Trade paper review, June 2007

I have been sifting through my stacked-up trade papers since I got back from Vietnam last week What caught my eye:

Safe Charging, an article from Maxim in Appliance Design. It talks about charging Li-Ion batteries and the things you have to know.

The AD8210, a nice current-sensing part from Analog Devices. It works in both directions, and has a 500kHz bandwidth. It has a CMRR of 120 dB, that is a million to one and that is pretty good; I don’t care who you are.

An article about energy conservation written by a guy from the EPA instead of some company trying to sell you things, in Electronic Products.

An article from Wards Auto World about electronics in automobiles, by freelancer Randy Frank.

I noticed an article about WiMedia UWB and WiMax interference issues in Wireless Design and Development. The Google search I did also showed it published at CMP’s Wireless Net Design Line. Then I found the original that has a few more figures at the author’s company website (pdf). BTW, people, EDN will not publish anything that has been published before, although you are welcome to publish it afterward the way Linear Tech does with Jim Williams articles that they then make into application notes. So if you have something already published please don’t send it in to us like it is new material, it is very easy to check. This particular article is written by someone who makes WiMedia and WiMax stuff so, surprise, he concludes that there will be no interference from these radios that spread their bandwidth over tens or hundreds of megahertz on top of existing bands already in use. I sure hope he is right, my research for my recent article about wireless machine to machine systems showed there were some severe issues at 2.4 GHz and our Executive Editor Ron Wilson told me that I could voice my concerns as long as I had good research. My pal and Analog Fellow at National Semiconductor, Dennis Monticelli is very concerned over things like broadband over power lines. These schemes are creating all kinds of interference in the ham bands and the FCC does not seem to be very concerned.

Another good bit from Wireless Design and Development is an article about tradeoffs between three-phase and single-phase power systems. The same article, from the company the author works from is here (pdf). The author, from good old Transistor Devices, says that if you are trying to do power factor correction it is easier to use single-phase power. Maybe, but I sure like the smaller hold-up caps that three phase provides. Maybe a quasi PFC that only works for 60 degrees per phase. And for bogus patent of the month I submit this one from IMB where some Skippy hangs comparators off the line to sense zero crossing. This is not novel and is obvious to one skilled in the arts. It should just be coming off its 17 year run, if that is how long patents last these days. And do check out the Google patent search feature—hit the “more” link next to the Google search box and you get the full patent and you don’t even have to download a tiff viewer like with the USPTO site. Yeah Google.

Wireless Design and Development also had a product feature on this neat RF switch from TeraVicta. Now this is MEMs that has a real comparative advantage. 26.5 GHz, yeah TeraVicta.