Adding Ohm symbol to schematic

Schematic
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Using 5.1.12 and wondering if there is a way to add the ohm symbol to resistor values.
Thanks,
OtG

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Copy this Ω.

Rec 0002

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Using Linux Mint 20.2, btw.

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Typing different unicode characters is an OS thing. Search for example for “type unicode characters linux mint”.

A common workaround is to use some application where you can select unicode characters from a dialog, like OO/LibreOffice. Or just keep in a browser tab a web page where you can do that. It’s easy to find those pages.

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Luckily Ω is part of the extended ascii table so how an OS deals with UTF8 and all that shouldn’t compound this

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Be careful not to select Omicron symbol. :frowning:

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That would be a normal “o” or “O”. :nerd_face:

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Adafruit sells a cute little ruler/keyboard that can type the Ω and ” symbols, but unfortunately it only works on Windows.

On Linux, I recommend the kcharselect application.

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As mentioned above, besides using the charmap command (Win+R), on some versions of Windows and in some apps, holding down left Alt, then typing 8486 or +2126, all on the numeric keypad, and then releasing Alt, produces ℩ (Ohm Sign) and 181 or +b5 produces ” (Micro Sign), which German and newer French keyboards have a key combination for already.

There are also 937 or +3a9 Ω (Greek Capital Letter Omega) and 956 or +3bc Ό (Greek Small Letter Mu), which might look different with different fonts.

I also like to use 8239 or +202f (Narrow No-Break Space, nnbsp) between quantities and units, so that there is no line wrap in between (unfortunately, the forum software here replaces it with a regular space).

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Why do you want to add these?

I consider it a waste of time (and also a bit of screen area).

I like the compact notation, where a 4700 Ohm resistor is simply written as 4k7

This method is quicker to enter, and you never have to add dots in numbers (which should be comma’s here in europe).

This notation is also quite common, also with electronics shops and PCB assembly houses. Adopt it and take some time to get used to it. If you start adding “weird” characters, there always is a chance they get fouled up. For example if you use external tools or spreadsheets to create or modify your BOM. If you fancy Ohm symbol gets replaced by such an script then you can get very unpredictable results. It may even get replaced by the letter O, which might be mistaken for the number 0.

Schematics should be made by and for engineers and unambiguous. Making them “beautiful” is not a priority (Making them easy to read is a priority though).

6 Likes
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@OscarTheGrouch

”” & ΩΩ are easy on Mint.

Bottom right of screen near clock you will find three English keyboards. A US, an Australian and a UK.
Select UK and Show Keyboard Layout.

RH Alt + M = ”
RH Alt + Shift + Q = Ω

so, you can have: 49⅝”F & 841⅞Ω :slightly_smiling_face:

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RH Alt + M = ”
RH Alt + Shift + Q = Ω

That seems to work with Fedora 35 and KDE, so probably not only Mint specific.

Edit: I should of course have added that this is in swedish (=finnish) keyboard layout

I haven’t tried out other keyboard layouts to see if they work the same.

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@hmk

The OP states using Mint and I also use Mint. I didn’t look further.

Good to know Fedora 35 & KDE also work.

I wonder what else has a UK keyboard giving the same result?

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Current desktop operating systems usually support an emoji input method which will let you search emojis (and other symbols) by name and/or chose them from a table.
On Windows, press win + . to open this panel.
On Linux using IBus, press ctrl + . (or ctrl + shift + e for some older versions) to enter emoji input mode, indicated by an underlined e. Type whatever you want to search for and press space to open the panel. This needs the appropriate package(s) like ibus-table-emoji or similar, depending on your distribution.

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On my Debian Linux machines, I run “xkbsetup -variant mac” which remaps my keyboard to let the right-Alt access a bunch of symbols, including ” and Ω.

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Adding non-standard symbols is likely to break less well tested software. A Ω symbol hosed an early BOM script I was using and adds an unnecessary extra point of failure. Fine to add it to documentation and text but I would steer clear of using it in any file that will need to be parsed by an external program.

EDIT
Here, look what happened in another recent post - and this is in a well tested program & likely at UTF-8 issue. Now, I’m not saying it was related to an Ω or a ” symbol but it increases your chance of problems.

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RH Alt + M = ”
RH Alt + Shift + Q = Ω

This also works in Ubuntu with UK keyboard.

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I second the posts that suggest to avoid such characters in symbol fields. In graphics text, fine. In my early days I religiously added Ω and F to component values. I did run into problems with an external program. Many programs out there haven’t properly transitioned from Latin-1 to UTF-8. Furthermore as mentioned, it just lengthens the text on the schematic. There is no ambiguity anyway.

But UTF-8 characters elsewhere, go for it. :+1::smiley_cat:

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The immediate need is to produce a document to illustrate to my students how to solve a Super Position problem. It just simply looks better to have Ohm symbol on the schematic.

All of my other schematics I’ve only needed to make PCBs from them and extracting a simple BOM, I see no issue with having the symbols in the schematic.

Thanks all for the reply’s, I’ve used the Character Map program to insert them without any problems.
OtG