Understanding the PS_ON pin and header



  • As I understand it:
    The PS_ON header has three wires. 5V, GND and Signal (PS_ON). The GND pin is connected to the GND rail of the Duet board. The 5V pin is an INPUT meant to accept 5v-20v from an external source. The PS_ON pin is controlled via M80 and M81 commands. When activated by an M80 command this pin will be connected to the 5V input pin next to it.

    Is this correct?

    Please forgive me for asking a question which should be easily testable and not require a forum post. I suspect I might have burned up this circuit, so I am trying to verify how it is supposed to work.



  • @punamenon said in Understanding the PS_ON pin and header:

    When activated by an M80 command this pin will be connected to the 5V input pin next to it.

    No the PS_ON pin will be pulled to ground when M80 is run, to allow it to turn on an ATX style power supply where you would connect the green "power on" line (pin 14) to ground to turn on the power supply.

    The 5v input is then connected to the 5V stand by output of the power supply so the Duet can run from that.

    You also need to move the 5v_int jumper to 5v_ext to use external 5v.



  • @bearer Thank you!


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