Here we go again!

Packhorse · **Posted:** Sun Feb 08, 2009 9:54 pm

clayhwalker wrote:

Have you tried to use a single 52mm aspheric lens instead of 4 individual ones? I didn't know if the aspheric would culminate the light or not.

As I said in the PM it will not work.

MikeB · **Posted:** Tue Feb 17, 2009 11:41 am

Hi Packhorse

I have a few further questions relating to the driver and LED setup.
What type of batteries and what total voltage are you currently using?
Have you wired the all LED's in series?
Does AMC7135 driver which you are using have any low battery warnings or protection?

I am wanting to build a similar setup using 4 Q5's but I really am not sure about the driver. I would like to drive them at 1400mA, 3.7 - 4 Volts. This means I will need a total output between 14.8 - 16 volts from the driver. Would it be best to use a buck driver similar to this:

http://www.pcmus.com/Dive-Photos/LED-Genie.htm

From what I have read the buck drivers do not get as hot and have greater efficiency than the boost-buck drivers. Do you know much about this?

Packhorse · **Posted:** Tue Feb 17, 2009 12:19 pm

You really need to stop using that invisible ink MikeB!!

I use 8 NiCD cells in serries so it 9.6 volt.
The AMC 7135 is nothing more than a smart resistor that burns off excess voltage as heat. If the Vin is less than the Vf then the AMC 7135 lets all the current flow where a resistor will still burn off XX% of the voltage.
I am not using the AMC7135 driver in this but the Kai Domain 2.8a P7 driver which has low volt warning @6v+-

You could run all LEDs in serries and it may be better to do it this way but you will need 16v +.
Im not expert in drivers but I think the best one to use really depends on the LED configuration and battery pack choice.

treedog · **Joined:** Thu Jul 16, 2009 1:12 am **Posts:** 9

Wow, very informative thread! I noticed that your custom heatsink transfers heat over an area in the head and also into the handle. Most of the "drop in" heatsinks out there only transfer heat to the head. Is your heatsink overkill or does it really have to be that large? How hot does the flashlight get when underwater?

I was planning on using 3 Cree XRE Q5's running at "only" 700mA each but was going to use an aluminum disc that is about 3mm thick (diameter large enough to touch the head along the circumference). Do you think that would be enough heatsinking?

Packhorse · **Posted:** Thu Jul 30, 2009 10:40 am

Its overkill for use in water. Out of water its sufficient
The circumstance will not transfer much heat but if the rear of the plate contacts the rear flat part of the head it will be fine.

treedog · **Joined:** Thu Jul 16, 2009 1:12 am **Posts:** 9

hmm...so you don't think just a 3mm thick aluminum disc touching the head by it's circumference only would be adequate for 3 XRE's at 700? it would have to extend down to the flat part in your opinion?

btw, thank you again for all your input. Very much appreciated

Packhorse · **Posted:** Thu Jul 30, 2009 1:52 pm

The question is how much of the circumference will be in contact with the maglite head. If its not perfectly machined then it will only be a 3mm line 0.1mm wide at best.

Anyway depending on the optics you use the plate will not have to be much thicker than 3mm anyway.

What driver and optics are you thinking of using?

ChillyWilly · **Joined:** Fri Aug 07, 2009 4:27 am **Posts:** 2

Packhorse,

New member here, i really like your build. I currently have a P7 moded mag and i works great, I want a more narrow beam.

Anyway, i noticed that you used the P7 2.8a driver on these Q5's, how did you wire the Q5, 2 series and 2 parralel?

Also the PVC spacer that you used on the aspherics, is it 4 pieces of pvc pipe, what size?

Thanks,

Packhorse · **Posted:** Fri Aug 07, 2009 8:12 am

Nice set up!
My own set up uses a 2P2S set up of the Q5 leds so each runs at 1400ma. This is way over driven so the ones I sell are driven 4 parallel and they get 700ma each. The 2P2S set up consumes twice the power and produces about 50% more light.

The spacers and lenses take a bit of work to make and you really need a lathe to do it. ID or the PVC is about 16mm from memory and the OD needs to be machined down to 17mm. Aspheric lens diameter is 21mm and these also need to be machined down to 17mm to fit 4 in a maglite.

clayhwalker · **Joined:** Tue Dec 16, 2008 9:28 am **Posts:** 4

Did you just put on a resistor coming off the P7 driver to reduce it down to 700ma or did you find another driver?

Packhorse · **Posted:** Mon Aug 17, 2009 9:24 am

2800ma / 4 emitters in parallel = 700ma each.

ChillyWilly · **Joined:** Fri Aug 07, 2009 4:27 am **Posts:** 2

Packhorse wrote:

Nice set up!
My own set up uses a 2P2S set up of the Q5 leds so each runs at 1400ma. This is way over driven so the ones I sell are driven 4 parallel and they get 700ma each. The 2P2S set up consumes twice the power and produces about 50% more light.

The spacers and lenses take a bit of work to make and you really need a lathe to do it. ID or the PVC is about 16mm from memory and the OD needs to be machined down to 17mm. Aspheric lens diameter is 21mm and these also need to be machined down to 17mm to fit 4 in a maglite.

Thanks for the Reply Packhorse !

It's a lot of fun to build these lights, I'm actually working on getting a Mini Lathe so I can start making my own lightheads.
When you overdrive the Q5, how's the heat production, have you had any issues with damaging the Q5's due to the higher current.

I'm just gona start playing around with aspherics, so should be fun.

Keep up the good work !!

Packhorse · **Posted:** Sat Aug 29, 2009 12:37 pm

No issues at all. I can run my can light out of the water for as long as I want. Although I use a large heat sink that does slip inside the handle and conducts very well with the maglite itself.

I dont see any benefit running them over 1400ma though.

Here we go again!

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