Simple finish line circuit help

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MT Pockets
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Simple finish line circuit help

Post by MT Pockets »

Greetings,

I need some help from the electronics gurus here. Our church derby used an old wooden track without any timers, or finish line "judges". Last year, my brother built a simple finish line unit with micro momentary switches built into the track, connected to an arm that the car runs over, and simple lights over each lane to indicate the winner. problem is, the cars go by really fast, and it's often hard to see which one went on first if your not watching close. They are often just a quick flicker.

I would like to build a whole new setup, but dont really have the time or money right now. Is there anything that can be added to the circuit that would hold the winning light on until it's rest somehow?

I know it's hard not seeing the actual unit, but here is a diagram that sort of shows what we have. of coarse it has one on each lane. If I remember correctly, I think that he wired it in a fashion that once one light came on, the other one didn't

Thanks,
MT Pockets

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Re: Simple finish line circuit help

Post by gpraceman »

There are plans and kits for the Do-It-Yourselfer listed at http://grandprix-race-central.com/modul ... page&pid=5.
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Re: Simple finish line circuit help

Post by MT Pockets »

Thanks for the links I will definitely take a look. I was hoping that one of the guru's on here would be able to give me an idea to quickly modify what I already have to work with by adding a component or two, and maybe a reset switch, and get this going for this year, then have enough time time to redo the track and timer setup for next year.

It works fairly well, it would just be nice to have the win light stay on longer, and then either go off after a short time, or be reset with a switch. I dont need any timer functions, or anything fancy.

I may be asking for the impossible, and just need to start over from scratch for next year.

Thanks,
MT___
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Re: Simple finish line circuit help

Post by dna1990 »

It is hard to say without knowing more about the circuit you already have and what components/voltages it may be using.

But in the electronics world, you want a 'latch' circuit of some type.

Perhaps for this simple get-by-this-year operation, a set of simple 'capacitors' could work. Think of them as charging up and will continue to provide power to the bulb for a short time after the actual switch is turned off. Depending on voltage, this should be done with care.

Maybe this gives you enough to search around for.
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Re: Simple finish line circuit help

Post by Darin McGrew »

Just brainstorming...

There may be a clever way to wire DPDT switches, such that throwing a single switch provides power only to the bulb for that lane, but throwing additional switches provides power to all the bulbs in series. The effect would be that the bulb for the first car would light brightly as it received the full voltage, and then the bulbs for all the cars would light dimly as the voltage is divided among them.

But an electronic gate of some sort is probably a better choice.
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Re: Simple finish line circuit help

Post by MT Pockets »

I will have to go to church and pull out the track and draw a diagram of how it's wired. I don't think it's a complicated circuit from what I recall. The latch circuit sounds like it may work. The voltages are low since we were running it off of 4 AA batteries.

The DPDT switches Darin mentions are what I believe that we used, he got them at Radio Shack. I have some pictures of the setup before it was wired, but of coarse don't have any after since we were running out of time when we did it. I wouldn't be opposed to switching it over to another type of power supply if it would work better with the latch circuit setup. I'm open to ideas, and at this point we only desire to know who crossed the finish line first and will worry about times when we get a new track, or redo this one since it's very old.

It had some old, non working finish line setup on it, which we removed and built this one from scratch. I noticed in the pic that shows the batteries, only three are in there, LOL, we used four when we ran the race though

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Re: Simple finish line circuit help

Post by John Shreffler »

Send me the distance between lane center lines and $20 and I will send you a Judge made from left over parts of early years. I don't mean to spoil your fun, and I do like the skill of the woodworking.

Randy: At this price, you can't consider this commercial.
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Re: Simple finish line circuit help

Post by MT Pockets »

WOW! What can I say, but THANK YOU!!!!

I wouldn't call it spoiling the fun, I call it a God send. It seems that time is in short supply these day's, and we would be forever grateful. We've used the track so long without anything just eyeballing the races, we wont know how to act. Just pm or email me where to send everything, and I'll get it off to you. I will stop by the church tomorrow and get some measurements for you.

Thank You, Thank You, Thank You!

Gene

PS. Did I say Thank You?
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Re: Simple finish line circuit help

Post by John Shreffler »

My mailing address is on all pages of my web site www.newdirections.ws You will be much happier with infrared detection, nothing touches the cars. Along with center line separation, give me the width of the track deck.
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Re: Simple finish line circuit help

Post by MT Pockets »

Thanks again John,

I'm sure we will be very happy with it!
I will the get everything off to you sometime tomorrow.

Regards,
Gene
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Re: Simple finish line circuit help

Post by gpraceman »

John Shreffler wrote:Randy: At this price, you can't consider this commercial.
I'll let it slide, since you are not likely making money on the deal.

So, what else do you have sitting on your shelves collecting dust? :lol:
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Re: Simple finish line circuit help

Post by MT Pockets »

Thanks John for getting us setup with a finish line that will work. Sorry for the delay in posting, it's been crazy. I will post some pics when I get it installed and of pics of the race too. Our race is March 25...

Thanks,
MT Pockets
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Re: Simple finish line circuit help

Post by MT Pockets »

I finally got the finish line Judge that John so graciously hooked us up with installed on the track. I changed the mounting brackets so that we could mount it in the finish line tower that we already had, and in the process it was necessary to move the battery pack from the original mount to the wood tower, and installed an on\off switch at the same time. The only regret that I have is running out of time and not getting it painted, and those silly lane numbers removed (maybe next year). We tested it with the cars that my wife and I made for our cub scout family division. Everything works great and the boys are really going to appreciate knowing for sure who actually won this year!

Unfortunately, I just found out that I will be needed at work this evening and will not be able to be at the race, but hopefully someone will take some pics for me.

Here are a couple of pics of the Judge installed....Thanks again John!

We didn't have all of the lights on, so was kind of dark and the pis are not the best..
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Re: Simple finish line circuit help

Post by John Shreffler »

hmmm. It seems like it would have been less work to throw away the tower, and just mount the Judge with 4 screws provided. No painting needed. But as long as you are happy, hey, you are happy customer number 4485, owner of the least expensive Judge ever sold. :D
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Re: Simple finish line circuit help

Post by MT Pockets »

Yes, it definitely would have been a whole lot easier but, as usual I was trying to please the majority. It was a little more work, but it worked out well.

I used the router table to cut a slot in the board that goes under the track to mount the circuit board in, keeping it safe from damage (I'll post a pic). Also, by fixing the judge to the tower, we just had to remove 2 screws and the whole unit comes off so that in can be stored somewhere safer than under the stage where damage is possible.

Yes, we are extremely happy with the judge, it performed flawlessly...

Thanks Again John,

Gene
aka MT Pockets
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