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HELP-Manual Stop Light for Children's Church

Discussion in 'Electronic Design' started by Darin, Sep 24, 2012.

  1. Darin

    Darin Guest

    Hello. My name is Darin Roberts, I am the children's Pastor in Tarpon Springs Florida.

    I have some experience in building ic projects from schematics, but have never really learned how to create the schematic my self. So far I have made a 4 player quiz circuit, and a 32 channel random selector. Now I am looking at wanting to build a manual advance stop light system.

    I would like to push a button - dpst - having one throw go to a buzzer which will sound for as long as the button is pushed. The second throw will send a signal to the IC board to move the indicator from where it is to the next color. Red (push) Green (push) yellow (push) Red...... I will use a triac on each channel to power the A/C light in the Stop Light Unit.

    As I said, I have a VERY small understanding of how and why different IC chips are used, but I do have a few basics. I looked at using a 4011 NAND gate to make sure the signal from the switch is clean. From there, the best Schematic I found was to feed the clean signal into a 74LS191n, to a 74std154n with a 74F112n (this was for a Night rider light or a dragster tree).

    My church is on a limited budget and I am also on somewhat of a time crunch, so I have not had the resources to try to buy stuff and breadboard it out.. I would hate to buy parts and not have it work, and have to buy more.

    Can you please assist me? I am willing to build it, and buy the parts, I just need the schematic.

    Thank you for your time and consideration.

    Darin Roberts
    www.kidpreacher.org
    727-809-0926
     
  2. hamilton

    hamilton Guest

    Very simple project for sure.

    Will this be used by kids ?

    If so, the push button will be pushed many times not just once per light
    change.

    Would a hold off of say 1-2 (5-10) seconds help in keeping for lights
    from move Red, Green, Yellow,..... to quickly ?

    I am sure that many people here can help you with all sorts of ways to
    complete this.

    To re-cap the hardware:

    1 input switch

    1 output buzzer

    3 output lights ( via triac )

    To re-cap the functions:

    a) Push button (make contact)
    b) Buzzer sounds
    c) light changes one state R -> G -> Y -> R
    d) Release button
    e) Buzzer stops

    hamilton
     
  3. Hi Darin, This sounds simple. Look up a MC14017 on digikey (or
    somewhere) Once you've got the input debounced (the hardest part
    perhaps) send the pulse train into the MC14017 you get three separated
    signals out. Then you just need to reset the thing on the third
    output. (I think just hooking Q3 to the reset will work.)

    As for the power do you need big lights or would LEDs work too? If
    you do want the big lights then maybe three relays would be better
    than triac's. (At least that would be easier for me.)

    George H.
     
  4. tm

    tm Guest

    Hi Darin, This sounds simple. Look up a MC14017 on digikey (or
    somewhere) Once you've got the input debounced (the hardest part
    perhaps) send the pulse train into the MC14017 you get three separated
    signals out. Then you just need to reset the thing on the third
    output. (I think just hooking Q3 to the reset will work.)

    As for the power do you need big lights or would LEDs work too? If
    you do want the big lights then maybe three relays would be better
    than triac's. (At least that would be easier for me.)

    George H.
    ==================================================

    Might be safer if you designed it to use leds and ran everything on 12 volts
    DC. Especially if kids are involved.
    Use a wall wart power supply and there won't be any certification issues,
    hence no insurance problems.
     
  5. Joerg

    Joerg Guest

    Easiest would be to "cheat" and pull something similar off the web, like
    this:

    http://www.electronicdesignworks.co...ontroller/simple_traffic_light_controller.htm

    In your case you'd wire up IC1 (which is a simple NE555) as a one-shot
    instead of an oscillator. Meaning a push of a button results in a pulse
    of pre-determined length. That de-bounces your push button so you no
    longer have to worry about that. You'd also hang a buzzer on your
    push-button for the sound effect. You probably also don't want to
    combine and return to reset on an earlier count than they do.

    Relays are best and safest. If you aren't too experienced my suggestion
    is to stay away from triacs because with those you would not have a real
    isolation between mains stuff and your low voltage circuit. Play it
    safe, especially with kids aroudn how might decide to open things up
    some day.

    Attention: This circuit has a flaw, they forgot the flyback diodes
    across the relays. I'd use a ULN2003, it has 7 relay driver transistors
    plus 7 diodes built in and only costs about 30c in singles. Tie the COM
    pin to your relay supply voltage:

    http://www.ti.com/lit/ds/symlink/uln2003a.pdf

    They also didn't handle the reset properly but you could just press the
    button until you get to the desired start position.
     
  6. mike

    mike Guest

    Why are you doing this?
    If you want to learn how to wire hardware bits together, you're on the
    right track.

    If you want to make something for the kids...a RESULT,
    buy an Arduino board or similar and do it in software.
    You'll learn a useful skill.
    You can make lots of different demos for the kids easily, once
    you get set up. The stuff is available at Radio Shack, but it's
    cheaper on EBAY.
    You can even let the kids edit the software.
    Everybody wins.

    I'd bet you even have someone in the congregation who'd help
    get you started.

    Or, you could just write a simple computer program that simulates
    the lights on the screen. Or use the parallel port to work the
    switches/lights.
    I'd bet you even have someone in the congregation who'd
    donate a computer and teach you how to do it.
     
  7. Jasen Betts

    Jasen Betts Guest

    The MOC3010 datasheet has a good triac driver circuit

    cheaper than a solid state relay, more reliable, (if not cheaper than)
    a mechanical relay.

    but yeah, low voltage LED is to be preferred if practical,
    if connecting LEDs directly fo thr '4017 isn't bright enough

    Having a 12V supply, with the '4017 driving darlinton transistors
    driving perhaps 3 or 4 high-efficiency LEDs in series might be
    enough.
     
  8. hamilton

    hamilton Guest

    You still need the triac with this.
    A Solid state relay in an MOC3010, a triac and passive parts in one package.

    May not be cheaper than the two parts but is more convenient.


    hamilton
     
  9. Guest

    You asked the reason - Result. Fast, simple, RESULT. As a children's minister, I daily deal with kids on meds, family counsiling, web site maintainance, graphic design, music......... It always seems I come up with great theme ideas, just never sure how to get it done, and don't usually have thetime to study and develop another new skill. I know how to solder, I knowhow to run wire, so learning to build IC boards was not a huge stretch, aslong as someone gives me the schematic with pin outs. Conect A to B, Pin 2 to Pin 5..... I asked people in congragation, no one is in that field. So I turned to groups. I appreciate all the help.

    This circuit is actually going to be done 2 times, once for the boys side, once for the girls side. If one group of kids starts to get out of control, I push the button, and light goes to yellow - at red, their side does notget to participate in games at end of service (time waiting for Adults to finish). Sort of a positive peer preasure thing. One stop light for each side.
     
  10. ehsjr

    ehsjr Guest

    It would be more flexible, more reliable and a lot easier for you
    to use 2 spdt toggle switches for each side, and a single on/off
    switch (not shown) to turn Vin on or off. The circuit below will
    work with either AC or DC.

    Sw1
    Vin ---o o---------redbulb------+
    \ |
    o---o o---yellowbulb---+
    \ |
    o----greenbulb----+
    Sw2 |
    Vin -----------------------------+

    With the above, turning on yellow (sw2) turns off green, and
    turning on red (sw1) turns off yellow (or green if you want
    to go directly from green to red).

    That way it gives you the flexibility to go from yellow back to
    green or from red back to yellow (or green) if you want, and the
    position of the toggles tells you what light is supposed to be on.
    With the push button scheme you are stuck going in one direction
    only, and an accidental push of the button would require cycling
    through to get back to the correct color.

    Ed
     
  11. Or maybe just a multipole rotary switch.

    George H.
     
  12. mike

    mike Guest

    I daily deal with kids on meds, family counsiling, web site
    maintainance, graphic design, music.........

    It always seems I come up with great theme ideas, just never sure how
    to get it done, and don't

    usually have the time to study and develop another new skill. I know
    how to solder,

    I know how to run wire, so learning to build IC boards was not a huge
    stretch, as long as someone

    gives me the schematic with pin outs. Conect A to B, Pin 2 to Pin
    5..... I asked people in congragation,

    no one is in that field. So I turned to groups. I appreciate all the help.
    Sounds like a lot of work to replace two sets of colored paper dunce caps.

    once for the boys side, once for the girls side.

    Boys vs Girls???? This gets more interesting by the minute.

    If one group of kids starts to get out of control, I push the button,
    and light goes to yellow - at red,

    their side does not get to participate in games at end of service (time
    waiting for Adults to finish).

    Sort of a positive peer preasure thing.

    Sounds to me more like a stick than a carrot.

    One stop light for each side.
     
  13. josephkk

    josephkk Guest

    Some questions for you.

    Is this a one way street? (how many signal faces?)
    Will the signal be portable (stored away except on meeting days and times,
    lots of permit issues here)?
    Does the signal need to be reasonably "crash safe"?
    Do you already have appropriate signing, striping, and pavement markings?

    Sorry, but this dropped in no more than the first circle out from the
    bulls eye of what i done for a living for the past ~20 years.

    Think carefully about whether / how you wish to reply.

    ?-)
     
  14. josephkk

    josephkk Guest

    For anybody that cares the load switches in traffic signals all over the
    US are solid state (triac and control electronics) for the past 20 years.

    ?-)
     
  15. josephkk

    josephkk Guest

    Oh, not on a street; big difference. That answers many of my questions.

    How big of an indication in inches do you need?
    I am going to assume perfboard construction as that is what i would likely
    do in this instance.
    In general tell us more about what you want.

    ?-)
     
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