Alternate resistor symbol (KiCAD evaluation for company use)


#1

New to KiCad. As a cost saving strategy, my employer is looking to use more open source tools. KiCad seems to be the most recommend open source schematic capture tool.

When I made my presentation, some of the managers - and engineers - complained that the symbol for resistors is a rectangular box instead of a “zig zag” line:

I tried looking at some of the additional libraries, including “pspice” and others, but didn’t find resistors using that symbol. I also tried to look at kicadlib.org and kicadcloud.com, but those websites seem to be gone.

While I assume we could create new (or edit the existing) resistor symbols, I wanted to ask if there’s already a library with that symbol for resistors.

Thank you.


#2

It’s a less than 5-minute job to make another resistor symbol. After you do that, make sure to fire everyone who thought this was a substantive issue. That’ll save you more money than any open source software ever will.


#3

The box has been the preferred symbol for at least 30 years, less effort in the drawing office back then and no confusion with inductors


#4

The bold-face in the above quote is the more significant financial question: “How difficult is it to add new symbols and footprints to the existing libraries?”. The great majority of commercial users of KiCAD - or ANY layout program - will create and maintain their own libraries. For every board I’ve ever done, whether on KiCAD or several of the other $$$K products, the “library work” has taken anywhere from 10% to 90% of the total effort. A proper financial evaluation of KiCAD needs to ask, “How much time, effort, and resources are required to create, document, and maintain the libraries?”.

Well, I will concede the point on the inductors. Did you say 30 years? Old habits die hard: here in the U.S., the jagged line symbol is still the more common representation by a very large margin.

The jagged-line symbol is the only symbol I have used in KiCAD for almost 2 years now. (And, the symbol I used on more than 95% of the schematics I drafted with other EDA tools before coming to KiCAD.) On my machines, that symbol is called “R_US” and it lives in the “Passive_RLC” library. (I maintain my own local libraries.) I’m certain that I took it from somebody’s KiCAD Library repository. I don’t recall drafting it myself, and I would have been rather reluctant to do so during my early days with KiCAD. But I don’t know where I got it. Can anybody help?

Dale


#5

So much this. Anything else is hot air.

Also, even more important questions - what features does your workflow need which the ECAD software should contain.
Someone started a thread on those issues over a year ago:


#6

Long ago KiCad used the ANSI zigzags and switched to IEC boxes, see this thread, discussing bringing them back


Hint - CERN is in Europe, so ANSI is irrelevant to them.
There is nothing stopping you creating your own Device_ANSI.lib, though I recommend that you keep the pins in the same place to simplify schematic conversion


#7

The library is not managed by cern :wink:

If somebody would create a pull request for a resistor in the American style i bet it would be accepted. As long as it’s measurements are compatible to the current resistors i see no problem with it. I’m not sure what @SchrodingersGat or @jkriege2 think about that though.

Because no two symbols should have the same name it would need to be named something like R_IEEE or R_US, …


#8

I guess the zig-zag represents a wirewound resistor?

Perhaps one could delve into the KiCad archives to find the zigzag, but it wouldn’t take long to create new symbols.


#9

We discussed this (a tiny bit) when I overhauled the device.lib … and it was decided to generally use IEC-symbols for the official libs. So I’m not so sure whether the IEEE-style would be accepted … please remember that this does not only encompass the resistors, but also pol. caps, diodes, transistors, … and we would end up having to manage two sets of symbols for the same thing.

Also: As I understand it, IEC is an international norm, while the wiggly IEEE-resistors are mostly used in the US, correct? So I would say IEC is the better option for a program that is not taylored for a single market …

Any other thoughts on that?

Best,
JAN


#10

For me, it is a no-brainer. KiCad should follow the accepted international standard (IEC). Maintaining more than one standard is just a waste of time and resources.


#11

My standard resistor symbol is the zig-zag and I honestly don’t remember where I got it. I don’t think I created it.


#12

Same here. The “standard” symbol may have been that blocky-looking thing for decades, but both of us apparently went out of our way to find the symbol we’re most comfortable with.

Dale


#13

I went back to 2007-06-05 but didn’t find a zigzag symbol resistor, which is the earliest appearance of KiCad source in bazaar. I don’t know where KiCad lived before that.

I am familiar with the zigzag from my early days reading Popular Electronics, and I am sure I remember the zigzag in first version of KiCad I used. Then it changed to box, and I thought oh well, I couldn’t be bothered drawing new symbols.

Anyway, that means we have been using KiCad for over 10 years, guys :slight_smile:


#14

If there are enough users it makes sense to maintain a few different standards. (Having said that, the symbols are maintained by volunteers and the volunteers of course will only put in symbols which are useful for them.) The Russians have GOST and in the USA there are a few - some people will use IEC, others will use ASME, ANSI, or IEEE; some projects with various government departments will demand a particular standard (used to be all ASME/ANSI but both organizations have been surrendering responsibility to IEEE for the sake of reducing variation and saving the expense of this duplicate but differing work). So it’s complicated. :slight_smile: For me the schematic layout would need some changes to be genuinely compatible with IEC and IEEE/ASME/ANSI specs. At the moment we can’t really claim conformance to IEC because KiCad is using an imperial grid. So there are still some issues to work on for KiCad to be more usable in cases where the customer demands compliance to certain specifications.


#15

I went ahead and made new symbols.

Is there a place for contributed symbol libraries? KiCad came with a library called “contrib” but there was only one symbol in it.

And, as I mentioned, the kicadlib.org and kicadcloud.com websites seem to be gone.

(FWIW, our new VP of engineering likes open source. While not my place to question business decisions, I can say that official adoption of something like KiCad will help our workflow by standardizing the tool used by the designers, which will make the work of the layout specialists easier. As for what the layout specialist think, moving to any new toolset will involve a large effort, but they are more than ready move away from their current toolset.)


#16

Try “diy_rcl.lib” from https://github.com/wilywyrm/KicadLibraries

The symbol may also be in the Sparkfun libraries.

Possibly in Chris Pavlina’s libraries at https://github.com/cpavlina/kicad-schlib

Or the AB2Tech libraries at https://github.com/ab2tech/KiCad/tree/master/library

Dale


#17

The official site is kicad-pcb.org and thanks to Digikey we also have kicad.org. The website is maintained by volunteers who are also very active on the dev list. The “libraries” (footprints, 3D models, schematic symbols) are a different project and maintained mostly by volunteers who are not involved with the software development (libraries are in various repositories under github.com/kicad). The documentation program is a third project maintained by yet a different set of volunteers, with occasional input from the devs when we make some big changes and don’t forget to document them. (https://github.com/KiCad/kicad-doc)

Personally I think some effort is needed for a separate project to provide part configuration and management, but that’s a big project and most of us existing devs struggle to get much done already. (I have 2 big projects to work on within kicad and I haven’t had any time to work on anything at all for over 6 months now.)


#18

So by your own words we should expend our very limited resources by improving IEC compliance, and not getting side-tracked or effort diluted by chasing multiple regional standards.

If users want to get together and create their own regional libraries, there is no problem with that. I just don’t see any justification for official support.


#19

They can always become volunteers and provide the IEEE symbols, if that’s what they want/need.


#20

The question is whether this would be accepted into the lib … we already struggle keeping the lib in good shape and editing everything to conform to KLC 2.0 … + all the new 3D model stuff + the still open problem of CMOS/TTL-libs with their hidden power-pins …

I (personally) would like to see those more severe problems in the official libs solved/worked on, before we add doubled symbols that need to be maintained (please have a look at device.lib and switches.lib, which are the two libs mostly affected … there are loads of symbols that would need to be done for IEEE!)

Best,
JAN (one of the struggling librarians)