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Unresolved AC Heated Bed

Discussion in 'Troubleshooting' started by regor, Mar 7, 2016.

  1. regor

    regor Member

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    Want to try a 600W ac silicon pad with a SSR relay for switching from ramps 1.4 board using original glass bed. Do I have to modify the firmware at all? Thermistor is valued at 100k ohms.
     
    #1 regor, Mar 7, 2016
  2. mark tomlinson

    mark tomlinson ༼ つ ◕_ ◕ ༽つ
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    #2 mark tomlinson, Mar 7, 2016
  3. regor

    regor Member

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    #3 regor, Mar 7, 2016
  4. regor

    regor Member

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    I noticed the post you referred me to had a DC to DC SSR due to his heater being DC. Mine is a AC heater and DC to AC SSR.
    Is this bang-bang update still applicable in the firmware?
     
    #4 regor, Mar 7, 2016
  5. WheresWaldo

    WheresWaldo Volunteer ( ͠° ͟ʖ ͡°)
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    600W is way overkill, I went with a 300W and it heats up as fast as the 40W hotend. The more wattage the more switching the SSR will have to do to not over/undershoot the temps. Second thing is you will need a bunch of info on the specific thermistor used or supply your own. That is what I am going through right now. The Thermistor that was supplied reads about 30-50% too low with the specified table, so when the Robo reported a bed temp of 60°C it was actually measuring approximately 92°C. Most silicone heaters are only rated to about 200°C maximum, you can't get any hotter (if you can even get that hot), the one I have taps out right around 160°C when it slows temperature gains to a crawl. So all you buy is speed and that is not always a good thing.

    You will still need to use Bang-Bang!
     
    #5 WheresWaldo, Mar 7, 2016
    Geof and mark tomlinson like this.

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