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).

enter image description here

Update: Picture added.

  • 1
    \$\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
  • 3
    \$\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 Sunnyskyguy 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 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.

| improve this answer | |
  • \$\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

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.