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I've found symbols in this explanation for a four way switch but I can't find that symbol in any of the online circuit-drawing tools I've looked at.

The best alternate representation I've come up with is:

enter image description here

This was an interesting exercise and demonstrates that a four-way switch is just a DPDT with its outputs cross-connected. However, it's not as clear as I'd like as part of a larger diagram. Does anyone have a better representation, or know an online tool that has the X symbol from the above explanation available?

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  • \$\begingroup\$ The symbol I've seen was a box with two wires on each side, an X with crossbars connecting the top and bottom, and four dots at the intersections of the X and the crossbars. \$\endgroup\$ – supercat Apr 9 '13 at 23:24
  • \$\begingroup\$ @supercat That's the symbol I've seen as well, but it doesn't seem to be present in the diagramming tools I've tried. \$\endgroup\$ – Brad Mace Apr 9 '13 at 23:26
  • \$\begingroup\$ Related thread. \$\endgroup\$ – Nick Alexeev Apr 9 '13 at 23:30
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4-way switches (DPDTs) have a basic configuration that does not include wires. You choose, as a circuit designer, how you want the wires to connect or inter-connect. You don't see symbols with the cross-linking because nobody makes DPDT switches like that - you have to connect wires to them and then this becomes the symbol of a DPDT with wires on.

Looking at other things - a simple BJT symbol is clear enough but you also get a symbol of two BJTs connected together in Darlington configuration. You can manually connect two transistors together in your schematic OR you can choose the symbol that automatically has the two joined: -

schematic

So why do you get this flexibility with BJTs? Simple reason is that the transistor manufacturers make composite transistors containing two transistors already pre-wired in Darlington therefore there is a symbol.

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  • \$\begingroup\$ Certainly one can buy switches for mains current which have four terminals wired in a "4-way" configuration. I'm not sure how such things are constructed internally--it's possible that they're built as a DPDT and wires, but other arrangements would be possible. For example, one could have a rotary switch with four fixed contacts (north, east, south, and west) and movable contacts which either bridge NE/SW or NW/SE, although the ordering of such contacts around the perimeter would differ from a typical 4-way switch. \$\endgroup\$ – supercat Apr 10 '13 at 19:04
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This page has something similar to what you are describing, but I think not exactly: http://www.eleinmec.com/article.asp?12

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