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newRPL: [UPDATED April 27-2017] Firmware for testing available for download
08-14-2016, 11:43 AM (This post was last modified: 08-15-2016 12:09 AM by Vtile.)
Post: #378
RE: newRPL: [UPDATED July-25-16] Firmware for testing available for download
(08-13-2016 11:35 PM)matthiaspaul Wrote:  
(08-13-2016 05:28 PM)Vtile Wrote:  I think ( or "I quess" depending which is less affirmative) if someone is using the F for capacitor or H for inductor are not familiar with the system.
Not sure about that... Similar to "u"/"U" and "µ", I assume one reason to use "R" instead of "Ω" is that the glyphs look similar and that "Ω" is often difficult to type or not available at all (in CAD software even less so than in text processors). "R" expanding to "resistor" is certainly a nice (and influential) coincidence as well, but if that would have been the primary reason for the choice of that character, it would indicate that someone mixed up quantities with units. So, there are good arguments for both. ;-)
Your explanation of similarities between glypths of R and omega are indeed interesting and now when you pointed it out I can see the similarities. You are correct there is a good argument for both Big Grin This would need more digging to the history of notation in electric calculus itself.
(08-13-2016 11:35 PM)matthiaspaul Wrote:  
Quote:As that british standard [...] indicates that R (resistance) is user for Resistors and C (capacitance) for Capacitors.
Well, that's just the question. ;-) Which character is used in BS 1852 as "factor 1" decimal separator in capacitance values? If I understood you correctly, you don't have the actual standard in front of you either, or could you look it up in the meanwhile? Searching the net, I could not find that being answered with explicit reference to that standard as the source...


You understood my gibberish correctly, indeed I do not have the standard here (or anywhere else) with me, so that is based on those wikipedia and other internet finds at that time. I might made a too big assumption about the factor 1 marking for C, but on the other hand I can not see the unit explanation as a truely solid explanation. That assumption is made because the L.R.C markings are so widely used in electronic engineering, ie. LCR-meters (no RFH-meters), LC-circuits (no FH circuit) and so on. How it were approx. 1900 .. 1950s before Giorgi system aka mksA system, remains still a questionmark.

This starts to go way too much offtopic for a newRPL topic so maybe it should be branched out to its own.

  1. Colour Code for Fixed Resistors for Telecommunication Purposes (B.S. 1852: 1952).
  2. BS 1852:1975, IEC 60062:1974 Specification for marking codes for resistors and capacitors

EDIT: I created a new spinoff thread for this subject:
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RE: newRPL: [UPDATED July-25-16] Firmware for testing available for download - Vtile - 08-14-2016 11:43 AM

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