Improved EMC performance could be sold only if consumers see a benefit. Power supply efficiency has slowly increased over the years. But the increase in oil prices, interest in 'carbon footprints', and new efficiency regulations (in the U.S., EISA 2007) has suddenly pushed this issue to the forefront. Even my wife unplugs her cell phone charger when not in use (albeit, while leaving the room light on.)
If otherwise EMC-compliant laptops intermittently re-booted because your cell phone was sitting next to them (creating large RF fields), I'll bet companies would tweak the immunity of their machines so they could advertise "IMMUNE TO CELL PHONES!" Pat Lawler EMC Engineer SL Power Electronics Corp. [email protected] wrote on 04/16/2009 11:59:22 AM: > I do not think any company is going to do the ‘we have less EMC than > brand X” for the simple reason that it just won’t work. Laptops now > days are built to be fairly rugged, but they are sold to the general > public who think precariously placing a laptop on the stove top > while checking email and making dinner is ‘normal’ use. Or who > perhaps think that cleaning the fan area is just too much work and > ‘hey these things are supposed to work like this’. Of course you > then have the cleannicks who tear apart their laptops or desktops > routinely to ‘clean’ the dust out. I think I fall into that > category. Labs may even have a worse time as they open these things > probably on a routine basis for various reasons from putting test > boards, WLAN transmitters or other ‘support components’ inside to > make the test suitable. Cables are also routinely plugged and > unplugged. When running a test lab I even had customers that > carried the laptop computer by the cables getting it out to the OATS > for testing. There it was, in all its glory dangling, swinging, > bouncing and flopping around. > > > > All of this to say that buying a pristine laptop out of the box with > all EMC fingers in place, all shielding in place and all other EMC > fixes used to make it compliant in place is different than using a > hard handled PC for compliance testing. You cannot expect a laptop > or Desk top to maintain all of the originally testing compliance > margins after opening is up even once, how can you expect it to be > complaint after many openings, fiddling and fudging? > > > > This has always been and probably will continue to be a problem > child for compliance testing, but getting, keeping and maintaining a > compliant laptop or Desk top for compliance testing lies in the > world wishes. If you could get a laptop or Desk top that actually > met compliance limits, keeping it in that state would probably cost > you more than simply going out and buying a new one every once and a while. > > > > Dennis Ward > Director of Engineering > American TCB > Certification Resource for the Wireless Industry www.atcb.com > 703-847-4700 fax 703-847-6888 > direct - 703-880-4841 > > > > From:[email protected] [mailto:[email protected]] On Behalf Of Brent G DeWitt > Sent: Wednesday, April 15, 2009 4:25 PM > To: 'Price, Edward'; [email protected] > Subject: RE: [PSES] SV: "Quiet" Laptop > > > > The rate of laptop model replacement by the manufacturer makes it > very difficult to recommend something that you can still buy by the > time the EMC community has had enough time to seriously evaluate > it. I think Ed’s view on the hopelessness of seeing a manufacturer > actually advertise EMC/EMI performance would only happen to products > targeted to the paranoid financial market, and I haven’t seen any of > that. In a previous life we went out and searched eBay to find > laptops that had been discontinued by the manufacturer that we knew > to be clean. > > > > Good luck! > > > > Brent DeWitt > > Westborough, MA > > > > From:Price, Edward [mailto:[email protected]] > Sent: Wednesday, April 15, 2009 5:11 PM > To: [email protected] > Subject: Re: [PSES] SV: "Quiet" Laptop > > > > > -----Original Message----- > > From: [email protected] [mailto:[email protected]] On Behalf > > Of Grasso, Charles > > Sent: Wednesday, April 15, 2009 12:50 PM > > To: [email protected]; Piotr Galka > > Cc: EMC-PSTC; John Woodgate > > Subject: RE: SV: "Quiet" Laptop > > > > I sincerely hope that you statement: "Finding a quite laptop > > or hub seem to be almost impossible" is wrong! After all > > there are many large laptop manufacturers spending zillions > > of (in our case) dollars to meet the EMC requirements.!! > > True, but who markets their product with any claims of EMC > excellence? We all may be spending big bucks in our compliance > efforts, but all we ever do is slip a required statement in our > Users Manual or mold a logo on the bottom of our case. > > Instead of quietly muttering that "we meet the minimum legally > required standards," is anybody daring to say something like "Our > Wonderbox has 14 times less annoying electronic radiation!" Or how > about something like "Our Wonderbox still keeps working when others > have crashed; we built this thing to handle RF noise 3 times > stronger than the government said we had to!" > > Now I doubt your marketing would ever let you get away with anything > like that, because claiming how great you are, even if it's true, > means alerting the customer to certain problems in life. Marketing > usually doesn't want customers to think about problems when they > sing their sales pitch. We will have to wait for some maverick > company to try this angle; who knows, it just might work. Certainly, > RF engineers have a couple of brand names in their head when they > think about low-noise pre-amps, so maybe the public reputation of an > EMC tough product is possible and desirable. > > The original poster was asking an interesting question. While you > shouldn't choose a "lab queen" product, what's wrong with choosing > the quietest among the major brands? But even in this knowledgeable > forum, we really didn't have an answer. I'll pose a question; > suppose, for your own personal desires, you wanted a very low- > emission gadget. If you went to any number of major consumer > electronics websites, and looked for compliance data, do you think > you would find even one that offers real performance data, not just > a bland statement of "meets the minimum requirements," to let you > make any intelligent choice? > > Right now, even we experts can't offer a good answer to the poster's > question, because we have no qualitative data. > > Ed Price > > [email protected] WB6WSN > > NARTE Certified EMC Engineer > > Electromagnetic Compatibility Lab > > Cubic Defense Applications > > San Diego, CA USA > > 858-505-2780 > > Military & Avionics EMC Is Our Specialty > > - > ---------------------------------------------------------------- > This message is from the IEEE Product Safety Engineering Society > emc-pstc discussion list. To post a message to the list, send your > e-mail to <[email protected]> > > All emc-pstc postings are archived and searchable on the web at > http://www.ieeecommunities.org/emc-pstc > Graphics (in well-used formats), large files, etc. can be posted to that URL. > > Website: http://www.ieee-pses.org/ > Instructions: http://listserv.ieee.org/request/user-guide.html > List rules: http://www.ieee-pses.org/listrules.html > > For help, send mail to the list administrators: > Scott Douglas <[email protected]> > Mike Cantwell <[email protected]> > > For policy questions, send mail to: > Jim Bacher <[email protected]> > David Heald <[email protected]> > > - > ---------------------------------------------------------------- > This message is from the IEEE Product Safety Engineering Society > emc-pstc discussion list. To post a message to the list, send your > e-mail to <[email protected]> > > All emc-pstc postings are archived and searchable on the web at > http://www.ieeecommunities.org/emc-pstc > Graphics (in well-used formats), large files, etc. can be posted to that URL. > > Website: http://www.ieee-pses.org/ > Instructions: http://listserv.ieee.org/request/user-guide.html > List rules: http://www.ieee-pses.org/listrules.html > > For help, send mail to the list administrators: > Scott Douglas <[email protected]> > Mike Cantwell <[email protected]> > > For policy questions, send mail to: > Jim Bacher <[email protected]> > David Heald <[email protected]> - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to <[email protected]> All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc Graphics (in well-used formats), large files, etc. can be posted to that URL. Website: http://www.ieee-pses.org/ Instructions: http://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas <[email protected]> Mike Cantwell <[email protected]> For policy questions, send mail to: Jim Bacher: <[email protected]> David Heald: <[email protected]>
