3x 18650 10W HID lights?

[Xe54]

Hi:

I have a modified 2D cell mag light with 10W WA HID system "Mag HID" which uses 8xAA NiMH cells for power. I think I bought it from 4sevens or Ra here on CPF.

I am interested in modding it to run on 3x 18650 Li-ion cells. This could shorten the length of the light, make it lighter, and possibly improve the ability to acheive full run times without worry of reversing NiMH cells, a problem I have had and which is particularly hard to avoid when using 8 cells.

Another mod I'd like to try is sawing off the outer envelope of the 10W HID bulb. There was another poster who custom built a nice small 3x 18650 HID light, and used the bare HID burner together with a specially selected reflector. That poster asserted that the envelope around the arc translates the rays depending on angle, so that it is impossible to get the best throwing performance. I am convinced this makes sense so would like to try the light with a bare burner. I have the means to mod the bulb myself.

However, this would mean that a smaller hole in the reflector would be feasible as well. So I'd like to consider getting another reflector.

Are there any 3x 18650 commercial lights? It seems like this would lead to the ideally small size for a 10W rig.

 

[MikeLip]

Another mod I'd like to try is sawing off the outer envelope of the 10W HID bulb. There was another poster who custom built a nice small 3x 18650 HID light, and used the bare HID burner together with a specially selected reflector. That poster asserted that the envelope around the arc translates the rays depending on angle, so that it is impossible to get the best throwing performance. I am convinced this makes sense so would like to try the light with a bare burner. I have the means to mod the bulb myself.

I'm not entirely sure this is a good idea unless you've thought it through. Doesn't the outer envelope of the lamp absorb the UV, which these guys tend to put out a lot of? You'd have to substitute for that somehow, otherwise you could do yourself some damage.

 

[cmacclel]

The outer envelope on the Welch Allyn 10W Solarc lamp is just clear Glass with a frosted top. If it blocks UV it would supprise me.

As for 3x18650 they would have to be end to end as they are to wide to fit together. Even with 17mm cells the light needs to be tri-bored.

Mac

 

[Xe54]

I'm not entirely sure this is a good idea unless you've thought it through. Doesn't the outer envelope of the lamp absorb the UV, which these guys tend to put out a lot of? You'd have to substitute for that somehow, otherwise you could do yourself some damage.

Don't worry--I've thought it through. The UV will be blocked by the lens over the flashlight aperture, provided it's the right kind of glass. I can test this.

 

[Ra]

Hi Xe54,

The poster you refer to was me!

For better throw, it indeed is better to remove the protective bulb. Don't worry about the UV-radiation: The ingredients within the bulb cause the optimal emission to be in the visible part of the spectrum.

You can see the spectrum of the bare bulb in the review I posted about the Eznite 10 HID:

http://www.candlepowerforums.com/vb/showthread.php?t=168608

The thread about my own 10watt HID creation:

http://www.candlepowerforums.com/vb/showthread.php?t=126565

Ealier, Welch Allyn made the 10watt bulb without the protective bulb around it. But that way, the bulb seemed to be too fragile for most applications, so a few years later, they decided to protect the inner bulb with an outer bulb..

In my 10watt mini-HID monster thread, you can read about "optical arc dissplacement", caused by the outer bulb. However, to solve this problem, you not only need to remove the outer bulb, you need a high quality, parabolic reflector as well!
On top of that, you need to exactly position the bulb in the reflector, and fix it there, or create a sideways x-y collimation possibillity on the bulb like the EZnite.

I'm talking about positioning the bulb within 0.05 millimetres !

With the protective bulb removed, you still need quite a big center hole in your reflector (+8mm diameter), because the return-wire on top of the bulb goes out widely sideways..


Hope this helps..



Regards,

Ra.

 

[Xe54]

Hi Xe54,
The poster you refer to was me!
For better throw, it indeed is better to remove the protective bulb. Don't worry about the UV-radiation: The ingredients within the bulb cause the optimal emission to be in the visible part of the spectrum.
You can see the spectrum of the bare bulb in the review I posted about the Eznite 10 HID:
http://www.candlepowerforums.com/vb/showthread.php?t=168608
The thread about my own 10watt HID creation:
http://www.candlepowerforums.com/vb/showthread.php?t=126565
Ealier, Welch Allyn made the 10watt bulb without the protective bulb around it. But that way, the bulb seemed to be too fragile for most applications, so a few years later, they decided to protect the inner bulb with an outer bulb..
In my 10watt mini-HID monster thread, you can read about "optical arc dissplacement", caused by the outer bulb. However, to solve this problem, you not only need to remove the outer bulb, you need a high quality, parabolic reflector as well!
On top of that, you need to exactly position the bulb in the reflector, and fix it there, or create a sideways x-y collimation possibillity on the bulb like the EZnite.
I'm talking about positioning the bulb within 0.05 millimetres !
With the protective bulb removed, you still need quite a big center hole in your reflector (+8mm diameter), because the return-wire on top of the bulb goes out widely sideways..
Ra.

Hi Ra. The EZnite is cool. I had often thought about XY and Z axis alignment for a HID flashlight. At work I built some illuminators based on D2S bulbs run off special DC ballasts (DC arc current, for no flicker in high-speed videography). I used Thor Labs mirror mounts modified by a machinist to have a bulb mounting adapter. The mounts allowed the bulbs to be adjusted XYZ.

However, the "bowing" of the arc due to internal convection currents really makes it impossible to get all of the light into collimation. Like you say, you can basically only get an electrode hotspot located at the paraboloid focus.

Of course, paraboloid accuracy is also important. I used crappy Carley reflectors. Just visual inspection revealed poor surface curve accuracy. I got interested in talking to machinists about programming paraboloids on a CNC machine, then the project became less important.

Oh, and we bought a 100W 50kHz rep-rate 532nm laser to do the videography!

BTW, how did you machine the glass reflector?

P.S. Ra, you know that the term "surface brightness" really doesn't convey any different information than the official term of "luminance" with units: (cd/m^2). Why don't you just use the term luminance?

For a HID arc, it is quite difficult to quantify the luminance, because the arc is not a solid emitting surface but rather an emitting volume with varying luminance depending on the surface area chosen as the "effective" surface area/volume of the arc. At a distance, it is sufficient to consider the arc a point and characterize it in terms of luminous intensity (candela) as a function of angle. But up close where the arc can't be considered a point, the task of a reflector designer is much more complex and cd vs. angle data is not enough. I had thought about this problem to some degree when I spent some time studying photometry/radiometry, but didn't pursue it in depth. I was more interested in CIE color. Besides, electronics is my main field...