Pull downs for heaters?



  • While being open to overlooking something very obvious wouldn't pull downs on the heaters gate be a safer design if the mosfet driver fails in strange and wonderfull ways?

    I notice that Fan0 and Fan2 does have pull downs, which I guess makes sense as we'd want Fan1 that is normally the hotend fan to run at power on before the firmware takes control; but would we also not want the opposite for all heaters?

    Just had an interesting experience testing if the pwm pins from the microcontroller was working after removing a failed mosfet driver. stuff got nice and toasty. Running the board with no mosfet driver clearly isn't a normal situation, but I would think similar behavior could be triggered by a faulty driver?


  • administrators

    The only times I have seen the mosfet driver chip fail, they failed short circuit. I have never seen a mosfet driver chip fail with an open circuit output.


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