Heating pad power help

Discussion in 'General Electronics Chat' started by dociledragons, Oct 6, 2013.

  1. dociledragons

    Thread Starter New Member

    Oct 6, 2013
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    First I'm posting this b/c my situation has changed. I fried the original circuit board so now I just want to power the heating pad safely.

    Is it as simple as connection a switch and resister straight to the heating element or would that burn up the element. Actually, It's the heat wiring if that makes a difference.

    The unit says 60Hz/ 49Watts/ 120V if that info is needed
     
  2. #12

    Expert

    Nov 30, 2010
    16,261
    6,770
    Typically, heating pad controls are junk. I have 2 that read the same for off and low, then read the same for medium and high. I just shorted out the switch and built a box with a $10 light dimmer, a timer, and a duplex receptical where I plug in an LED night light and the heating pad. Set the dimmer to 3 out of 10 for 35 minutes and I'm properly cooked.
     
  3. dociledragons

    Thread Starter New Member

    Oct 6, 2013
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    0
    Yes, but I'm looking for a simply schamatic for under a couple buck to reduce the watts by 50-60 percent.
     
  4. #12

    Expert

    Nov 30, 2010
    16,261
    6,770
    I should have saved the drawing for the half power soldering iron.
    Just stick a diode in series with the heating pad. 1N4007 should work.
     
  5. ScottWang

    Moderator

    Aug 23, 2012
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    Try the AC dimmer control by Triac.

    The circuit is easy, you can diy or buy the product from local store, I was built it for the fan speed control, the Iron temperature adjust, and I also bought it from the store, it cost about $US3.333.
     
  6. dociledragons

    Thread Starter New Member

    Oct 6, 2013
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    Will this work with 110V?
     
  7. ScottWang

    Moderator

    Aug 23, 2012
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    It's ok for AC110V or AC120V, here in Taiwan is AC110V, I think your heat pad only 49W, so you only need the TRIAC BT136.

    Here has some circuits but it's Chinese version, I think it's ok , because you just need to see the circuit, that is suitable for AC110V.
     
    Last edited: Oct 20, 2013
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  8. dociledragons

    Thread Starter New Member

    Oct 6, 2013
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    Thanks for the info. Should I use the first or second diagram?
     
  9. ScottWang

    Moderator

    Aug 23, 2012
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    The first circuit in this file, and using BT136 or similar type.
     
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