Peter and list members, Related to this subject, many years ago one of the electronics magazines published (in text format) a Basic program by Jan Axelson that calculates standard resistor values for any desired ratio. Either 5% or 1% values can be calculated.
Some years later I compiled it into a small (less than 40k) DOS executable using PowerBasic. I still have the program. If someone has space on a web site or other means to make it available to list members I would be glad to email them a copy. I don't have the means to send it to lots of people if there were a huge response. Scott B. Lacey On 13 Mar 2007 at 8:24, Tarver, Peter wrote: > An off-topic question that hopefully someone can shed a little light > upon. > > I have wondered for as long as I've been involved in things electrical, > why standard component values are what they are. Text books are of no > use and I've done more than a few internet searches on this in the last > ten years (or so; maybe I've used the wrong search terms, but I haven't > found an answer). I'm interested to hear what others might know or > think about this arcane topic. > > It's probably lost to history now, but it may well be based on some > limitations of physical characteristics of early devices or one > manufacturer dominating the early production of components and they had > some idea that they could sell more components if they were in strange > increments. Or maybe there's a mathematical reason that hasn't occurred > to me, like some arithmetic progression, or even simple phobias or > prejudices. > > Maybe someone gave it the deepest thought and surmised that particular > values would yield the minimum of mixing of components in > series/parallel combinations. Maybe they're still laughing from the > grave. > > > Regards, > > Peter L. Tarver > [email protected] > > CONFIDENTIALITY > This e-mail message and any attachments thereto, is intended only for use by the addressee(s) named herein and may contain legally privileged and/or confidential information. If you are not the intended recipient of this e-mail message, you are hereby notified that any dissemination, distribution or copying of this e-mail message, and any attachments thereto, is strictly prohibited. If you have received this e-mail message in error, please immediately notify the sender and permanently delete the original and any copies of this email and any prints thereof. > ABSENT AN EXPRESS STATEMENT TO THE CONTRARY HEREINABOVE, THIS E-MAIL IS NOT INTENDED AS A SUBSTITUTE FOR A WRITING. Notwithstanding the Uniform Electronic Transactions Act or the applicability of any other law of similar substance and effect, absent an express statement to the contrary hereinabove, this e-mail message its contents, and any attachments hereto are not intended to represent an offer or acceptance to enter into a contract and are not otherwise intended to bind the sender, Sanmina-SCI Corporation (or any of its subsidiaries), or any other person or entity. > _____________________________________________________________________________ > Scanned by Sanmina-SCI eShield _____ _______________________________________________________________________ > > - > ---------------------------------------------------------------- > 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 ______________________________________________________________________ This email has been scanned by the MessageLabs Email Security System. For more information please visit http://www.messagelabs.com/email ______________________________________________________________________
