1AA minimag + Cree P4 driver question

Making a minimag shorter for my daughter and would like to drive a Cree P4 @ 750 - 1000 mA using a 1.5V AA battery.

I checked Torchboy's driver list here any the only possiblities are SS BB (no longer available) and MM+, but max output is 3.1V, so P4 will be under driven and probably not very bright. My guess is perhaps ~200 mA.

Any other possibilities? Driver diameter needs to be <17mm.

I would like to avoid 14500 since this is for my kid.

thanks!

Hill

Hill said:

Making a minimag shorter for my daughter and would like to drive a Cree P4 @ 750 - 1000 mA using a 1.5V AA battery.

I checked Torchboy's driver list here any the only possiblities are SS BB (no longer available) and MM+, but max output is 3.1V, so P4 will be under driven and probably not very bright. My guess is perhaps ~200 mA.

Any other possibilities? Driver diameter needs to be <17mm.

I would like to avoid 14500 since this is for my kid.

thanks!

Hill

Click to expand...

I don't think that the 3.1V MM+ output voltage is a hard limit. It looks like a specific limit for the Luxeon 1W LED that is referenced for that operating voltage. The boost IC used in the MM+ is configured for 5V output and can deliver up to about 1A. However, the max drive current spec (peak pulsed) for the Luxeon 1W is 500mA and that occurs at about 3.1V in for the MM+ boost IC.

The MM+ is also a voltage regulated driver, not a constant current driver, if that matters to you.

If you are willing to stick with 2xAA, then you can use a BBNG driver. I'd probably use a BBNG750 or a BBNG500 to drive the Cree P4.

Thanks for that helpful information. I have been a bit confused by this. There seems to be a shortage of available drivers for single AA applications.

Running with 2xAA gives more driver flexibility, but my host is a 1xAA cut down MM, so really limited myself here, especially since I want to stick with alkalines or NiMh.

Looks like MM+ is the best (and only) choice.

Member RV7 made a nice 1AA driver, but they were all sold, and he left (long story), At that time it was the most powerful 1AA driver around.

I think there is a version of it on DX HERE

good luck

Essexman said:

Member RV7 made a nice 1AA driver, but they were all sold, and he left (long story), At that time it was the most powerful 1AA driver around.

I think there is a version of it on DX HERE

good luck

Click to expand...

The 17mm diam is going to be a problem.

Essexman said:

Member RV7 made a nice 1AA driver, but they were all sold, and he left (long story), At that time it was the most powerful 1AA driver around.

I think there is a version of it on DX HERE

good luck

Click to expand...

Justin Case said:

The 17mm diam is going to be a problem.

Click to expand...

That particular driver came in two versions, 16mm and 17mm. Its hard to say which one you"ll get, most likely 17mm.

Both can be filed down slightly, so depending on target diameter, they might work.

One note, these drivers pull a large amount of current. They work best with NiMH or similar chemistry cells. They will kill a 1.5V Alkaline in short order, and the Alkaline chemistry won't be able to sustain the necessary current to provide full output.

-Michael

You also have to do something to the DX driver to make it a single mode. I think it was something about soldering the negative to the outer ring on top?

Thanks to all for the input. Order MM+ from SS. Will test and report back with results.

The RV7 driver looks like it would have been great. Too bad he no longer makes them.

Essexman, I may order the DX version you suggested and try that out as well.

Hill

How did your Mini Mag with the MadMax + work out? I'm looking to build a similar EDC, 1 AA Alkaline.