Hi,
I’m using KiCad 8 up-to-date in Linux Mint 21.3.
Downloaded the symbol for the MMBF5484 from various library suppliers. All provide a symbol representing a MOS-FET. But MMBF5484 is a JFET.
Tried to modify the parent of the 5484 symbol (e.g. by BSR56) in properties. But the parent field is greyed out and down arrow shows nothing.
Also tried to copy the BSR56 symbol in the same sub-library as 5484. Still the same issue.
How could I wake-up the feature and define a new parent to replace that faulty symbol?
Don’t try to make any changes in KiCad standard library. Copy symbols to your personal/custom library and make changes there.
From your post, I am unsure whether you are trying to edit the KiCad built in/standard libraries.
Copy the “Device” library to a personal folder, rename it and add to your library list…
Then copy the generic JFET symbol to make your own.
Check the FAQ section, there are a couple of entries on how to handle personal libraries.
The standard libraries are “read-only”!
MMBF5484 is located in Projet Specific Libraries, not in Global Libraries. What is even stranger the library holds a MOS-FET symbol, where the schematic shows a JFET. Banging my head against the wall…
My purpose is not to make my own component when one exists on the net (octopart, snapEDA,…). Will only do so if nothing available (too much time consuming). My guess is that a symbol can be edited/replaced in KiCad.
But OK I will read your suggested FAQ’s.
Good idea.
Concerning “Project Specific Libraries”, they’re just that. A subset list of the standard libraries that you’re using and thus also read-only. They’re not personal libraries.
I’ve never understood this functionality myself and never use it. I think it’s a remnant of an early version of KiCAD.
Just copy the libraries you need to a personal library folder and take it from there.
And what outside library providers deliver is certainly not a KiCAD problem!
PS: The “Device” library part “Q_NJFET_DSG” would be the part you need, I think.
The main problem with kicad is replacing the library format once a year… Many tools stop working, as do services for searching for components; in some cases, double conversion between the old and new format helps, but it is not always painless… In general, library management is a weak point with very slow development IMHO
- Open Symbol Editor
- Scroll to Q_NJFET_DSG in Device Library
- Right click, Save Copy As
- Select the Personal Library in which you want the symbol saved.
- Type MMBF5484 into the name box
- Click Save.
Job done.
Maybe takes two minutes (allow one minute to scroll through Device Library 
)
Creating the symbol in a personal library is a lot quicker than going to the Kicad Forum and creating the Opening Post. 
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Agree 
Project Specific Libraries are created and used exactly as Global libraries EXCEPT they can only be found and used when the project to which they are attached is open. This sort of sounds OK until you wish to reuse a part which you think you placed in a project library two years and 20 projects ago.
Good luck finding it.
Even then, the part, when and if found, really needs to be then placed in a global library so it can be reused.
All in all, a very messy and time consuming business. 
Of course, if you don’t want libraries cluttered with symbols and footprints you will never use again, they have a use.
The only irksome task, I find, is adding Personal Libraries to the Global Library lists at every major release.
I just switch off the brain and click for about 10 minutes to reload the 50 odd symbol and footprint libraries I use; while thinking that if this is the biggest problem I encounter with an upgrade, the program is not too bad.
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You can do this much easier and quicker if you use a source code merge program like meldmerge to copy lines from one library table to another. Because you see the actual text during the merge, small syntax changes during KiCad version updates can be fixed too.
Thanks Paul.
I’d thought about finding something a little less monotonous; but, that program will probably be used once a year to save 5 minutes.
By the time I remember which program to use and then try to remember how to use it, well … 
And then you find that the third party symbol is the wrong KiCad version, off grid or has other errors.
Making your own symbols is so easy.
2 Likes
I was always surprised how Linux users said that typing 100 commands in the terminal is much better than two clicks on the exe
In fact, once a year there is a turning point in your developments on old projects, just look at the GitLab library errors, you have to edit the 3D models out of place and this must be taken into account during the transition
I was always surprised how Linux users said that typing 100 commands in the terminal is much better than two clicks on the exe
You can type those 100 commands into a file and it does same as the exe (you can double click it now). But with more flexibility for you in the future. Technology works that way either you get what you get or you need to do much of the heavy lifting yourself.
Which is better depends on which side of the graph bellow you expect to be
For something that takes 1 minute to do by hand yearly, you should afford to spend 5 minutes to automate and its still somewhat sane.
Thanks to all contributors.
My conclusions would be:
- on an operational point of view libraries design show up complex ergonomics, spread over many menus, preferences, windows, folders, that should be thought again from scratch, not by developers themselves but user-driven (“the best ergonomics are when you don’t have to RTFM, nor require geeks”),
- documentation should focus on it meanwhile,
- library updates should allow automatic relocation and integration of user added libraries,
- the libraries are definitely THE very weak point of Kicad over its evolution,
- the project manager(s) should take this into account.
My modest attempt of contribution to improve this fantastic piece of software…
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