Sleeper Aspheric Cree 2D Thrower - Recommendations for regulator board.

[wechnivag]

Hi everyone,

I have this plastic 2D cell cheapo looking light that would be the perfect candidate for a tremendous aspheric CREE thrower. When i take this light out, I want people to take one glance and dismiss it as rubbish, and then do a double and even triple take when i switch it on! :devil::devil::devil:

Some pictures of the light and the DCX lens that i got from SS. The lens is 50mm x 30mm FL, seems good except it is not a PCX.
http://www.flickr.com/photos/24250360@N04/sets/72157604008892771/

So i have looked around around DX and all the regulator boards seem to be for 3.6V and above, for LION and RCR123 cells etc. Is there any good 1000mA 2 NiMH input regulator boards that i could use for this project?

Thanks in advance for any comments!:thanks:

 

[TigerhawkT3]

You might want to follow this thread, or you could get a couple 3AA>1D adapters to run 6AA in the 2D body and use a DX driver board.

 

[wechnivag]

Thanks, i did think about using 6AA in the 2D body, but in a 3x2 series parallel for 3.6V and longer runtime. What would be the best regulator for 3.6V in? I have trawled through DX, some of the boards are not current regulated, just resistors to vary the output voltage.

Also, any experience on using a DCX lens instead of a PCX lens? What are the differences in beam profile, if any? Since SS is out of suitable sized PCX lenses.

:thanks:

 

[TigerhawkT3]

How exactly did you plan on getting 3S2P in a 2D body? 2S3P is much easier, as you'd just use a pair of 3AA>D adapters that connect the cells in parallel instead of in series. Of course, you wouldn't have much voltage to play with.

With a good buck circuit (which KD has, I believe), you can connect more cells in series and still gain more runtime.

I have no idea about DCX/PCX. :shrug:

Have you checked out the Welcome Mat, BTW?

 

[wechnivag]

How exactly did you plan on getting 3S2P in a 2D body? 2S3P is much easier, as you'd just use a pair of 3AA>D adapters that connect the cells in parallel instead of in series. Of course, you wouldn't have much voltage to play with.

I was thinking of arranging the AA in 3 groups of 2 stacked vertically. The upper and lower group will be in line, the middle group will be rotated 90 deg and stagger overlap with the upper and lower groups. Its not the easiest thing to describe, hope you know what i mean. :thinking::thinking:

Since this is a plastic light the ID is not as tight as a D size MAG, should not be a problem fitting 4 AA diameters inside in this staggered manner. IA 2 cell driver would still be ideal as i can save the complexity and use 2 D batts.

This DX driver seems pretty good for 3 NiMH driver, decent efficiency, any comment? The feedback in the DX discussion board seems to suggest a spec change, and no clear wiring guide.
http://www.dealextreme.com/details.dx/sku.4735
What about this one? Is it Linear(resistor) or is it a Regulated driver? What is the difference? Will it give a constant current and then drop into a 'moon' mode when the batt is used up?
http://www.dealextreme.com/details.dx/sku.6190

The KD driver you linked needs at least 5V in, so i will have to use 6AA in series.

So looks like there are no good NiMH driver boards available in the market currently... All moving on to Lion batteries..

The Welcome MAT is AWESOME!!:twothumbs:twothumbs

 

[TigerhawkT3]

Linear drivers are not the same as resistors. With an LDO (Low Drop-Out), the battery needs to have a higher voltage than the LED, and the driver just dumps any voltage that is not needed to drive the LED at a particular current. With a resistor, output decreases constantly as the battery loses voltage.

I can't authoritatively state specs for DX drivers, as they change from time to time and sometimes don't have any published specs at all (that we can find), but you could probably use that 4735 driver with a pair of NiMHs, as it's been tested by users on DX with single alks and NiMHs.

I'm sorry, I can't visualize your 3S2P setup. Will the length of three AAs fit into the light's battery tube? It might be a bit much.

I don't know if I've made it clear that you can buy 3AA>D adapters in two varieties: one that arranges the three cells in series, and another that arranges them in parallel. You could use two of the former and have 6AA in series.

I'm glad you like the Welcome Mat.

 

[wechnivag]

Thought my description of the 3S2P was confusing, let me try again. :thinking::thinking:

You're thinking of the 3 pairs aligned, will not fit in the length of the 2D barrel. What i meant was to rotate the middle pair 90 degrees along the barrel axis, so if you look from the end you will see 2x2 arrangement, but staggered, with the first and the third pairs overlapping the middle pair at 90 degrees rotated. The overlap between the cell pairs should allow this to fit in the 2D length. The series parallel connection can then be done with wires soldered between the cells.

In terms of efficiency, it appears from the DX discussion reviews of some of the boards that a step up board that uses a 1 or 2 NiMH cell input is less efficient than a 3 cell or Lion input due to the voltage boost losses. Is this what the terms 'boost' - step up, and 'buck'- dump excess voltage, means? I'm probably confusing too many concepts and terms together...

So 4735 is a good board for 2 cell input, is there one for a 3 cell input too? If the efficiency gain is high enough, i might consider doing the 3s2p arrangement. :devil:

Glad to learn from you, the welcome mat is testimony to your knowledge in flashlights! :thanks:

 

[TigerhawkT3]

Ah, I believe I understand your cell arrangement. Cool. Seeing as how they'll be soldered together, I suppose you'll be using NiMHs and a pack charger?

In an LDO, Iin is the same as Iout, but with a buck circuit, Iin is actually LESS than Iout. Look in the Electrical/Electronics section of the Welcome Mat for more.

4735 should work with anywhere between one and three NiMHs in series.