I can't figure this out! Reverse motor direction.

Discussion in 'The Projects Forum' started by amoore67, Mar 26, 2012.

Thread Status:
Not open for further replies.
  1. amoore67

    Thread Starter New Member

    Mar 26, 2012
    3
    0
    :confused:
    I want to design a circuit that uses one momentary push button switch (spdt) to control a dc motor in both directions (it is a 5v dc system).

    1. Hold the momentary push button, the motor turns one direction. Stop holding, motor stops.
    2. Hold the same momentary push button again, the motor turns the opposite direction. Stop holding, motor stops.
    3. Repeat 1...2...1....2...1...2..

    I think this system will require some a flip flop switch of some kind. Maybe two 555s or something but I can't figure it out due to my lack of knowledge on the subject. Most circuits I find are constant but I don't want the motor to be constant I want it to be momentary or the motor turning for the duration the button is pressed. I realize this would be easy if I just used two buttons and an H bridge or if I use a toggle switch but that isn't what I am trying to do here.

    Thanks in advance
     
  2. wayneh

    Expert

    Sep 9, 2010
    12,101
    3,033
    I don't know if it'll help, but I recently worked on a polarity switching circuit using a 4017 counter. The counter output is either hi (source) or lo (sink). So if you compare the "1" output to the "0" output pin, you'll see the polarity reverse as the count advances. You'll want to reset on 1, I think.

    The 4017 cannot likely drive your motor directly, so you'd need to put the output to a power op-amp in comparator configuration to give you enough current.
     
  3. strantor

    AAC Fanatic!

    Oct 3, 2010
    4,302
    1,988
    Google Impulse relay
     
  4. amoore67

    Thread Starter New Member

    Mar 26, 2012
    3
    0
    A counter ic is something I am looking into. I need to figure out a formula that will give me decimal 0,1,0,2,0 and so on
    or binary
    00
    01
    00
    10
    00
    and so on

    As for an impulse relay, from what I have read it only has 2 positions, off and on where I need 3 positions. If wired as an H bridge the motor would always be running but I need it to stop. I want the motor to change with each press of the button for the duration the button being pressed down.
    1. stop, button not engaged
    2. motor turns right for the duration of the button held down
    3. stop, button not engaged
    4. motor turns left for the duration of the button being held down
    5. stop, button not engaged
    and so on
     
  5. strantor

    AAC Fanatic!

    Oct 3, 2010
    4,302
    1,988
    The impulse relay is a latching relay that will change state on powerup, so each time you energize it, it will reverse the direction. it has Normally open contacts and normally closed contacts, just like an ordinary relay.

    Check out this drawing here I did for someone else - he wanted the exact same operation as you describe. He was using an X10 home automation module and wanted that when the module activates it will open a cupboard door, and when it activates again, it will close the door. When the module is not activated, it does nothing.
    [​IMG]
    Replace the X10 module contact with your pushbutton
    Replace the actuator with your motor
    replace 12V with 5V.
     
  6. Wendy

    Moderator

    Mar 24, 2008
    20,765
    2,536
    Her is the problem. In this thread you spelled out this was an automotive problem.

    http://forum.allaboutcircuits.com/showthread.php?t=68010

    You are not going to be able to pursue this on this site. You can take it to the other suggested sites, but not here.

    Please do not open this subject again. The ToS is clear.

     
Loading...
Thread Status:
Not open for further replies.