search

KiCad / kicad-symbols

Official KiCad schematic symbol libraries for Kicad 5
https://kicad.github.io/symbols
Other
700 stars 747 forks source link

Resistor network/array symbol issues #1406

Open evanshultz opened 5 years ago

evanshultz commented 5 years ago

From https://github.com/KiCad/kicad-library-utils/pull/256.

And a few minor notes which I plan to turn into an issue but perhaps you want to comment on now (?):

  1. The R_Network* symbols don't describe the configuration of the resistors. I would call them "bussed".
  2. Similar to an above point, "R_Pack" doesn't tell the configuration. I would use the word "isolated".
  3. The points above refer to inconsistent naming. Perhaps we should define a naming convention like R_Network<number of resistors>_<configuration such as Bussed, Divider, or Isolated>[_SIP]? We could replace Network with Array for brevity.
  4. The divider resistors are named by the number of divider elements while the others are named by the number of resistors. I don't see this as helpful and it's unclear to me what the naming means without seeing the symbols. It also wouldn't work to describe the "8 terminal, 6 element" parts at https://www.susumu.co.jp/common/pdf/n_catalog_partition02_en.pdf#page=4 versus what we have now (maybe these are uncommon and we don't care?). DigiKey just goes by the total numbers of resistors in the part (symbol), regardless of the configuration, and that may be a better way to go. I've incorporated that above.
  5. Why do the divider symbols end in "_SIP"? There is only one version of divider symbols so this doesn't add anything.
  6. It appears "_SIP" for the "Pack" resistors relates to the pinout of the symbol, but I associate "SIP" with the physical package which, in KiCad, is separate from the schematic symbol? Perhaps there's a better word to use if we want to refer just to the symbol pinout? (I can only think of "Inline" right now but I don't love that.)
  7. I don't know how common the usage of this configuration is, but DigiKey turns up over 1000 parts that are 2 resistors in a divider configuration, such as http://www.vishay.com/docs/60001/mpm.pdf. No other dual-resistor configuration they list is missing from the script. Perhaps the divider script should pop out a dual-resistor symbol?
  8. The ref des and value could be oriented right-side up, stacked, and placed above (if there's not pins) or to the right of the symbol. The auto-place algorithm may move them around but if this feature is turned off in KiCad at least the text is not on its side which is ugly and atypical for the library.
  9. The script updates don't generate the US resistor symbols.
herostrat commented 5 years ago

I agree, the naming is not optimal atm.

  1. and 2. There are a number of commonly used terms, and I strongly agree to include them in the name!

    • Bussed (as you correctly said) / can be seen as terminated
    • Isolated (as you correctly said)
    • Dividers (already in the official library) / can be seen as dual terminated
    • Pi-type
    • ...

  2. I agree. Also, I do not know for sure and could not find good reference, but I think there is a difference between network and array. All arrays I saw (e.g. in the Vishay catalog) are the "typical" resistor SMD package and networks are SIL and DIL.

  3. Agreed, but only because I can not think of a better way to describe them. My (own) favorite way of thinking is usable individual "elements", because it leaves out the need to know how many r and c are inside the array/network. But this is also not optimal I guess.

  4. and 6. I cannot see why the SIP is and should be there. Than again, I could miss something.

  5. Afaik they are not hat uncommon, because you get the same thermal drift if they are on the same element. Also the adjustment via laser can be way better in that cases. So I think we should include them!

  6. NC

  7. NC