In message <4946d305.3020...@sbcglobal.net>, dated Mon, 15 Dec 2008, Fred Townsend <ftowns...@sbcglobal.net> writes:
>The academic view is strange. I don't think that 'strange' is the right word. >I will never forget an advanced amplifier design class where I was >supposed to calculate the proper value of a bypass capacitor. The >'correct' answer was 87.5 microfarads. Never mind you can't buy an 87.5 >uF cap and therefore the design is unrealizable until proper >tolerancing is applied. Academics, even teaching engineering, mostly do science rather than engineering. They don't bother with practical details, and in many cases, don't even know about what standard component values are available. I've met two 'engineering graduates (one English, one French) who calculated resistor values to 1 part in 10^4 or so, and made the values up from series-parallel combinations of standard parts. They had never even HEARD of tolerances, let alone preferred values. Science says '87.5 uF'; engineering says 'Maybe a 100 uF will do, even at -20% tolerance. Let's try it.' -- OOO - Own Opinions Only. Try www.jmwa.demon.co.uk and www.isce.org.uk All these closing-downs have been caused by dozing clowns John Woodgate, J M Woodgate and Associates, Rayleigh, Essex UK - 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 <emc-p...@ieee.org> 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 <emcp...@ptcnh.net> Mike Cantwell <mcantw...@ieee.org> For policy questions, send mail to: Jim Bacher: <j.bac...@ieee.org> David Heald: <dhe...@gmail.com>
