Duet Wifi at 15V with 12V Fan and Heater?

  • Hello,
    i use a Duet Wifi with actually 12V.
    But this power source is getting old and I should replace it.

    Now I have from another hobby an 15V 350W power adapter.

    It should be possible to use this Power adapter with my actual setup with 12V Fans and heater
    if I change the maximum PWM to 80%.
    That should give me the same effective voltage for the heater and the fans.

    Did somebody try that?


  • It would work fine with heaters, not so sure about the fans as they will still see 15v peaks. It may well work, for a while.

    You'd be better off using a dc/dc converter to drop the voltage for the fans.

    Edit; I might not bother dropping the duty cycle for the heaters if the wiring and connectors can handle it; just re-tune the heaters for the new voltage. You'll get the same warning about over powered heaters anyway, i.e. it won't be any safer, only slower.

  • You will be just fine with the increased voltage and as bearer says, re-tune the heaters. You will however find that you might need to change the duty cycle to 60% as power = current * voltage squared.

  • administrators

    To reduce the fan voltage back to 12V, you could remove the VFAN jumper and replace it with 3 silicon diodes connected in series, between the VIN pin of that jumper block and the centre pin. Keep clear of the 5V pin!

  • Ok, thanks for your answers.
    I will try that 🙂

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