Need driver help please

[flip]

I am a bumbling idiot with electronic stuff so if the following makes no sense, please tell me, I won't be offended.

I have a couple of these emitters: Osram Ostar LEW-E3B PX-7L. I want to make a P60 style drop in and or mod a light for these. I would prefer to run off of 1x18650 so I need a boost circuit.

What driver do I need and where do I find it?

Or...would these be good to use in an automotive LED fog light and run direct drive?

The seller provided this info for me:

PDF


looks like 20.8V Typ. Vf @700ma


450-520 Lumens


and a 7L tint

 

[HarryN]

Hi, interesting and aggressive project. Perhaps I can save you some time.

24 volts x 700 ma is around 18 watts draw from the driver and battery setup.

18650 cell pulling 18 watts = 3 volts x (x) amps. Amps = 6 - 7amps. That is a LOT - possibly at the very edge of the batter capacity, if not past it.

Boost drivers are designed based on the ratio of input to output boost. 3 volts in to 24 volts out. To be sure it would work, it would have to be capable of pulling from 3 volts max, so 24:3 = 8:1. That is nearly 2x the boost of most drivers on the market, outside of perhaps something from taskled. The taskled drivers for boost don't work down to that low of voltage.

I have done some work on a boost driver in that general power range, but it is a lot bigger than p60 size.

In other words, maybe start with a different project first. Edit - perhaps try a different host light. Example, a 2D size light with an 8AA to 2D adapter would get you to around 10 volts under load. That is more in the range of available boost drivers.

 

[350xfire]

Why use the Ostar... Those things are dead to most people! Cree XML, MCE, SSC P7, SST 50, 90 etc can beat the Ostars of yesterday for much less $$$.

 

[HarryN]

He already has the ostar's, so it makes sense to use them if possible.

 

[flip]

Thanks guys. I appreciate your input.

So, I guess I will have to come up with a plan...C or D. Maybe a M@g with some lithium cells or mod an existing light that takes a few batteries...

If anyone has any suggestions on what to try, please speak up.

Thanks again guys.

 

[Lumencraft (Matt)]

Hey flip,

There is no way your gonna be able to run one off only 3.7V and get any decent output. The closest you could probly get is to use a blue shark with 2x li-ion. I have done this in a surefire KL4. It important to heat sink the blue shark well though. It will be far easier on the driver if you go to 3x li-ion though. The driver doesn't have to work so hard then and its less likely to overheat and kick to low.

I would say of the ideas you mentioned for using them the fog light thing or an existing fixed focus host would be your best bet. Using these in a mag means making a custom heat sink, and a huge bore in the reflector if you want it to remain focusable.

I will say these are pretty bad when you fire them through an ashperical though.

 

[flip]

Thanks a bunch!