Forward reverse control for sliding gate

Discussion in 'The Projects Forum' started by RodneyB, Nov 29, 2015.

  1. RodneyB

    Thread Starter Active Member

    Apr 28, 2012
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    Hi

    I am looking for a basic circuit diagram for a forward and reverse control for a sliding gate.

    The motor load will be switched through 2 relays. The activation will be controlled by a pulse. The supply voltage is 12 Volts and the motor is an old windscreen wiper motor.

    Basically when the button is pressed I want the gate to open or close, when it gets to the end limit it stops and waits for another pulse to run in the opposite direction.

    Many thanks

    Rod
     
  2. Dodgydave

    AAC Fanatic!

    Jun 22, 2012
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    If you remove the mechanism and allow the motor to run freely, you can reverse its supply and it should run in reverse, if thats the case a simple dpdt relay and limit switches can be used to reverse it.


    http://i.imgur.com/FKJlfzX.png
     
  3. RodneyB

    Thread Starter Active Member

    Apr 28, 2012
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    Thank you very much for your reply. This makes perfect sense. I have proximity switches can I use these? Also how would I start the motor
     
  4. Dodgydave

    AAC Fanatic!

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    You need a normal open switch and a flipflop using a 555 timer can be used,

    best to use microswitches for the limits,
     
    Last edited: Nov 29, 2015
  5. djsfantasi

    AAC Fanatic!

    Apr 11, 2010
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    You want to start in either direction with a pulse, correct? One pulse, it opens; the second pulse it closes?

    The circuit shown works by switching power to the control inputs. To control with pulses will require additional circuitry.

    A T flip flop is suggested. The T input is your pulse and the Q output connects to a transistor driving the relay. You'll need a diode if you use logic chips; a T flip flop can be made with relays, too. image.png
     
    RodneyB likes this.
  6. RodneyB

    Thread Starter Active Member

    Apr 28, 2012
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    Thanks very much
     
  7. RodneyB

    Thread Starter Active Member

    Apr 28, 2012
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    With the T flip flop, is Q one direction and /Q the other. Will I need a clock pulse?
     
  8. Dodgydave

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    Jun 22, 2012
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  9. AnalogKid

    Distinguished Member

    Aug 1, 2013
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    If you don't want to solder chips and things, you can do this with a toggle or impulse relay and either one or two motor power relays. With one DPDT power relay, it will be on all the time in one end state and off all the time in the other end state. With two SPDT power relays, all relays are off at either end state. If your input signal can drive a relay coil, using an impulse relay for the toggle function is very simple but relatively expensive, around $30. For much less money but more work you can use a 555 or grow a toggle ff with gates, and use it plus power transistors to drive either one or two relays as above.

    ak
     
  10. djsfantasi

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    DodgyDave is right. The clock pulse is a pulse from your input, whatever you have.
     
  11. RodneyB

    Thread Starter Active Member

    Apr 28, 2012
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    Thanks for the help let me do a drawing of the circuit and then see from there. is the CD4013 a suitable IC to use.
     
  12. MaxHeadRoom

    Expert

    Jul 18, 2013
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    The advantage of the magnetic latching relay is it has memory, retains the status in no-power condition.
    Max.
     
  13. djsfantasi

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    The CD4013 is a suitable IC
     
  14. AnalogKid

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    This is from a previous thread. Change to 12 V, and replace the sensor relay with an impulse relay. All relays can be had with 12 V coils. Also, be wary of "normal" power relays - they have huge AC current ratings, but many are not suited to switch DC. Little automotive critters like the Siemens (P&B) T90 series are excellent.

    ak
    MotorReverseSensor-1-c.gif
     
  15. RodneyB

    Thread Starter Active Member

    Apr 28, 2012
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    Thank you very much
     
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