I always Don’t like exaggerated claims about upcoming scientific and technological breakthroughs, such as cheap fusion, cheap supersonic flight, and the formation of other planets. But I like simple devices, they can complete many basic tasks of modern civilization, especially those that are humble or even invisible.
No device fits this description better than a transformer. Non-engineers may be vaguely aware of the existence of such devices, but they do not know how they work and how indispensable they are in daily life. (A transformer is a device that transfers current between two circuits while changing the voltage (that is, the “pressure” of the current power).)
The theory is based on the discovery of electromagnetic induction by Michael Faraday and Joseph Henry in the early 1830s. They showed that a changing magnetic field can induce a higher voltage (called “boost”) or a lower voltage (“buck”) current. But it took another half a century for Lucien Gaulard, John Dixon Gibbs, Charles Brush and Sebastian Ziani de Ferranti to design the first useful transformer prototype. Next, the Hungarian engineers Ottó Bláthy, Miksa Déri and Károly Zipernowsky improved the design by manufacturing a toroidal (doughnut-shaped) transformer, and exhibited the transformer in 1885.
In the second year, three American engineers worked for George Westinghouse and introduced better designs—William Stanley, Albert Schmid and Oliver B. Shallenberger (Oliver B. Shallenberger). The device soon adopted the form of the classic Stanley transformer, which has been retained since then: a central iron core made of thin silicon steel sheets, one part of which is shaped like an “E”, and the other part is shaped like an “I”. To make it easy to use. Slide the wound copper coil into place.
When Stanley addressed the American Institute of Electrical Engineers in 1912, he marveled at how the device provided “such a complete and simple solution” to the problem. Therefore, this casts a shadow over all mechanical adjustment attempts. In this easy, deterministic and economical way, it handles the large amount of energy immediately provided to or derived from it. It is so reliable, powerful and certain. In this object made of a mixture of steel and copper, the extraordinary power has reached a good balance that is almost beyond doubt. “
This durable design is the largest modern body, making it possible to transport electricity across distances. In 2018, Siemens delivered the first batch of seven record-breaking 1,100 kV transformers, which will provide electricity to several provinces in China connected to a nearly 3,300 km long high-voltage DC line.
Due to the explosive growth of portable electronic devices that must be charged, the number of transformers has exceeded Stanley’s imagination. In 2016, the global production of smartphones alone exceeded 1.8 billion, and each smartphone was supported by a charger equipped with a micro-transformer. You can see the heart of small devices without disassembling the mobile phone charger. The complete iPhone charger disassembly has been posted on the Internet, and the transformer is one of its largest components.
But many chargers even contain smaller transformers. These are non-Stanley (non-wire-wound) devices that utilize the piezoelectric effect (the ability of a strained crystal to generate current and the ability of current to strain or deform the crystal). The sound waves hitting this crystal will produce electric current, and the electric current flowing through this crystal will produce sound. In this way, one current can be used to generate another current with a very different voltage.
The latest innovation is the electronic transformer. Compared with traditional devices, their volume and mass are greatly reduced, and they will become particularly important for integrating intermittent power sources (wind and solar) into the grid and enabling DC microgrids. Without transformers, we will not have the era of ubiquitous electricity, but will fall into the era of oil lamps and telegraphs.
From Numbers don’t lie Written by Vaclav Smil and published by Penguin Books, the book is the brand of Penguin Publishing Group (a subsidiary of Penguin Random Bookstore LLC). Vaclav Smil Copyright © 2020.
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