Calculator Accuracy & Usefulness

[Garth Wilson]

(05-26-2015 04:24 PM)Claudio L. Wrote:  In electronics, almost any PCB board with a fast clock needs to be ran through a finite element program to determine electro-magnetic interference between adjacent tracks.
It's not something perceptible to humans, like your audio examples, but a CPU running at GHz speeds can't tolerate that a bit gets randomly flipped on a track. In the past, this didn't matter because speeds were slower and components and tracks were much larger.
As things get faster and smaller, we need more numerical digits with more advanced methods to properly design, fabricate and even operate our engineering creations, and this is a lot of the engineering being done today.

You're talking my language. In the 1980's, I worked in applications engineering at a company that made UHF power transistors, mostly for military communications and radar. I also do PCB layout, including mixed-signal, with low-frequency analog, 2.5GHz RF, chip antenna, digital, and switching power supplies on the same board, and the signals from one section cannot be getting into another or you'll have a mess. On the last one of this type that I laid out, the performance was far better than the client expected. They were using an ANT IC and the manufacturer recommended a particular antenna design printed on the board, but I proposed a particular chip antenna to replace it to get a more spherical radiation pattern and use less board space. The result was an RF range was 20 times what the ANT IC's manufacturer said we would get. They were blown away, but the client was also happy because now they could reduce the RF output power and make the battery last longer. I calculate for filters, transmission-line impedances, Smith-chart calculations, propagation delays, etc., and never need very many sig figs.