fast timer, fast horses

Discussion in 'The Projects Forum' started by barrelracerdad, Jul 27, 2010.

  1. barrelracerdad

    Thread Starter Member

    Jan 29, 2010
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    Hey guys, I'm back again with another small hitch in my timer curcuit. (See thread "Fast Horses") First of all, thank you for all your help, this thing works great, but I am getting a curcuit trip from the tails of some horses breaking the beam and stopping the timer. What I need is a simple curcuit to make the timer ignore a second signal within a certain amount of time (like a contact debounce switch only for a longer period of time. I would like to ignore any signal within 1 second of the first signal. Is there a simple curcuit to accomplish this?:confused:
     
  2. BMorse

    Senior Member

    Sep 26, 2009
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    You maybe able to just add a capacitor + resistor to the input of the timer, basically to create a "de-bounce" circuit that could last up to a second... are you still using the same circuits in the previous thread??

    B. Morse
     
  3. barrelracerdad

    Thread Starter Member

    Jan 29, 2010
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    Yes, still using same curcuits, works too good to change. Would adding a resistor and capacitor change the first input signal? The timer works very well as it is and is super accurate. If I could just make it ignore that second signal (When it happens we get a signal of about .018-.025) that when the tail breaks the beam and stops the timer. I would like to build it into my timer box inline. Any good ideas?
     
  4. tom66

    Senior Member

    May 9, 2009
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  5. barrelracerdad

    Thread Starter Member

    Jan 29, 2010
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  6. tom66

    Senior Member

    May 9, 2009
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    Well, that's quite expensive ($100 estimated, I read), though it does offer wireless. Is being wireless a requirement? If not, then a simple monostable will be good enough, like one of these:

    http://falstad.com/circuit/e-555monostable.html
     
  7. barrelracerdad

    Thread Starter Member

    Jan 29, 2010
    92
    0
    Hi, I didn't mean the whole wireless part, I just meant the delay capacitor and resistor. It is very similar to what BMorse conjured up, I just need a wiring diagram to build a small board from. I think this could work well for what I need for a couple of bucks in parts. (by the way, the wireless portions could use cast off garage door openers and reciever boards, I have several laying around.)
     
  8. tom66

    Senior Member

    May 9, 2009
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    I'm not certain on your exact requirements, but here is a circuit which will add an element of delay to a short pulsing signal. You may have to adjust the resistors and capacitors to get the right delay, but it should work.
     
  9. BMorse

    Senior Member

    Sep 26, 2009
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    TOM66: Here is the circuit he has right now that he wants to add the delay to....[​IMG]


    and this circuit is attached to this Module from Kitsrus

    http://www.kitsrus.com/pdf/k148t2.pdf

    So whatever delay circuit is implemented here, it has to work with the open collector output of the trigger module and also work with the input to the counter modules, whos input is pulled high VIA resistor on the module...

    The timer module uses a Low going pulse to start/Pause the timer, so the input to the timer has to be high, until the laser beam is blocked, which at that point the trigger pulses the timer modules input low and back to high to get the timer started, now barrelracerdad needs to delay this input by atleast a second, which makes it difficult since the pulse that starts the timer can not be held low for that second, since it will not start timing until that input goes back high....

    So the original circuit should work the way it is now, except after the first input, there should be a delay after that, and only after the first input (when the timer starts), which makes the task difficult, since delaying a second trigger input is what is required here, just putting a delay circuit in between the 2 circuits now, will delay all inputs to the timer regardless if it is the first, second or third trigger input.....

    B. Morse
     
    Last edited: Aug 7, 2010
  10. BMorse

    Senior Member

    Sep 26, 2009
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    OK, after a ton of brainstorming, I think this will do what you want, the first input of the trigger will start the timer, the second subsequent input (from the horses tail, etc.) will cause the 4017 to reset, which will have the timer ready for another input, unfortunately, you will need 2 inputs to start the timer and 2 inputs to stop it..... but that should not be a problem since the horses tail seems to be triggering the module twice....


    Target Input Delay.png

    B. Morse
     
  11. retched

    AAC Fanatic!

    Dec 5, 2009
    5,201
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    no, no, no... You guys are going about it all wrong...

    ..Just cut the horses tails off.


    Problem solved.
     
  12. barrelracerdad

    Thread Starter Member

    Jan 29, 2010
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    0
    BMOrse, the only problem I see with the curcuit (everything has to be complicated) is that it doesn't trip twice everytime you run through it, maybe only once in three do we get a double signal, so the reset of the delay counter won't be reliable. I am stumped, but I may build the delay circuit and see if it works. J:)
     
  13. barrelracerdad

    Thread Starter Member

    Jan 29, 2010
    92
    0
    Didn't see retchs post, solution would work for me, could start a side business selling fake tails for horses (they really sell real horse hair fake tails, not kidding bout that, really expensive too)
     
  14. BMorse

    Senior Member

    Sep 26, 2009
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    Yeah, I kind of figured there were more variables at play here.... just thought this one might be do able...

    When you use the switches on the timer board itself and press the start switch, does it start as soon as you press it or after you let go of the switch?? I am just trying to still figure something out better than the counter circuit...

    and is there anyway you can trace the timer circuit (+) input for the start switch and see what value the resistor is that is pulling it high, (You could always take a clear, large picture of the circuit board, top and bottom so I could see for myself....), I am assuming it is a 10K pullup they are using, but I just need to make sure.....

    P.S.
    You and the family getting a lot of riding time in this summer??

    B. Morse
     
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