MetaFilter posts tagged with electronics and engineering

Revolutionary Semiconductor

daniel_charms — Fri, 27 Mar 2009 13:35:51 -0800

Friday Flash Fun*: Конструктор: Engineer of the People, in which you are an engineer working in a top-secret semiconductor facility called H3, designing top-secret integrated circuits based on specifications provided to you. *For certain values of 'fun'

Deep Geek: Understanding Memristors

NortonDC — Sun, 07 Dec 2008 19:54:57 -0800

The coming memristor revolution in electronics and how it works. The newly created memristor, only the fourth fundamental fundamental type of passive circuit element, has the promise of computing advances both prosaic (faster, cheaper and "bigger" flash drives) and momentous (relatively effortless mimicry of brain cells and their activity). This is the story of the memristor's genesis, told by R. Stanley Williams, the leader of the team that created the device. Being deeply geeky myself, I've read about memristors before, but reading this article and sidebar finally let me understand how the memristor works and what happens inside it. And that felt pretty damn good. The article is fantastic, but it does leave one key connection unmade. To create a practical memristor, the team "needed [a] mechanism by which we could change the effective spacing between two wires in our crossbar by 0.3 nm. If we could do that, we would have the 1000:1 [variation in conductivity] we needed... Where would we find a material that could change its physical dimensions like that?" They did create a way to vary that spacing, in a controllable, repeatable, and extremely fast-acting manner, but Williams doesn't directly explain how the internal actions of the switching layer meet that requirement. The payoff for that setup is missing. When electrical current pushes the conductive impurities in the layer of titanium dioxide toward the other wire, the conductive portion of the layer grows toward the other wire, and the insulating portion of the layer thins. That thinning is described, but the article never tells the reader that expansion of the conductive layer is that long-sought means of moving the wires. If you read the article and made that connection before I described it, then you might have felt as smug about it as I did. Williams gets to feel more smug.

The Man Who Invented Stereo

rongorongo — Thu, 07 Aug 2008 09:10:27 -0800

In a single 1931 document, electrical engineer Alan Blumlein patented stereo records, stereo movie sountracks and surround sound. His equipment was used to make some of the first stereo recordings at EMI's Abbey Road studios - several decades before the technology came into popular use. Blumlein went on to pioneer 405 line TV (the first wholly electronic format which won out over John Logie Baird's rival system) and to produce the equipment that made the first outside TV broadcast possible. At the outbreak of World War 2 he was a key architect of the secret H2S radar project. Unfortunately he was killed in a plane crash while testing the technology and the whole incident was kept secret. Hence he remains an obscure figure despite his achievements. A recent BBC Radio 4 program contains a lot of the archive stereo footage and tells his story.

Freely-available textbooks

Upton O'Good — Thu, 25 Oct 2007 23:35:44 -0800

Open Text Book: a blog which lists freely-available online textbooks. These textbooks include ones for basic and advanced math (warning: giant PDF), engineering, electronics, and philosophy, among others.

Anita: the world's first electronic desktop calculator

riffola — Mon, 21 Apr 2003 23:10:33 -0800

Anita Mk VII the "A New Inspiration To Accounting" OR "A New Inspiration To Arithmetic" was the world's first electronic desktop calculator. Launched in 1961, the Mk VII and Mk VIII were the only commercial calculators available for a period of two years.

lagado — Sun, 28 Jan 2001 19:50:45 -0800

There's been a lot of talk of late about signal-to-noise ratios here on MeFi (er, Ashcroft who?...). Generally, we think of noise as something that always degrades the quality of a signal. Sometimes, however, the opposite can be the case. Here's a neat little demonstration of a non-linear system in which noise can be used to amplify a signal that would otherwise be too be faint to detect any other way. It exploits a phenomenon known as Stochastic Resonance.