HELP! 10 SSC P7 LEDs in offroad racing light

[LEDobsession]

8 SSC P7 LEDs in offroad racing light

Hi, Im new to this forum but im in the middle of making an offroad LED light using a number of SSC P7 leds. I want it to be similar to the Vision X Xmitter high intensity light bars like the 42" one I bought ( IT'S DAMN BRIGHT!).

I am a machinist and today I made a reflector cup set up that im hoping will double as some of my heatsinking for the light. I will also be building the rest of the casing and electrical stuff once i can figure out what to drive 8 P7s on a 10-14 volt dc system for my Honda TRX450r (kickstart version).

The 42" Vision X Xmitter I bought is labeled to run at anywhere from 8 to 32 volts DC. If anyone can help me figure out what to drive them with and tell me if a solid aluminum casing with aluminum reflectors and possibly some machined cooling fins will be enough for the heat of the light, that would be awesome.

Thanks, Trevor.

 

[LEDobsession]

I would post some pictures if I could figure out how to put them on.

 

[LukeA]

If you've got fins and you're moving with the light on you shouldn't have heat problems.

Have you tried out your reflectors? There's a lot of design work in getting a good beam.

Driving those emitters will be a little bit of a challenge. I would think three 1A buckpucks in parallel driving each string of three P7s would work well.

Photos: upload them to Photobucket and copy the image code for forums and paste it into your reply.

 

[LEDobsession]

Heres a few pics:

[/IMG]

Optics tested with my ssc p7 minus the flashlight reflector. Hopefully this will be good enough optics once I mill off the back side of the reflector (I left it a little thick) it seems to work good enough for the Vision X light bars. I kind of guessed with my designs on mastercam, but with one p7 in part of the reflector, it seems to work pretty good.

[/IMG]

The Vision X light bar is what I used as my design, such as the overlapped reflector cups to blend the emitters light pattern into each other, and some of the dimensions. As you can see, I didnt do too bad on the copy of the design.

[/IMG]

Application on my Honda TRX450R:

[/IMG]

As for fins, I will most likely be using a .5" to .75" long 1/8th dia. endmill for some cooling fins in the back of the light casing like the Vision X has done with theirs

 

[rushnrockt]

Just wondering, what is the budget for anything that you would like to power the LEDs for?

I am not familiar with the motorcycle/atv world, is it still a 12V system? Automotive power supplies are quite dirty and since I do not know what the buckpuck (recommended above) uses, it might not be quite enough to survive. I'm interested in your progress since I would like to do something similar for my truck

 

[LEDobsession]

Here is what the beamshot looks like (on a painted wall) with about .1" of aluminum that I may still need to mill off the back side of the reflector.

[/IMG]
Sorry about the huge crappy pic

As you can see, there is a visible projection of the P7's quad die in the middle. Hopefully, milling off the back and bringing the emitter out into the reflector bowl will help eliminate the visible die pattern. There are also 2 mickey mouse ears showing that will help blend the beam patterns together. Where can I get some good 1 amp Buckpucks? I couldnt find any on DX but maybe I wasnt looking hard enough.

Thanks, Trevor.

 

[LEDobsession]

Umm, well my budget is limited to what I want to put towards this instead of my '68 Chevelle (which is an endless money pit) because Im single and make decent money as a machinist. Haha. I still need to spend about $150 for 8 Emitters from DX at about $18 bucks a pop (Anywhere cheaper?) Any ideas for drivers, I will consider cost-wise because I want to make this to last.

Typically, most ATVs and Motorcycles run on a 12 volt system but Im not quite sure about the amps and stuff (I guess I could take a multimeter to it and see) and since my ATV does not have a battery (good ol' kick start), I will be running it off of the magneto, so I will need to check into that. Since this is going to be on my sport quad, this will probably be just as dirty as any automotive power supply, but I intend on making this extremely weatherproof and durable. If I can make one good enough, I may even make another. The hardest part so far has been sanding and polishing the reflector plate by hand (took about 3 hours and that was in a hurry).

Thanks, Trevor.

 

[LukeA]

If's you're looking at the BSYPI P7s from DX, look elsewhere. Those are dim and blue. Get the C-bin ones, they're brighter.

Buckpucks don't come from DX, they come from here.

Buckpucks do work with dirty automotive power, especially such a simple system as this.

 

[LEDobsession]

The Emitters from DX I have been looking at are labeled as C-bin and they have the soldered heatsink attached. They are also claiming up to 900 lumens. I checked out the "BSYPI" P7's to see what they are and when I first saw those a while back, I decided against them because they are only rated 570-740 lumens, they dont have an attached heatsink (I dont know for sure if I will need that on them but, its not bad to have just in case), and they cost a wee bit more. So if the C-bin labeled ones from DX are what I should get, I will go with those. By the way, thanks for your help guys.

I just now realized that I messed up my title. This is not going to be 10 LEDs, it will only be 8. Ill have to fix that. Sorry for misleading anyone.

 

[LukeA]

That's not really a heatsink. It's just a star. It only allows you to mount the LED to its final heatsink more easily. You still need lots more mass and surface area. Here's a good source for large heatsinks.

 

[LEDobsession]

I could get one of those, but I was thinking of just incorporating some cooling fins into the rear casing by machining them with maybe a 1/8th" endmill plus this thing will be all aluminum and I still have to design and make the casing parts. But I havent ruled out buying a pre-made heatsink. Do you think I should use one of those to mount the emitters onto internally? If I could do that, I would maybe get that HSK 200478 off that site and cut it in half and put that inside with the LEDs mounted to it. But I would typically think that you would want any cooling fins on the outside, not the inside so maybe that wouldnt work too well. I still would like to keep the depth of this thing around 3 to 4 inches, so that all depends on the buckpucks, internal heatsinks, and wiring.

Thanks, Trevor.

 

[LukeA]

Yeah, fins on the inside are basically worthless except initially as low-temp mass that can absorb heat.

The design has to allow for a direct connection from the back of the stars to the outside, preferably lots of outside. If it's still open design-wise, then you could certainly just mill the fins into the back. As long as you're ok with a loooong milling operation. But if it's CNC that doesn't matter too much.

If you wanted to leave plenty of room for electronics you would leave about .80-1.00 inches deep and the size of your reflector plate or so.

 

[LEDobsession]

I'll have to draw up something for the stars to mount onto that will go directly to the back for some cooling fins and throughout that allow wiring to pass and I think I can work the buckpucks into the outer part of the light.

I think with the .5" reflector plate, .125" Lexan lens, .5" buckpucks, Emitters & stars, and maybe a backplate combined into a heatsink mount, I will be able to make this around 4" deep, which I am ok with.

My cooling fins will be somewhat CNC machined, being that I will use MasterCam and a Bridgeport EZ-Trak Mill that accepts G & M coding. All I have to do is raise and lower my Z axis, but I am fine with that fact and have been using it for a long time now. Thats what I used to make the reflector plate and it worked out great.

This is really coming along inside my head. Now all I need to do is get some time and money, then order my LEDs and the buckpucks, and cut out the rest of it. Hopefully that wont take too long because Im too impatient. So, do you think the C-bin emitters with the attached heatsink from DX (http://www.dealextreme.com/details.dx/sku.12721) will be a good choice for me? Thanks for your help LukeA.

 

[LukeA]

Yes, I think the C-bin P7s will work if you get some thermal compound under them and screw them to the heatsink.

 

[LEDobsession]

Driving those emitters will be a little bit of a challenge. I would think three 1A buckpucks in parallel driving each string of three P7s would work well.

Hey Luke, since I'm doing 8 P7's, would (4) 1Amp buckpucks be good for each set of 2 emitters in parallel instead of the 3 idea?

I have the design made up for the base/heatsink as well as the faceplate and I'll post the pictures as soon as photobucket finishes their site maintenance. My design for the base is based off using 4 1A buckpucks. Hopefully it will work like I planned. I will most likely be wire EDM-ing the fins into the back instead of milling them out.

 

[LukeA]

Hey Luke, since I'm doing 8 P7's, would (4) 1Amp buckpucks be good for each set of 2 emitters in parallel instead of the 3 idea?

I have the design made up for the base/heatsink as well as the faceplate and I'll post the pictures as soon as photobucket finishes their site maintenance. My design for the base is based off using 4 1A buckpucks. Hopefully it will work like I planned. I will most likely be wire EDM-ing the fins into the back instead of milling them out.

If you're running the P7s at 2A might I suggest simply keeping the strings of P7s separate? It will guarantee that the P7s each receive exactly 2A. If they're in parallel one string (the one with the lower total forward voltage) will take more current, and there can be problems associated with that.

An issue is that you may need 6 buckpucks to run 8 P7s at 2A. From DX, chances are that the P7s won't have a Vf low enough to allow you to run 4 in series from 14V. You may get lucky and get P7s that will work that way, but I'd go with the odds.

There is another option. In the past few months I've been looking at very low cost solutions for driving LEDs and I think I have found one that will work for you. If you get high Vf P7s, you can run series strings of 4 with AMC7135 boards wired like this, but with ~14V from your bike and 4 P7s in series. This option is much cheaper and smaller than 4-6 buckpucks, so going with AMCs may allow you to thin the design down some.

 

[LEDobsession]

There is another option. In the past few months I've been looking at very low cost solutions for driving LEDs and I think I have found one that will work for you. If you get high Vf P7s, you can run series strings of 4 with AMC7135 boards wired like this, but with ~14V from your bike and 4 P7s in series. This option is much cheaper and smaller than 4-6 buckpucks, so going with AMCs may allow you to thin the design down some.

Yeah, I saw those AMC7135's on the discussion board in DX on the P7 page and wondered about those. I see that there are a couple of different mA's to choose from. Would I want the 1400mA (1.4 A) set using 2 in parallel seeing how the p7 is supposed to be run at 2.8? Will it be taking a risk with varying Vf on multiple C-bins, or do you think that they will all be close enough to not produce problems? How high of Vf do they need to be?

If this will work, that will be awesome to save money and slim down my designs. I was really not wanting to spend $60-90 on 4-6 buckpucks, but if it all comes down to it, I'll use them if I need to.

Heres the other 2 designs I came up with on MasterCam last week and the previous design as well:

This would be the base/heatsink for the emitters and drivers.

The reflector (Already made and I finished milling off the other side. It is now to size.)

This is the Faceplate that will cover over the lexan lens and the reflector plate. It will have the same outer dimensions as the base.

 

[LukeA]

Yeah, I saw those AMC7135's on the discussion board in DX on the P7 page and wondered about those. I see that there are a couple of different mA's to choose from. Would I want the 1400mA (1.4 A) set using 2 in parallel seeing how the p7 is supposed to be run at 2.8? Will it be taking a risk with varying Vf on multiple C-bins, or do you think that they will all be close enough to not produce problems? How high of Vf do they need to be?

The AMC chips run in parallel just fine. In fact that's how they get the different mA ratings for the boards. A 700mA board is just two chips in parallel, a 1050mA has 3, and a 1400 has 4 chips in parallel. The same trend continues to get 2800mA.

Running two separate series of 4 P7s with AMC boards won't have the current-sharing problems that running them in parallel series will have. You won't have any problems using two 1400mA AMC boards in parallel running one string of P7s.

Your drawings look good. If your mill can do it, it may be worthwhile to have it drill and tap your screw holes.

 

[LEDobsession]

Your drawings look good. If your mill can do it, it may be worthwhile to have it drill and tap your screw holes.

Oh yeah thatll be next. I now have access to use the CNC machines at work and school. I just did the design to give me an idea of what I want it to look like. Now, all I have to do is wait for those drivers to get off back order, buy the emitters, cut out the base and Ill be set.

 

[LukeA]

Oh yeah thatll be next. I now have access to use the CNC machines at work and school. I just did the design to give me an idea of what I want it to look like. Now, all I have to do is wait for those drivers to get off back order, buy the emitters, cut out the base and Ill be set.

There's a thread in one of the other subforums about that. The 10 pack may never be in stock.