Author Topic: Using the ohm symbol in schematics  (Read 9785 times)

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Offline tbscopeTopic starter

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Using the ohm symbol in schematics
« on: February 04, 2012, 06:17:59 pm »
Is it possible to use the ohm symbol in schematics?
I tried and every time I save a document and open it again, the ohm symbol is replaced by another character.
 

Offline 8086

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Re: Using the ohm symbol in schematics
« Reply #1 on: February 05, 2012, 11:19:45 am »
I believe the letter R is acceptable as a replacement, for values under 1k, and then just use k, M, etc without either R or omega.
 

Offline Psi

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Re: Using the ohm symbol in schematics
« Reply #2 on: February 05, 2012, 12:11:54 pm »
And there's the naming scheme where   1R2  = 1.2ohms   or 1k2 = 1.2kohms  etc..
I don't particularly like it, but it's quite common.
Greek letter 'Psi' (not Pounds per Square Inch)
 

Offline Balaur

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Re: Using the ohm symbol in schematics
« Reply #3 on: February 05, 2012, 12:56:28 pm »
And there's the naming scheme where   1R2  = 1.2ohms   or 1k2 = 1.2kohms  etc..
I don't particularly like it, but it's quite common.

The xRy/xKy notation scheme is a live saver when dealing with old schematics scanned from who-knows-where hand-typed or hand-drawn documents.
The decimal dot could be lost very easily.

I absolutely like the Ohm symbol because of the roundness of it, but I didn't yet found a way to use it in this forum. Simple Machines-based forums should be able to support it (and I've tried several ways) but no luck on eevblog.

Cheers,
Dan
« Last Edit: February 05, 2012, 12:58:20 pm by Balaur »
 

Offline caroper

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Re: Using the ohm symbol in schematics
« Reply #4 on: February 05, 2012, 01:17:36 pm »
? - Hold the [Alt Gr] key (or the Alt Key closest to the numeric pad) and type 234 on the numeric pad (Numlock not needed).
as you can see it works here in the forum but I don't use Altium so it is up to you to test.


Cheers
Chris


EDIT: It looked fine in the editor but reverted to a ? when the message saved, very Strange, but still may be worth testing in Altium.

« Last Edit: February 05, 2012, 01:19:09 pm by caroper »
 

Offline wkb

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Re: Using the ohm symbol in schematics
« Reply #5 on: February 05, 2012, 06:16:23 pm »
?
EDIT: It looked fine in the editor but reverted to a ? when the message saved, very Strange, but still may be worth testing in Altium.

Same problem here, I tried entering the ohmega symbol from my Mac.  Could be the forum software.
 

Online IanB

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Re: Using the ohm symbol in schematics
« Reply #6 on: February 05, 2012, 06:26:10 pm »
I've tried entering the ohms symbol here a few times and it always fails. It does seem to be the forum software because it works everywhere else I've used it. Oddly, the degrees symbol seems to work--it's 22°C outside today--but Omega (?) worketh not.
 

Offline jahonen

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Re: Using the ohm symbol in schematics
« Reply #7 on: February 05, 2012, 06:42:48 pm »
Non-working characters might be due to that the database holding these messages does not use unicode character set. One feature of the unicode is that it has separate codes for the ohm sign ? (alt+2126) and big greek omega ? (Alt+03A9). Degree character ° is in 8-bit ISO charsets, so perhaps that's why it is saved, also same for ±.

I think that EDA software authors or development teams are not the most concerned about unicode support in the software :) Although it would be nice to use correct symbols as there is no longer need to settle for 8 bit character set due to lack of support. Windows has used unicode for a quite long time now, and I'm sure that Linux and other similar OS's have similar situation nowadays.

Regards,
Janne
 

alm

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Re: Using the ohm symbol in schematics
« Reply #8 on: February 05, 2012, 07:16:39 pm »
Non-working characters might be due to that the database holding these messages does not use unicode character set. One feature of the unicode is that it has separate codes for the ohm sign ? (alt+2126) and big greek omega ? (Alt+03A9). Degree character ° is in 8-bit ISO charsets, so perhaps that's why it is saved, also same for ±.
Agreed. It's probably converted to ISO 8859-1, which is unable to represent the capital Omega, hence the question mark. This may be a simple oversight in the Simple Machines Forum setup procedure.

I think that EDA software authors or development teams are not the most concerned about unicode support in the software :)
I'm surprised. There's got to be demand for the ability to incorporate Chinese characters in schematics. Using unicode is the only way to support non-Latin languages and keep your sanity.
 

Offline caroper

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Re: Using the ohm symbol in schematics
« Reply #9 on: February 07, 2012, 08:09:15 am »
This is the message BORG resistance is futile.  ;D


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