sliding door

Discussion in 'General Electronics Chat' started by Kaiser Ed Bayawa, Feb 7, 2016.

  1. Kaiser Ed Bayawa

    Thread Starter Member

    Mar 19, 2015
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    hi.. I am making a simple automatic sliding door with an LDR sensor and a triac to drive the motor.
    the problem is when the door is open i dont have an idea to close it. what will i do to reverse the polarity of the motor?
     
  2. ISB123

    Well-Known Member

    May 21, 2014
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    You need H bridge.
     
  3. bertus

    Administrator

    Apr 5, 2008
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    Hello,

    What kind of motor do you use?
    Also keep in mind that you block the movement of the door when there is something in the doorway.

    Bertus
     
  4. Kaiser Ed Bayawa

    Thread Starter Member

    Mar 19, 2015
    61
    6
    What is an h bridge sir
     
  5. Kaiser Ed Bayawa

    Thread Starter Member

    Mar 19, 2015
    61
    6
    I am using a servo motor
     
  6. djsfantasi

    AAC Fanatic!

    Apr 11, 2010
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    How are you driving the servo motor to open the door? Servos operate differently than DC motors.
     
  7. ISB123

    Well-Known Member

    May 21, 2014
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  8. djsfantasi

    AAC Fanatic!

    Apr 11, 2010
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    But not a servo.
     
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  9. Kaiser Ed Bayawa

    Thread Starter Member

    Mar 19, 2015
    61
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    I have also here a dc motor sir. Which on I will use
     
  10. ISB123

    Well-Known Member

    May 21, 2014
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    Didn't see he was using a servo. Servo is driven with PWM, NE555 can be used.
     
  11. Kaiser Ed Bayawa

    Thread Starter Member

    Mar 19, 2015
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    Thank you for the help sir. I will do a research about this h bridge and how to use it.
     
  12. MaxHeadRoom

    Expert

    Jul 18, 2013
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    You can also drive a servo motor with plain DC which is reversed by contactor or relay.
    PWM is if you require rpm control.
    This is assuming it is not a simple RC servo but an industrial one?
    Max.
     
  13. twohats

    New Member

    Oct 28, 2015
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  14. MaxHeadRoom

    Expert

    Jul 18, 2013
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    It sounds like you are powering it already to open it, you just need reversal?
    It is wise to qualify in your OP whether it is a model RC servo type or other.
    Max.
     
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  15. Kaiser Ed Bayawa

    Thread Starter Member

    Mar 19, 2015
    61
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    Can I combine this scr circuit with the h bridge sir ? instead of using the lamp in the scr I will change it with the h bridge together with the motor
     
  16. Kaiser Ed Bayawa

    Thread Starter Member

    Mar 19, 2015
    61
    6
    Is it possible to combine the two circuit sir and how?
     
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