Using a DPDT to automatically reverse the polarity of motor

Discussion in 'The Projects Forum' started by janej, Aug 20, 2010.

  1. janej

    janej Thread Starter New Member

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    I am currently working on a project that requires a motor to run this way and then hit a switch that would enable it to reverse its polarity. However, I have to wait for a signal from an LDR and this signal is what would drive the motor the other way.

    Is there an automatic DPDT switch that I could use?

    Thanks!
     
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  2. marshallf3

    marshallf3 Well-Known Member

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    "All in one" I seriously doubt, easy to build with minimal components - yes.

    Voltage & current requirements of the motor?
     
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  3. mcgyvr

    mcgyvr Senior Member

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    #3
  4. SgtWookie

    SgtWookie Expert

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    This is a circuit I whipped up awhile back for a fellow who used it in a model of a German WWII Tiger Tank:

    [​IMG]

    It could probably be modified to suit your needs, but you'll need to give more specifics about your LDR and it's resistance when illuminated and dark.

    The diagram shows two relays. The actual relay used was a dual form C H-bridge relay, NEC EP2 series. These are available from Mouser.com
    You don't have to use an H-bridge relay though; a pair of SPDT relays could be used.
     
    Last edited: Aug 20, 2010
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  5. soda

    soda Active Member

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    I add a pic of how you can use a DPDT switch to reverse the motor direction. I use it all the time with no problems
     
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  6. williamj

    williamj Active Member

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    janej,

    We need to know more about the motor, is it AC or DC, if AC... is it single phase or three phase. For a good circuit, accurate motor information is paramount.

    williamj
     
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