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What is skin effect in wires & cables? + Meltdown & Spectre: sometimes good guys win - Printable Version

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What is skin effect in wires & cables? + Meltdown & Spectre: sometimes good guys win - C C - Jan 9, 2018

What is Skin Effect in Wires and Cables?
http://www.studyelectrical.com/2018/01/what-is-skin-effect-in-wires-and-cables.html

EXCERPT: When dealing with low current dc hobby projects, wires and cables are straight forward they act as simple conductors with essentially zero resistance. However, when you replace dc currents with very high-frequency ac currents, weird things begin to take place within wires. As you will see, these “weird things” will not allow you to treat wires as perfect conductors. Skin effect is one among them. We are discussing about this phenomenon in this article....

MORE: http://www.studyelectrical.com/2018/01/what-is-skin-effect-in-wires-and-cables.html



Meltdown and Spectre: Sometimes the Good Guys Win
http://engineeringethicsblog.blogspot.com/2018/01/meltdown-and-spectre-sometimes-good.html

EXCERPT: Most computer viruses and bugs go for particular operating systems, Windows being the most popular, because it's on the majority of PCs. So Mac users, although occasionally suffering their own kinds of attacks, usually breathe a sigh of relief every time a major PC-only virus hits the news.

But over the weekend, you may have heard about a pair of bugs called Meltdown and Spectre that go for hardware, not software. In particular, Meltdown is a vulnerability associated with Intel processors made since 1995, and the dominance of Intel means Macs, PCs, and most you-name-it computers are potential targets. Spectre reportedly is even worse. But the key word here is "potentially." In an announcement, Apple claimed that no known malicious hacks have actually been committed using either of these bugs. And by the time the general public learned about them, the major computer and software makers were already well on their way to devising fixes, although the fixes may have their own drawbacks.

The reason no bad guys have apparently used these bugs is that they were discovered independently by computer researchers in Austria and the United States. And following a policy called "responsible disclosure," the researchers notified Intel that their chips were vulnerable to these bugs. So until now, apparently the criminal elements of the computer world either didn't know of the bugs or didn't use them.

I am not a computer scientist, but the technical details of how Meltdown happens are interesting enough to try to summarize....

MORE: http://engineeringethicsblog.blogspot.com/2018/01/meltdown-and-spectre-sometimes-good.html


RE: What is skin effect in wires & cables? + Meltdown & Spectre: sometimes good guys win - elte - Jan 10, 2018

I had wound some air core output filter coils for an early version of switching power supply that I made. They would get scorchingly hot, and I was guessing skin effect was the trouble.