forum Newbie>>engineering student with projects

[ArcTec34]

Hey everyone,

So I'm new to the forum. I'm a freshmen at Lehigh University in the Mechanical Engineering program. Somehow, one of my freshmen projects is to creat an LED light bar, similar to McGizmo's "cree bar"
Besides that, I'm currently hoping to mod a Mag light (not sure if I should use C or D) with a Seoul P7 LED, (oh, I can't find where to buy the C bin, as dealextreme isn't showing the correct bin, any help would be appreciated) and also trying to creat a custom heatsink using some tools at the University. I need some posts before I can PM people about heatsink specs and dimensions..

any help or prods in the right direction would be greatly appreciated!!

Brian

 

[kuksul08]

3rd year ME here :welcome:

 

[ArcTec34]

haha, cool. So I've been searching around a lot (good tool for a newb) about doing a Maglite to LED conversion. I will be making my own heatsink.
I don't know where to buy the brightest SSC P7 C bin LED, though, as dealextreme only shows less-bright bins.
Also, which is better to modify, a D-cell maglite, or a C-cell?

Any help or prods in the right direction would be greatly appreciated.

Brian

I found this http://www.dealextreme.com/details.dx/sku.12721 bin c emitter, but it has a 21mm heatsink base that i'd have to remove. People's comments on it talk about it being an i bin, not a j bin as the site shows.. what is the difference?

 

[Gunner12]

Check this thread for bin(flux, tint, Vf) stuff. The I bin has a lower Vf then the J bin.

PhotonFanatic has P7 on sale over at the Marketplace.

Any light should be fine for the mod as long as you have a good enough heatsink and the right voltage or a good circuit.

How much output would you like from the bar?

:welcome:

 

[ArcTec34]

Check this thread for bin(flux, tint, Vf) stuff. The I bin has a lower Vf then the J bin.

PhotonFanatic has P7 on sale over at the Marketplace.

Any light should be fine for the mod as long as you have a good enough heatsink and the right voltage or a good circuit.

How much output would you like from the bar?

:welcome:

thanks for the links, I'm looking for around a 1,000 lm output
EDIT: thanks for the P7 ordering info, just registered in the marketplace and looking to order a few P7s as soon as i can..

In other news, I have to build the heatsink myself at our machine shop for our projects, so I'm scouring for specs of the ones that some of the members are selling..

 

[Gunner12]

1000 lumen, what power source? What tint?

If you are using single die LEDs 4-7 LEDs should be fine for the task(depending on tint and current to the LED). Quad die LEDs, you won't need more then 3 of them.

 

[ArcTec34]

power source will be adapted from a standard wall outlet, don't really care about tint. I'll probbaly use 7-ish single die LEDs..

 

[LukeA]

thanks for the links, I'm looking for around a 1,000 lm output
EDIT: thanks for the P7 ordering info, just registered in the marketplace and looking to order a few P7s as soon as i can..

In other news, I have to build the heatsink myself at our machine shop for our projects, so I'm scouring for specs of the ones that some of the members are selling..

The only really important dimension is the outside diameter. The emitter pedestal needs to be a few mm high and should fit through the hole in the reflector. The height of the whole heatsink should be maybe 30-45mm. As far as what mag to use, it basically only depends on whether you want runtime or relatively compact size.

I like to remove the bulb tower from the mag's switch to allow easy soldering to the switch contacts. I typically break out the tower with a pair of pliers because A) the switch is made of glass-filled nylon and is hard on steel sawteeth, and B) chipping it off with the pliers is so satisfying.

 

[Gunner12]

That project actually doesn't seem too hard. Much if not all of the stuff you can buy. Get the right driver for the LED, IIRC some can power the LED directly from the wall power, mount the LEDs on a metal plate or some kind of a heatsink with the converter also mounted on the heatsink. A frosted plastic covering to cover it all and it should look pretty prefessional. There are some similar projects around here.

McGizmo has converted all or almost all of his house to LED lighting.

 

[ArcTec34]

yeah I saw McGizmo's hous LED thread, thats pretty amazing.

I ordered the LEDs, and I'll hopefully order the drivers tonight..
I found this thread so I'll follow it.. good stuff
http://www.candlepowerforums.com/vb/showthread.php?t=195358

 

[Gunner12]

Here's another guide.

Have fun with the mod!

 

[ArcTec34]

thanks
one question, the guy in that mod you just posted didn't use drivers... should I? does it matter besides different modes?

 

[Gunner12]

I'd recommend using a driver unless you are using 3 alkaline batteries or 1 Li-ion battery with a P7 of the J bin. He probably had a Seoul P7 of the right Vf bin so he doesn't need a driver to keep the current to the LED from getting too high.

The driver lowers or raises the voltage from the batteries to what the LED needs at the current the driver is supplying to the LED so unless the battery voltage is close to the LED's voltage, then you should at least use a resistor(if voltage is a bit above) or a driver.

What power source will you be using?

 

[Kryosphinx]

2nd year MSOE ME student here!

Just and FYI, when you apply for internships and such, tell em that you do this stuff. They like high-tech flashlight mods.

 

[LukeA]

thanks
one question, the guy in that mod you just posted didn't use drivers... should I? does it matter besides different modes?

From 1 Li ion/3Nimh, it doesn't really matter.

 

[ArcTec34]

I'd recommend using a driver unless you are using 3 alkaline batteries or 1 Li-ion battery with a P7 of the J bin. He probably had a Seoul P7 of the right Vf bin so he doesn't need a driver to keep the current to the LED from getting too high.

The driver lowers or raises the voltage from the batteries to what the LED needs at the current the driver is supplying to the LED so unless the battery voltage is close to the LED's voltage, then you should at least use a resistor(if voltage is a bit above) or a driver.

What power source will you be using?

I'm planning on using a 1 mag 3xD, and one mag 2xD, with just regular alkaline batteries.. unless there are better ways..

 

[Gunner12]

Mag3D, you can probably get away with direct drive.

2D, you'll need a driver. I can remember any drivers that will push 2 or more amps from a 2.4-3v source though.

Alkalines don't stand up to higher currents well. I'd go with rechargeable batteries but they are more expensive.

 

[ArcTec34]

hmm.. maybe I'll just make it easy then and just use 3Ds and not have to worry about all that stuff..

 

[ArcTec34]

I just bought some SSC P7s, C--J bin, so they aren't optimized for the drivers found here http://www.candlepowerforums.com/vb/showthread.php?t=195358
Besides buying buck drivers from europe, are there any other solutions? I have been searching but couldn't find anything

thanks
Brian

 

[LukeA]

I just bought some SSC P7s, C--J bin, so they aren't optimized for the drivers found here http://www.candlepowerforums.com/vb/showthread.php?t=195358
Besides buying buck drivers from europe, are there any other solutions? I have been searching but couldn't find anything

thanks
Brian

Using the AMC7135 drivers. The light will just run for less time in regulation. You won't be able to notice the change in output for a looong time though.