I recently found out about Nixie tubes, how to implement the decoder, microcontroller, as well as the power management.

I have one big problem. I don't really know if ground = ground.

On the schematic it is shown that all grounds are connected to one another (ground terminal) as if I could just draw a line and connect them, but I'm not quite sure if I understand that correctly.

enter image description here

Image and Schematics are by GreatScott

  • \$\begingroup\$ why are you not questioning the +5V also? \$\endgroup\$
    – jsotola
    Commented Feb 7, 2021 at 4:14

2 Answers 2


That's standard terminology (he, he!) in schematics. All nodes with the same symbol are connected together. Just like everywhere that says "A2" means that the points are all connected, using the same ground symbol all over the place means that those grounds are connected together.

This convention allows for neater diagrams - you don't have ground wires running all over the schematic.

Sometimes you will see schematics that use different ground symbols. There might be the one with bars like your schematic has, and ones like triangles. Those are separate grounds. In that case, only the grounds with the same symbols are connected together.

  • 1
    \$\begingroup\$ And if the two ground symbols are shown linked together explicitly, that indicates you probably have a split ground, with two ground planes only connected through one or two carefully-positioned traces. \$\endgroup\$
    – Hearth
    Commented Feb 6, 2021 at 18:35
  • \$\begingroup\$ Well, if there's some with bars and some with triangles then either you're supposed to keep them separate, or someone was lazy and/or stupid, or you're working in a company that has some well-established conventions that no one has told you about. If you mix signals like that and don't indicate something on the schematic (like the connected symbols that @Hearth mentions), then there should be some textual annotations explaining what's up. \$\endgroup\$
    – TimWescott
    Commented Feb 6, 2021 at 19:10

You interpretation is correct, in this case GND = GND and also includes the ground symbol. If the grounds were separate for some reason, there would be a different name.

Lines could be drawn between these points but they are often left out for ease of readability.


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