electrical shooting track

Discussion in 'The Projects Forum' started by micke_gt, May 20, 2015.

  1. micke_gt

    Thread Starter New Member

    May 20, 2015
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    HI,
    Im new to this forum,
    sorry for bad language hope you can get it anyway

    I would like to hear if you have any ideas on how I can control a motor using relays. Automotive relays?
    The function i looking after is:
    I have a platform that goes on a rail, in each side i have a limit,
    in one side i have mounted a 12v dc motor and a Wheel, and in the opposite side a Wheel, i have stretched a wire between those Wheels
    who is attached to the platform,
    i have ha momentary startbutton.
    the limits have COM,NO,NC
    i got a 12v timer.

    If i press the start button i want the platform to start and when it hits the limit in the end it will stop and start a timer who goes for 3-4 seconds and then return, when the platform hits the other limit i want it to stop, until you press the start button again, then let it do the same again

    I attached a Quick drawing if it will help.

    Thanks for ideas/Micke
    ÄLGBANA2-page-001.jpg
     
  2. AnalogKid

    Distinguished Member

    Aug 1, 2013
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    Your question is very clear. Where are you located? What is your electronics background? Do you want to use a microcontroller like a PIC or Arduino, or do you want to use discrete chips like logic gates? This can be done with two 4093 NAND gate devices and two transistors to drive the relays. You will need two SPDT relays that can handle the motor current.

    ak
     
  3. MaxHeadRoom

    Expert

    Jul 18, 2013
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    It should be possible easily without electronics with an off the shelf timer and hard wired relay logic.
    Max.
     
    RodneyB likes this.
  4. micke_gt

    Thread Starter New Member

    May 20, 2015
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    thanks for quick answers
    I'm located in sweden,
    has only a little experience in electronics. I can solder together a circuit board if anyone can say what components I should have and draw up a drawing of the circuit.
    My idea was to keep it as simple as possible, i have wired upp two spdt relays as a polarity switch just to run the motor when i test-drove it.
    i forget to mention that i would like to have a potentiometer to control the speed of the motor if its possible


    but it is more basic to use electronics or do as Maxheadroom suggest whit hard wired relays?
     
  5. AnalogKid

    Distinguished Member

    Aug 1, 2013
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    If I remember Max's past posts correctly, he has a lot of experience in industrial controls. For the one's I've done, I tend to keep my logic in logic chips. Attached is a first-pass at a track controller.

    Note: U2 pin3 is floating on purpose.

    ak
     
  6. MaxHeadRoom

    Expert

    Jul 18, 2013
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    I was thinking of keeping it simple, without the need to construct any custom S.S. logic etc.
    A potentiometer alone is not an ideal way to control a DC motor.
    Depending on what the motor current is, there are PWM controllers on ebay for $5.00.
    You would need a timer, two (Fwd/Rev) relays, two limit switches and the speed control.
    A couple of P.B.'s.
    I can put a circuit together if needed.
    Max.
     
  7. micke_gt

    Thread Starter New Member

    May 20, 2015
    15
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    Okej, the file you attached dosent work for me ? :)

    Thanks/micke
     
  8. micke_gt

    Thread Starter New Member

    May 20, 2015
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    Okej, yes if you can put a circuit together it would be nice :)
    What is P.B,s ? :)
    I can try to get the data sheet of the motor

    Thanks /micke
     
  9. micke_gt

    Thread Starter New Member

    May 20, 2015
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    This is what i found on the motor.
    Its from a sqrewdriver. :)
    image.jpg
     
  10. MaxHeadRoom

    Expert

    Jul 18, 2013
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    P.B.'s = Push buttons.
    Have you actually confirmed that motor will drive you desired load?
    Max.
     
  11. micke_gt

    Thread Starter New Member

    May 20, 2015
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    Ahh okej :)

    Yes, when i tested the track by drive the motor manual it seems to work , i was thinking that a sqrewdriver was build for hard work, do you have any suggest of another motor ?
    I have tought about a motor from a car that runs the windscreen whipers? :)

    /micke
     
  12. MaxHeadRoom

    Expert

    Jul 18, 2013
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    If you intend running off battery power, you need to use the most economical motor you can.
    The largest source of 12vdc motors is autowrecker yards etc.
    Max.
     
  13. micke_gt

    Thread Starter New Member

    May 20, 2015
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    Okej :) but if you have time and want to you can draw up the circuit :)
     
  14. MaxHeadRoom

    Expert

    Jul 18, 2013
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    I just have to finish a project and will do it after.
    Max.
     
    micke_gt likes this.
  15. KMoffett

    AAC Fanatic!

    Dec 19, 2007
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    Here is a circuit that should serve your purpose. Now I would use a microcontroller.

    Ken
    Motor Start-CW-Pause-CCW-Stop.gif
     
  16. micke_gt

    Thread Starter New Member

    May 20, 2015
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    Okej thanks for the drawing. :)

    the file work, it was my phone that dosent work:), is it possible to change the time that the platform stand still in the end position? and if its possible to controll the speed. ? :)
     
  17. KMoffett

    AAC Fanatic!

    Dec 19, 2007
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    It is designed to have an adjustable pause time. If you want to control the speed you will need a PWM speed controller added.

    Ken
     
  18. micke_gt

    Thread Starter New Member

    May 20, 2015
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    okej is it much work to draw in a pwm controller for you ? :)

    /Micke
     
  19. KMoffett

    AAC Fanatic!

    Dec 19, 2007
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    I don't know what the maximum motor current or your minimum and maximum speed will be, so can't really design it.

    Ken
     
  20. gerty

    AAC Fanatic!

    Aug 30, 2007
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    I did something very similar about 6 years ago. The differences are: mine has a cable strung 6 ' in the air between 2 poles about 80' apart.
    The target is attached to a 1/4" wire frame hanging off the cable. It is controlled with a 4 channel wireless remote ( so range officer can move with officer and not get tangled up). It has 2 speeds, speed can be changed at any time during travel. And it have a siren connected to it so range officer can replicate an actual chase with all the noise/confusion. VB-SO-MOVING-TARGET.png VB-SO-MOVINGTARGET-SCH.png VB-SO-TARGET-SCH-2.png [
     
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