Heat from SSC P7

[Umibuta]

Does anyone have any knowledge on the heat from the P7? I am in the midst of building a light using a Maglite 3D.

1) Will the heat from a (or max 3) P7 be too hot on the lense?

2) Does it has the same problems as filament bulbs where using it on land will deform the lense?

I will be using a heat sink for the P7 itself but i am more worried about the effect of heat on the lense.

Thanks in advance.

 

[Packhorse]

Its not a problem.
The heat from LEDs mostly comes out the back (eg heat sink).
3 may be a different story though. But then I doubt you would want to run 3 P7's at full power out of the water any way. 1 is pretty bright.


I had a 35w Halogen mag dive light that got turned on with out me noticing on land. When I found it the 3.6mm acrylic lens has softened and the pressure in the light head and increased with the heat. Result was a convex lens! I thought it was quite cool and told everyone I did it to get a higher depth rtating!

 

[Umibuta]

Thanks Packhorse.

I intend to use the lights for video though I am not sure if 2 lights of a single P7 each would be sufficient.

There are various methods of sealing the maglite and I thought the method on this would suite me best. As noted by the author heat possibly contributed to the seal failure. Being a filament bulb (this is half a decade ago), I wonder if P7 (or LEDs today) would pose similar problem.

 

[Packhorse]

I just change all the O rings for the biggest that will fit ( search some of my threads for exact sizes) cut the handle for the desired legnth and epoxy it it. Replace lens with a thicker one.
Good to at least 57 meters so far. Done 7 or 8 and no leaks.

 

[Umibuta]

I am actually a long time lurker and I have also read your posts on SODs. I have been procrastinating till now to build my 1st light.

I have got a 5mm thick Acrylic lense stepped (4mm) to fit the Mag. I guess that should be enough for at least 60m. I will start another thread to discuss my process before I go OT on my own thread

Do you have any idea how hot it gets in front of the LED at 2.8A? I am not too worried about the back as I will heatsink it with contact to the Mag barrel ..... somehow.

I assume you heat sink your drivers too? How do you do that?

 

[Fulgeo]

I am actually a long time lurker and I have also read your posts on SODs. I have been procrastinating till now to build my 1st light.

I have got a 5mm thick Acrylic lense stepped (4mm) to fit the Mag. I guess that should be enough for at least 60m. I will start another thread to discuss my process before I go OT on my own thread

Do you have any idea how hot it gets in front of the LED at 2.8A? I am not too worried about the back as I will heatsink it with contact to the Mag barrel ..... somehow.

I assume you heat sink your drivers too? How do you do that?

I have driven a P7 at 2.5-2.8 amps using 2 parallel 4xAMC7135 drivers for hours at a time on my night stand. I use 3 Accupower 10,000 mAh D cells as the power source. It does get warm but not hot. Still comfortable to hold. This is standalone. On a long walk were the flashlight is in your hand and your are part of the heatsink it is just slightly warm not much more than skin temperature. On my build as long as the supply is under 4.2 volts heat is not an issue emitter or driver wise. If you are using a single lithium ion cells or lithium ion cells are in parallel you will be 4.2 volts or under so you should be fine if you are using AMC7135 based drivers. You can heatsink your drivers by attaching them to the emitter heatsink. You can also use some "shark fins" to attach them to the body of the flashlight. Here is third method. Buy some copper pipe with a diameter a little bigger than the inside diameter of your flashlight. Cut it down to 1 inch length. Cut a small section out of the side of the pipe. Now it is springy and can be fit inside the body of the flashlight. Now make two parallel partial cuts down the length of tube about the width of your driver. You want to be able to bend this little platform down perpendicular to the inside of the copper pipe if you follow me. Flatten out this piece of copper so you can attach your driver to it with thermal epoxy. Also remember you want to have a spot of epoxy on each AMC7135 chip. Put a little dab of thermal paste on the copper heat sink sleeve you have made when you finally assemble your build. Since this is a dive light you will have no problem with heat. I would doubt it would even get warm since the whole body of water you will be in will be your heat sink. Happy Mods!

 

[Fluor]

I made a Quad P7 divelight some time ago. It gets too hot to be used on land. Im gessing i can run it for 20min or so with out overheating it(maybe more). The heatsink reaches 54,4degC in 20degC water after a while. The LED might get damaged if it exceeds 70 degC.

See build:
http://www.candlepowerforums.com/vb/showthread.php?t=213694