Green motors, copper wires and more
This month’s batch of feedback from magazine subscribers and ControlEng.com users takes on a decidedly international flavor. In addition to comments received from within North America, we’ve also received feedback from individuals in Thailand, Korea, Brazil and Nigeria. The blogs hosted on ControlEng.
This month’s batch of feedback from magazine subscribers and ControlEng.com users takes on a decidedly international flavor. In addition to comments received from within North America, we’ve also received feedback from individuals in Thailand, Korea, Brazil and Nigeria. The blogs hosted on ControlEng.com are also generating a fair share of traffic and response. Given the varied nature of the blog content — from the practical and helpful nature of “Ask Charlie” to a peek inside the inner-workings of the ISA88-Part 5 development process — it’s no surprise that we’re drawing an active response from readers. However, if we haven’t yet heard from you, it’s time to let us know what you think. If you do, your comments may appear in print... just like these folks. —The Editors
Jim H. of Richardson, TX submitted a somewhat prescient comment in response to Mark Hoske’s news posting detailing the unveiling of Ambient Corp.’s new Audeo communication appliance ( Voiceless Control, March 6, 2008 ) designed for individuals who have lost their ability to speak:
Similar experimental chips have been developed to give sight to blind people. 10 years ago, I predicted that in 15 years (i.e. 5 years from now), an embedded “human augmentation system” would be possible, complete with memory, sensors, wireless communications and neural interfaces to the brain. These systems would eliminate the need for external phones, TV and PC screens and provide bio-feedback, health monitoring and many other functions. Clearly, this would change the world as we know it and probably constitute the next great technological revolution. How far off are my predictions?
In the article Fiber optic vs. copper: 5 reasons fiber wins (January 29, 2008), Mark Hoske summarized a handy list comparing the two approaches to cabling, courtesy of CableOrganizer.com. One claim in particular, that “fiber-optic cabling poses no threat of physical injury if it breaks,” drew a couple of interesting comments.
If I switch my home to fiber for phone/tv/internet, the phone company would replace my copper line into the house with fiber. Since fiber cables don’t conduct electricity, they are safer. But when the power goes out, all phones are dead, even the old ones which don’t use house power. I do have a cell phone, but in power outages I like having my old phone powered by the phone line, and reliable. —Kevin B.
While optical fiber does not pose a fire or electrocution risk during handling while live, it can pose a serious blinding risk to the technician or bystanders if it is powered by a laser. With most lasers in fiber systems operating in the infra-red range, there is no visual indication that the fiber is powered. Even the visible spectrum systems use extremely high intensity sources. Looking into the end of an active fiber can potentially, temporarily or permanently, damage your retinas. —Robert C.
Lean and green
Charlie Masi’s February 11, 2008 edition of the “Ask Charlie” blog answered the question “ Do high efficiency motors always save energy? ” Reader Richard M. added a great perspective to the conversation with the following insight:
“One must also take into account overall efficiency. Getting 3% more motor efficiency just to connect it to a worm gear reducer with an efficiency of 60% doesn’t really get you much. And, keep in mind that all of this efficiency doesn’t come out of nowhere. There are trade offs. Increases in efficiency are sometimes gained at the cost of higher rotor inertias, which means more energy lost during startup and a load that’s harder to stop. Cycling applications should be approached with care.”