How to add the Ohm symbol to your schematic. - Page 1
Forum section: electronics / general

author: jamiechi
author_rank: Contributor
timestamp: November 12, 2013, 02:54:44 am
content: This should apply to all versions of Altium since Summer 09.This also assumes you are using Win7, Vista, or WinXP. It should also work in Win8. (I don't remember where the program is in WinXP.)1.) Open the Character Map application. In Win7 just type it in the search box on the start menu.2.) In Character Map, in the Font selection go to Times New Roman.3.) Scroll down until you find the Omega symbol and select it in the main window of Character Map.4.) Press Select, then press the Copy button. (The symbol should be in the edit box.5.) Go to the schematic editor and edit one of your resistor symbols. Paste the Omega symbol into the Value edit box after the other stuff, such as 1K?.I saw the old post about this, but I thought it would be better to create a new thread. I was not sure about the policies concerning bumping old threads.

author: IanB
author_rank: Super Contributor
timestamp: November 12, 2013, 03:02:43 am
content: I think it shouldn't be necessary to show the unit of measure next to the value since the symbol should make it clear what the value refers to. (For example, engineering drawings may say "all values in mm" and then just show the numbers on the diagram.)So for a resistor value of 1 kilohm you would just designate the value as 1k0 on the diagram. Similarly for a 2.2 nF capacitor you would show the value as 2n2.

author: sacherjj
author_rank: Frequent Contributor
timestamp: November 13, 2013, 06:38:51 pm
content: I have gotten used to Alt+codes for some common, like Alt+0181 for µ and Alt+234 for ?. These seem to work in Altium fine. Although I generally use the 'R' and leave off Ohm.1.2 ? -> 1R21.2 K? -> 1K21.2 M? -> 1M2u along with n and p tend to work fine when you don't want to bother with µ.Edit: Interesting. The forum software is converting the omega symbol to ?. Those should read as the omega symbol.

author: Monkeh
author_rank: Super Contributor
timestamp: November 13, 2013, 06:47:31 pm
content: Quote from: sacherjj on November 13, 2013, 06:38:51 pmYay, character encodings.Also yay, unpredictable Windows, alt+234 produces Û.

author: IanB
author_rank: Super Contributor
timestamp: November 13, 2013, 06:48:33 pm
content: Quote from: sacherjj on November 13, 2013, 06:38:51 pmUnfortunately, it does that. The encoding of the character is lost somewhere along the line.

author: Monkeh
author_rank: Super Contributor
timestamp: November 13, 2013, 06:49:35 pm
content: Quote from: IanB on November 13, 2013, 06:48:33 pmCharacter encoding, unfortunately, is something most people never seem to quite understand.

author: Neilm
author_rank: Super Contributor
timestamp: November 13, 2013, 06:53:31 pm
content: In Word, I seem to recall typing 03a9 then pressing ALT-X will produce the ohms symbol.

author: Monkeh
author_rank: Super Contributor
timestamp: November 13, 2013, 06:55:12 pm
content: Quote from: Neilm on November 13, 2013, 06:53:31 pmU+03A9 being the code point for an uppercase Greek Omega.

author: free_electron
author_rank: Super Contributor
timestamp: November 13, 2013, 08:08:13 pm
content: DO NOT USE THE OHM SYMBOL !!!!!DO NOT USE DOTS OR COMMAS FOR FRACTIONAL VALUES !!!it is too easy to mistake it for a 0 , especially when printed small.10R 10 Ohm1R5 1.5 Ohm1K5 1.5KiloOhm1M5 1.5 MegaOhm0R22 0.22 Ohm

author: jamiechi
author_rank: Contributor
timestamp: November 13, 2013, 11:01:50 pm
content: I don't use it for component parts, but sometimes it is nice to show the omega in documentation notes on the schematic. I just showed how to do it because someone else asked for it in another thread. I agree, especially on the pcb silk screen, it is not a good idea to use it for parts values. I was sure it looked like an omega symbol in the preview box.I never use the alt+ any more. There are too many applications in Windows that use different character sets.

author: sacherjj
author_rank: Frequent Contributor
timestamp: November 14, 2013, 12:45:02 am
content: Quote from: Monkeh on November 13, 2013, 06:47:31 pmNice. Sigh. I'll probably never pack in the Unicode shortcuts... To little space left in my brain.