pwm voltage

  • Hi guys
    I would add a device to heat my 3d printer chamber and the device seller ask me if i have 10 to 24 volts pwm output signal from my duet2 board to pilot this device.

    Could any body tell me please the voltage that i have in the pwm output?

    If i have 3.3v or 5v in the pwm output signal, is possible to pilot a SSR with my pwm signal and conect 24volt in the open contact of the SSR?

  • As far as i understand, pwm pulse amplitude is VIN on heater pins, also on fan pins, unless you selected with jumper to use 5 v, and 5v on servo pin(s). So in short, yes, you have 10 to 24 v pwm signal.

  • Voltage for every connector is noted in the key on the wiring diagram.

  • thanks guys for your reply

  • i found a device to heat the air pushed inside of my chamber by a fan , the problem that i actually have is that at the maximun power of the heater, the output air can reach more than 300°C and it can be obviously a big problem for the components that i have inside of my machine and for the safety.

    if i'm not wrong i can limitate the power of the heater making the maximun pwm output signal in a percentage like 20% when is at maximun output right?

    So if the output signal at 100% mean 300°c, Can I setting that output parameter when the heater at maximun power will be just the 20% (80°C) to avoid in any case a 300°c temperature in the air output?

    Thanks for your help

  • administrators

    Yes and no. Yes, when everything is working correctly. No if there is a failure of the electronics or firmware or your configuration files and 100% PWM gets applied by mistake. So if 100% PWM would risk a fire or cause severe economic damage, then you shouldn't rely on restricting the PWM to limit the temperature rise unless you also use a thermal cutout.

    What type of heater is it? If it's a DC heater, you could reduce the voltage to reduce the heater power. If it's an AC heater, you may be able to halve the power by connecting a diode in series with it.

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