Using multiple outputs for single heater



  • I would like to have possibility to use multiple outputs for a single heater. This would allow to split the load between 2 (or more) outputs.

    It a little waste having 2 outputs capable of 6A unused (Duet3) and mount mosfet to drive 2x5A heater element for chamber.

    It is possible to create two chamber heaters but PID tuning is a nightmare.


  • administrators

    If you create 2 chamber heaters with exactly the same M307 parameters and using the same sensor, then I think they should work Ok together. PID tune them individually, then construct a M307 command using the sum of the gains and the average of the cooling rates and dead times.

    I will look into supporting dual heater outputs.



  • I asked about that some time, and tried this approach. But was not able to get stable PID values.
    Also this feature seems to be fairly easy to implement, but I did not look into the code.

    I can not wait to test 3.2 beta 🙂



  • I have a similar situation where this would be very useful in general for heater outputs for multi-heater beds and extruders and other things.


  • administrators

    I have added this to the firmware work list. For Duet 3 there will be a restriction that both outputs must be on the same main or expansion board.


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