Newbie help with reverse polarity and pushbottons controlling a motor

Discussion in 'General Electronics Chat' started by bmor, Apr 12, 2007.

  1. bmor

    Thread Starter New Member

    Apr 12, 2007
    2
    0
    ok maybe just looking for anykind of help im stuck and i need to use something like this for a project. here is what i want to do.

    ::

    i have a push button ( not one that stays clicked down) ie. one that will be pushed and released. so. when this button is pressed it will cause the motor to turn and when it is released instead of stopping it will reverse and stop. ie.




    [​IMG]
     
  2. hgmjr

    Moderator

    Jan 28, 2005
    9,030
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    So you have what is referred to as a momentary switch.
    Not exactly sure what you mean by "instead of stopping it will reverse and stop."

    Can you clarify this a bit? It almost sounds as though you are describing some sort of braking action that involves a short motor reversal to stop the motor more quickly.

    hgmjr
     
  3. thingmaker3

    Retired Moderator

    May 16, 2005
    5,072
    6
    I think he wants to use a momentary switch to change the angular position of something. When pressed, angular position is A. When released, angular position is B.

    Is this correct? (Or am I barking up yet another empty tree?)
     
  4. bmor

    Thread Starter New Member

    Apr 12, 2007
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    when pressed it would go to position 2 and then when released it would got back to position 1
     
  5. hgmjr

    Moderator

    Jan 28, 2005
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    Aaaahhh! That makes sense.

    I think this can be accomplished with simple mechanical limit switches. Is that what you had in mind or are you looking for something that involves electronic components? (i.e. mosfets, transistors, etc.)

    hgmjr (1500)
     
  6. thingmaker3

    Retired Moderator

    May 16, 2005
    5,072
    6
    You'll need some kind of sensor to detect "position 1" and another to detect "position 2." You'll need a thing called an "H-Bridge." (Use the search function to learn more about this.) You'll need some "logic" to control the H-Bridge based on input from your two sensors and your switch. http://www.allaboutcircuits.com/vol_4/index.html is an excellent introduction to digital electronics and logic circuits.
     
  7. mrmeval

    Distinguished Member

    Jun 30, 2006
    833
    2
    Limit switch 1 is at position 1 and cuts power from switch.

    Limit switch 2 is at position 2 and cuts power from switch

    When switch is not being used the contacts will supply power to turn the motor in the direction to position 1 but limit switch 1 will kill power when it gets there.

    When the switch is pressed power is removed from postion 1 and sent to position 2 which will turn on power in the direction to position 2 but limit switch 2 will kill power when it gets there.

    It requires a more complex switch than simple on and off but it's doable. Limit switches 1 and 2 are simple normally closed switches. I leave it to you to figure out what switch to use as the 'push button' switch. It's a bit more complex than the limit switches but not by much.
     
  8. dodie1002

    New Member

    Jan 29, 2009
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    i think you need to built a circuit thats toggle one relay on and off using one switch using a flip flop ic once the button is press it trigger the relay on and power the motor forwad and when it touch the switch again it will turn off the relay and reverse the motor
     
  9. SgtWookie

    Expert

    Jul 17, 2007
    22,182
    1,728
    See the attached schematic for one possible solution.

    S1 is a NO (normally open) switch. S2, S3 are NC (normally closed).
     
  10. kubeek

    AAC Fanatic!

    Sep 20, 2005
    4,670
    804
    A little late... something like two years :)
     
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