fans with shared positive



  • I have 2 part fans connected together and 1 thermally controlled tool fan, they are all 12v connected to the duex5. I'm in a corexy setup and thinking of reducing the number of wires that go from the head to the duetwifi/duex5.

    It is my understanding that the positive lead is shared with all fans. My idea was to use just 1 pos and 2 negs. On the duet side I'm connecting the 2 part fans together to one header (+ and -) and the tool fan to another header (just the negative since the positive is shared on the other header). Does it make sense? Does that impact on the total max amperage? Just wanted to check this config with you before burning my duet 🙂 Thanks!

    PS: I wanted to add that both this forum and the wiki are an incredible source of knowledge, I was able to go from zero to full functioning corexy by just RTFM 🙂 so thanks guys!


  • administrators

    @matt3o said in fans with shared positive:

    It is my understanding that the positive lead is shared with all fans. My idea was to use just 1 pos and 2 negs. On the duet side I'm connecting the 2 part fans together to one header (+ and -) and the tool fan to another header (just the negative since the positive is shared on the other header). Does it make sense? Does that impact on the total max amperage? Just wanted to check this config with you before burning my duet

    Yes you can do that. I recommend limiting the maximum current to 2A per pin. So in your case, the total current draw for the 3 fans should not exceed 2A while they are running continuously.



  • thank you for your super fast reply @dc42 . I finally replaced all the spaghetti wiring with a nice and tidy cat6 cable and everything works as expected. All the fans together drain 0.2A at full speed, so that shouldn't be a problem!


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