I read in !emc-pstc that Crabb, John <jo...@exchange.scotland.ncr.com> wrote (in <1D4B655D707B2549AFCD8C686631657508AC2BC2@SGBDUN200>) about 'LCD Displays and Safety' on Tue, 9 Sep 2003:
>I spoke to some committee members who seemed to think it was >included because LCDs couldn't withstand the impact test ! I believe that was the prime cause for asking for the matter to be considered. > >The real issue, however, is whether there is a hazard in the LCD display >that requires a degree of protection. I am aware of 2 possible hazards : >High voltage present at the lamps within the LCD. In all the LCDs we use >in our Automated Teller Machines (ATMs), I perform the limited current >test and prove that the circuitry used meets the requirements for a >limited current circuit. I would also conduct a short circuit test on >the driver circuit for the lamp(s) - usually an oscillator feeding thru >a transformer - but typically the power output is so low that the >oscillator shuts down when a short is applied to the output transformer. > >The second possible hazard might be considered to be the chemicals >present in the LCD. This has been the subject of some debate, the >conclusion (based on information from LCD suppliers) being that there is >no chemical hazard present. If you want any further details, let me know >and I can probably recover something from my files. These are the results of the consideration, i.e. that the fragility of the LCD does not result in a hazard. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk Interested in professional sound reinforcement and distribution? Then go to http://www.isce.org.uk PLEASE do NOT copy news posts to me by E-MAIL! This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: emc_p...@symbol.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
