Brian, You are absolutely correct. It is most difficult to specify the operational specifications of electronics in regards to transients and other anomalies.
I deal with engineers of two different schools; one approach is to specify and document all the requirements, which in most cases is very difficult to do, OR those who just test and qualify. I'm a believer in the later (because we live to test, test, test). We are blessed by having a corporate compliance lab that can qualify almost any component or prototype setup in a few days. Our testing finds a lot of problems up front and engineering has come to rely on this testing to insure a compliant final design. Brian ____________________Reply Separator____________________ Subject: RE: Burst and surge tests Author: [email protected] List-Post: [email protected] Date: 5/18/2006 5:09 PM Good People I speak only for myself, and perhaps for my dog, but definitely not for my cat or employer... It is difficult for a component SMPS mfr to say that the outputs will stay within specified tolerance *DURING* these tests; because we cannot control the ultimate end-use installation. There are, in fact, some end-use constructions that will probably not be able to pass either Criterion, for any reasonable-cost SMPS. luck, Brian > -----Original Message----- > From: [email protected] [mailto:[email protected]]On Behalf Of John > Woodgate > Sent: Thursday, May 18, 2006 7:31 AM > To: [email protected] > Subject: Re: Burst and surge tests > > > In message <[email protected]>, dated Thu, 18 May 2006, > [email protected] writes > >So, we have specified that the output of power supplies must > not cause > >our electronics to malfunction during the 4-4 or 4-5 tests. > We specify > >that the DC output of a power supply can not go "out of spec" during > >these tests. > > Effectively, you are applying Criterion A instead of B, and indeed > that's usually very difficult to do. That's why Criterion B exists. > > But there may be no other solution if you buy-in the power supply, > unless you can co-operate with the supplier to agree a less stringent > requirement that does not result in your own electronics being > compromised. > -- > OOO - Own Opinions Only. Try www.jmwa.demon.co.uk and www.isce.org.uk > 2006 is YMMVI- Your mileage may vary immensely. > > John Woodgate, J M Woodgate and Associates, Rayleigh, Essex UK - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. Website: http://www.ieee-pses.org/ To post a message to the list, send your e-mail to [email protected] 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] All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. Website: http://www.ieee-pses.org/ To post a message to the list, send your e-mail to [email protected] 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] All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
