more.

And we can trace this innovation back to Michael Faraday and his early experiments in electricity.