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switching circuit

Discussion in 'Electronic Projects Design/Ideas/Reviews' started by Raymond Llewellyn, Nov 5, 2017.

  1. Raymond Llewellyn

    Raymond Llewellyn New Member

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    im trying to come up with ideas to operate an electric switch for my model railroad that is not expensive because i will need to do this 17 times was thinking of maybe an ir circuit to a jk flip flop i would like it to switch and then back with out having to do it manually. any ideas will help i have an AS in electronics and would really like to make this layout work with as much electronics as i could possibly do thanks you
    all
     
  2. alec_t

    alec_t Well-Known Member Most Helpful Member

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    Welcome to ETO!
    What voltage and current will it have to switch, and how often?
    What power supply do you have available for the circuit?
    What delay before it switches back?
    What will you use for the IR remote?
     
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  3. Raymond Llewellyn

    Raymond Llewellyn New Member

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    it will be 5 v dc up to 12 vdc this is going to be on a model railroad would like it to be activated by the actual train an switched back after train passes
     
  4. dave

    Dave New Member

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  5. Raymond Llewellyn

    Raymond Llewellyn New Member

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    was leaning towards an IR circuit but never got the opportunity to work with them before an not sure of the cost let alone the difficulty of building a reliable circuit for it
     
  6. eTech

    eTech Active Member

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    Hi

    Will there be multiple trains operating at the same time?
    If so, and you want the train to "auto-throw" the electric switches, then the meet/pass logic to keep the trains from colliding can get very complicated.
    What type of electric turnouts? Polarity sensitive? Dual coil? Pulse operated?
     
  7. Raymond Llewellyn

    Raymond Llewellyn New Member

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    yes there will be multiple trains but not at the same time as for now maybe at a later date im trying to figure out what would be a good working circuit that can be tripped by the train im not set in stone as what to do to make it work . this is my first layout and im investigating on what to do i havent bought the turn outs yet. this is mostly in design mode and just really looking for ideas
     
  8. alec_t

    alec_t Well-Known Member Most Helpful Member

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    Something like this perhaps for the IR sensor?
     
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  9. jpanhalt

    jpanhalt Well-Known Member Most Helpful Member

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    IR is a good option and will detect all trains. However, if you want some trains to throw the switch and others not to, you can use a Hall sensor and a magnet on the trains that throw the switch. Hall sensors are used the the ABS system of cars.

    John
     
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  10. Raymond Llewellyn

    Raymond Llewellyn New Member

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    thank you all im going to try building some circuits and see what will be the best option i am also investigating on using photo sensors and either d latches or jk latch thanks for any and all ideas if something else comes to mind like i said any and all ideas welcome
     
  11. dougy83

    dougy83 Well-Known Member

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    An option is a magnet on the train, and a reed switch on the track for the sensor. The switch on, then back off function can be done using a few schmitt-trigger gates, some timing resistors and capacitors and two relays (assuming you're doing track changes with pulsed solenoids)
     
  12. Colin

    Colin Member

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    You can see IR sensors and crossing sound and lights and boom gates project on talking electronics.com website
     
  13. jpanhalt

    jpanhalt Well-Known Member Most Helpful Member

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    IR is a type of photosensor. The technology for packaged IR sensors is well developed. You can even have codes for each train and in theory have a train throw a switch or not depending your control signal -- just like you can select which channel to watch on TV.
     
  14. jpanhalt

    jpanhalt Well-Known Member Most Helpful Member

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    Regarding Hall sensors, they work very much like a mechanical switch, except the switching element is a transistor. You can get versions that give an analog output proportional to the magnetic field or versions that simply switch when the field is equal to or greater than a threshold.

    You probably want the latter type. They are used in all sort of counting and timing circuits.
     
  15. Colin

    Colin Member

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    You can't "think up a name" and use it in a circuit.
    Using jk things is like going back to the ark and they are very hard to use. If they were easy, I would have used them in the past 50 years.
    Your whole thing revolves around delays and this requires lots of little things with coloured bands on them (I can't remember the name) and it is much easier to go to a micro where all the little bits and pieces are inside the 8 pin chip and you just stick it into a socket and the thing works.
    You have to use 38kHz detection otherwise fluoros and lighting will muck up the detection.
     

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