Standby power from +5V in

  • I see that there is a connector on the Duet WiFi that has three pins: 5V in, PS_ON, and GND. This appears to be for controlling an ATX power supply; indeed, the PS_ON pin correctly switches the ATX supply on and off. I connected the 5V in pin to my PSU's 5V standby wire, but it does not power the Duet. I think that to make that happen I need to switch a jumper. I want to check, though, since I quite like the Duet and would rather not see the magic smoke come out.

    Should I switch the jumper from 5v internal to 5v external?

    Once I've done that, is it safe to connect the Duet to a USB port? Will it still run off USB alone?


  • I have connected the +5V, PS_ON and GND to my ATX PSU (and moved the jumer to the external 5 V). I can now use M80 and M81 to turn the 12 V supply on and off.

    With the ATX PSU turned off I can connect USB and power the board as normal (with no 12 V).

  • administrators

    Hi Anne

    There are diodes in place to prevent feeding USB power into your 5v supply, or more likely your 5V supply back feeding the USB supply.

    No issues switching to external 5v an connection via USB when required. The header is designed to switch a standard ATX power supply.on and off, running the Duet off the standby 5V

  • Thanks, I've now set up my printer that way and it seems quite content. I put a note about this on the "power wiring" page of the wiki.

  • administrators


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