I'm wondering if there is anyone out there with a definitive answer to why and/or what standard would call out the usage of the different voltage sources. There are Bars, Arrows, Dots, Waves, etc. I have in the past defined this, but I'm wondering if there are actual standards that also define it.

What I've used in the past is:

  • Wave: AC power source
  • Bar: DC Power Source (regulated)
  • Circle: DC Power source (unregulated)
  • Arrow: no idea...

If anyone has any reference to something more concrete, I would love to hear it (and bonus if there's actually reasoning to why we have so many available).

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Update: Picture added.

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    \$\begingroup\$ Can you provide any pictures of what you're talking about? IEEE Std 91/91a, IEC 60617, and ANSI Y32.2-1975 all have their methods of keeping consistent symbol usage. \$\endgroup\$ – user103380 Jun 6 '19 at 16:30
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    \$\begingroup\$ This is why there are so many standards: xkcd.com/927 \$\endgroup\$ – Voltage Spike Jun 6 '19 at 16:48
  • \$\begingroup\$ Or this std. imgs.xkcd.com/comics/circuit_diagram.png. Arrow in circle is a current source \$\endgroup\$ – Tony Stewart EE75 Jun 6 '19 at 16:59
  • \$\begingroup\$ This is where trust issues arises from, tons of standards, if I were you I would just use either of them and then write in plain text nearby what it is. - At my university I had one teacher who preferred the bar one, another teacher who preferred the arrow, both of the teachers were talking about the exact same kind of voltage source. \$\endgroup\$ – Harry Svensson Jun 7 '19 at 17:41
  • \$\begingroup\$ It doesn't matter because nobody who reads the schematics is aware of the standards anyway (if any). I have not actually seen the wavy line before. But the circle triangle and horizontal line (or I guess you could call it a 'T') are all familiar. \$\endgroup\$ – mkeith Apr 26 '20 at 19:13

You might want to have a look at IEEE Std 315, "Graphic Symbols for Electrical and Electronics Diagrams". Of course, this is a U.S. standard and other countries may have their own standards.

  • \$\begingroup\$ That standard only calls out common nets (i.e. 0 Volts potential). I'm looking for DC power nets specifically... \$\endgroup\$ – Patrick Cox Jun 7 '19 at 17:18
  • \$\begingroup\$ No, a "common net" does not mean "0 volts potential". It is any net that has a number of common connections but you don't want to draw the actual wire. \$\endgroup\$ – Elliot Alderson Dec 25 '20 at 14:06

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