Motor control problem in line follower robot.. Please help

Discussion in 'The Projects Forum' started by sunatraye, Apr 12, 2012.

  1. sunatraye

    Thread Starter New Member

    Apr 12, 2012
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    Hello everyone,
    I am making a line follower robot for my varsity project show. But the problem is every time the motor starts voltage from power supply drops significantly.
    I think this happens because of motor noise. but i cant control it. what should i do? Should i use capacitors? If so what value should i use?

    I must mention, i am using Pic18452 micro controller and L293d motor driver for my two motors.

    Please help me. I am near my deadline.
     
  2. bertus

    Administrator

    Apr 5, 2008
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  3. sunatraye

    Thread Starter New Member

    Apr 12, 2012
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    Thank you for your reply Bertus. But i am using only two 12 volt dc motor. I knew L293d can run this type of small motors. If not what else should I use?
     
  4. bertus

    Administrator

    Apr 5, 2008
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    Hello,

    Can you post a current schematic?
    Do you also have the specs of the motor to use?

    Bertus
     
  5. sunatraye

    Thread Starter New Member

    Apr 12, 2012
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    Here is my schematic on proteus7.7 I do not understand what you meant by the specs of the motor to use.
     
  6. JBSPINZ

    New Member

    Apr 12, 2012
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    what type of filter are being used in the power supply ?



     
  7. bertus

    Administrator

    Apr 5, 2008
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    Hello,

    I can not open the proteus file.
    Can you post a screenshot in .png format?

    Bertus
     
  8. sunatraye

    Thread Starter New Member

    Apr 12, 2012
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    I have sent the screen shot.
     
  9. bertus

    Administrator

    Apr 5, 2008
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    Hello,

    What is powering the MCU?
    What is the input voltage of the 7812?
    Are there capacitors mounted on the input and output of the 7812?
    You should use a 0.33 μF at the input and 0.1 μF at the output of the 7812, to avoid oscillating of the 7812.

    Bertus
     
  10. MrChips

    Moderator

    Oct 2, 2009
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    Simple solution. Power the MCU from a separate battery, not on the same battery that is supplying the motor.
     
  11. sunatraye

    Thread Starter New Member

    Apr 12, 2012
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    I have tried that already but didn't work.
     
  12. sunatraye

    Thread Starter New Member

    Apr 12, 2012
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    At first I used a 24v adapter. 7805 and 7812 was connected in parallel for MCU and motor respectively. After having problem i tried separate 12v batteries but that didnt work too.
     
  13. sunatraye

    Thread Starter New Member

    Apr 12, 2012
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    I haven't used any filter yet. What should i use as filter and where?
     
  14. marufuddin0

    New Member

    Feb 24, 2016
    1
    0
    Though the problem was posted a long time ago, the problem was occurred same to me. I have solved this problem using gear. It will reduce rpm but increase torque. So, at loaded condition it may move too.
     
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