First off I would like to say that i'm new to this forum and new to circuit and electronics. With that being said, I can build of fix about anything if i have a little direction and understanding of how it works. What i am wanting to build is a simple Laser break beam sensor that runs off of a simple laser pointer. I am wanting the rec to trigger a 12v relay to power some lights. The Rec would also run off of the same 12v lawnmower or car battery. As for the Laser, I am wanting to run it off of a 9v battery. The sensor, and laser do not have to be no more than 10' to 12' apart. For a little idea of what im building, I host ATV drag racing and i am wanting to build break beam sensors to work as staging light for the drivers. What i am looking for is a good "Simple" detailed diagram to show me what I am doing. I have found others but none were exactly what i needed. Thanks

 

You may be farther ahead to switch from a laser to infrared for you project. There are many ready made products that can be adapted to what you want to do. Most garage door openers even use them as safety switches, to stop the door when something is in the opening.

 

Thanks for the quick reply. I was thinking about the garage safety switch, but would like for it to be two stand alone (wireless) sensors to keep from having to run wires across the track. And the IR sensors seemed like it may be harder for me to do with out good help. Im not stuck on the Laser idea so i would be open to any suggestions. So, what do you think the best solution for me would be?

 

Have a look at the Ramsey LTS1 kit.

http://www.ramseyelectronics.com/downloads/manuals/LTS1.pdf

 

tracecom, That looks like what i am looking for. It give a detailed description to what part are required and a good diagram to do it... I would not want to do the buzzer part. What would i have to do to do away with that part. And would that set up if powered by 12v, be enough to switch some light on?

 

As you probably noticed, they left out the schematic, so there are some questions still remaining. However, it seems that there is a relay included that could be used to turn on lights. The buzzer can just be left off.

 

Yea, I noticed it didnt have the schematic with it. I did see the diagram of were everything goes. I just assumed that it was just me being a Rookie and not being able to understand it. It looked like something like that would work good for my application. I could have the tran and rec on same side and bounce signal back with a mirror (would be only one power supply to worry about. Now I just need to find a schematic that would be something near that

 

Yea, I noticed it didnt have the schematic with it. I did see the diagram of were everything goes. I just assumed that it was just me being a Rookie and not being able to understand it. It looked like something like that would work good for my application. I could have the tran and rec on same side and bounce signal back with a mirror (would be only one power supply to worry about. Now I just need to find a schematic that would be something near that

How many do you need: one for pre-staged and one for staged? Unless you already have a lot of the parts, by the time you buy parts and pay shipping, you might be better off to buy a couple from Ramsey/Amazon. Plus, you get a PCB that you can assemble in a lot less time than you can build them on stripboard or perfboard. Of course, I like doing that, so I often don't take my own advice.

 

I'm going to need 4 total. One for prestage and one for Stage per side. Once I get them working, I am wanting to find a way that when both of the stage eyes are blocked (Both racers are staged and ready) that it will do a 1-2 sec delay and turn on a warning light. When the warning light turns on, i want a 1-2 sec delay and the 4 green (go) lights turn on. So the system will be fully auto. I like to be able to build my own thing to be able to say i done it. but in this case, i may be better to start with 4 kits and add to it. Would be a good learning opp. Does what i am wanting my overall goal to be sound do able?

 

I'm going to need 4 total. One for prestage and one for Stage per side. Once I get them working, I am wanting to find a way that when both of the stage eyes are blocked (Both racers are staged and ready) that it will do a 1-2 sec delay and turn on a warning light. When the warning light turns on, i want a 1-2 sec delay and the 4 green (go) lights turn on. So the system will be fully auto. I like to be able to build my own thing to be able to say i done it. but in this case, i may be better to start with 4 kits and add to it. Would be a good learning opp. Does what i am wanting my overall goal to be sound do able?

For the timing that you describe, there will be some additional circuitry required, but it is all doable. As to the LTS1 circuits, I would probably order one kit (which will contain the schematic) and make the others that I needed, but it would be easier to just order the kits.

 

Sounds good. Sorry for all the questions, I just didn't want to get $100+ and several hours into this project and find out i need to start out with something different. So With one of these kits, I can can power it with 9v battery (i understand that from plans), and have it switch a AC relay to power lights? Or would the whole system need to be on DC? One more question. This one is for after I finish this project ( I'm sure everyone knows how it is when you have projects racing in you head). If I build 2 break beam sensors, one on each lane at the finish line. Can I have it where the first beam to break turns a light on for 5 sec and blocks the other beam from triggering the relay. Once again, sorry for all the questions, I'm just the type that likes to have it all planed out in my head before i start.

 

Looking at other projects on that sight, i found this.

http://www.ramseyelectronics.com/cgi-bin/commerce.exe?preadd=action&key=MK120

Would it work for my application with a few modifications and could 2 of these be used side by side without interfearing with each other?

 

So With one of these kits, I can can power it with 9v battery (i understand that from plans), and have it switch a AC relay to power lights? Or would the whole system need to be on DC?

Please understand that I have never used an LTS1; in fact, I have never seen one. I am just going by the manual, which says, "The Base-Emitter junction of Q6 is in turn forward biased through R7 and the Relay K1 turns on to trigger your external circuit (connected via pads P5 & P6)." It doesn't say what the ratings of the relay contacts are rated for, but a "bullet point" at the beginning says, "• 5 Amp External Trigger Relay Output for custom drive applications!" so, I would think it can switch at least 5 amps of AC, but to be sure, you would need to check with Ramsey.

One more question. This one is for after I finish this project. If I build 2 break beam sensors, one on each lane at the finish line. Can I have it where the first beam to break turns a light on for 5 sec and blocks the other beam from triggering the relay.

In principle, yes, but once again, there will more circuitry involved, which you (or someone) will have to design and build. There are people here who will try to help (including me when I'm available,) but it's a fairly complicated project given all the bits and pieces involved.

If it was my project, I would buy one kit, build it, test it, play with it, and try it out with the ATV's to see what it will do and won't do. If you do that, you can see if it will actually perform in the working environment, including such things as whether or not an ATV will break the beam, and if it will switch the lamps you are going to use. Once you are satisfied with those two answers, you can begin work on the timing circuits to control the LTS1 modules. In addition, you will learn enough to decide whether or not you want to buy more kits (or build your own); also, you will undoubtedly have some new/better ideas as to the physical mounting as well as the timing logic.

As I write this, it just occurred to me that, because you want a delay between when the beams are broken and some lights coming on, some timing circuitry will have to be implemented between the sensor circuitry and the relay operation. This is just one of the complications that you will have to deal with. Only you can say whether or not, it's a project that you can handle. I can tell you that contingencies will arise that are presently unforeseen.

 

Looking at other projects on that sight, i found this.

http://www.ramseyelectronics.com/cgi-bin/commerce.exe?preadd=action&key=MK120

Would it work for my application with a few modifications and could 2 of these be used side by side without interfearing with each other?

I thought you said you didn't want to use IR. IR will be more finicky to deal with in an outdoor environment.

Here's the link to the details of the MK120; it's a Velleman kit and they publish the schematics.

http://www.vellemanusa.com/support/downloads/?code=MK120

 

I thought you said you didn't want to use IR. IR will be more finicky to deal with in an outdoor environment.

OK, I'm not really sure what I need I guess. I thought I saw somewhere that IR sensor would work better in ambiant light. Just looking at options. That is kinda my plan, to get one and try it out and go from there. This is nothing i'm wanting to build over nite. Just wanting to make sure I am heading down the right road. I really appriciate you taking the time to answer some of my questions. Knowing that it will work in principal give me enough steam to tackle this project. I know after starting it there will be no stopping untill if figure out a way to make everything work. As with other projects that have lead to sleepless nite and hours of research on forum. Thanks again

 

Thanks again

You're welcome. IR might work; I have no experience with it, but my concern would be the heat from the engines and the track. The MK120 is cheap; buy one and try it. If it works, it's cheaper than the LTS1. Good luck.

 

Review: One beam break for pre staging, 2 for staging & 2 for end??
Laser works quite well, needs stable pointing, easy detection, no cross coupled interferance, Post 12 = NO. Post 11 = Yes. I purchased a laser diode module for US $ 2.95. 5 V @ 30 mA. Receiver might be just a photo transistor & FET to directly control DC lights. Delayed lights , a few 555's.
Are lights operated from 12 V battery or is AC available.
For fun reading try in find box: Laser receiver / detector by NewbieDoug

 

AC is available and would be my first choice but 12 v battery is not a problem either. Right now i have everything setup with everything running on AC thru a switch box and i have to manually turn lights on. And it is 2 for prestage and 2 for stage.

 

Thanks Bernard,
Do you have some tips for me are maybe a simple diagram with a shopping list on what would work good and be simple for a novice?

 

To my way of thinking, the MK 120 would be a good choice as it uses a modulated IR beam which helps cut down on light polution of receiver. The receiver would be easy to interface with timing ckts. Aiming also will not be as critical as laser. Might put transmitters on outside of each lane & both receivers in center with timing ckts & light pole. Use a 9V regulator from the 12 V battery, or if 120 AC is available, 9V wall warts. Timing ckts drawing maybe tomorrow.