Flash only led driver.

I'm working on a custom bike light for the wife and me. I've got the front end almost figured out, but I want the rear flashers powered off the same setup (only one battery pack to charge).
I'll be running 3 triple XP-E stars for each tail light. I plan to run them at full power during the day and about 1/4 power (or a little less) during the night. Drivers here in Spokane are stupid and don't look for ANYTHING, so I don't want to give them any chance to miss us.

What I am looking for is an led driver that can operate off of a 6s or 4s2p pack and will go straight to a flash mode when power is applied. All the drivers I've seen want you to have to step through different modes to get to a flashing mode.
Also, anyone happen to see a triple star led housing that has the three stars in a row (instead of a triangle)?
-PBB

BobBarker said:

....... Drivers here in Spokane are stupid and don't look for ANYTHING, so I don't want to give them any chance to miss us.
-PBB

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Ahhhh, so you have that problem too!

Since you are doing a custom setup, have you considered designing your own driver?

Yeah, I know that I may have to end up making my own driver... But I figured I'd ask if anyone knew of one, before I went through the hassle of making one myself.
Still looking for the holder though... I know I've seen it, just don't remember where. It looked like 3 circles in a line and attached. I may have to make my own of that too :/
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BobBarker said:

Yeah, I know that I may have to end up making my own driver... But I figured I'd ask if anyone knew of one, before I went through the hassle of making one myself.
Still looking for the holder though... I know I've seen it, just don't remember where. It looked like 3 circles in a line and attached. I may have to make my own of that too :/
PBB

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Is a 4P battery out of the question? Going with a linear regulator simplifies things considerably. White led's behind red lenses, or red led's behind a clear lenses?

Well, the tail light is only part of it.
The battery pack will be running a headlight with 3 XM-L2s (two in 105*13 degree lenses and one in an 8 degree) and a few others (that I haven't decided on, but I'm leaning on a pair of 3-Up Cree XP-G2 Stars that will be bare with a protective cover) facing down as fill lights, and 3 3-Up Red Cree XP-E Stars for the tail light. I want the pack to power all of them, so I don't have to worry about multiple backs or primary cells. I can just take the pack off at the end of the ride, and charge it.
All of these (except the tail light, and battery pack) will be mounted in a 4 1/2" 6160 rod that will be finned in all areas that allow it (from the front optically clear plexy to the back), and mounted to the head tube. This seems like the best solution, considering that neither my wife nor I want the light mounted to the handle bar. We also have helmet mounted lights that are rated at about 200 lumens. That will give us about 4500 lumens (that I can always turn down it it ends up being too much) of white light plus the helmet mounted lights + the 60 on my G29SF if we "really" need it.


I'm planning on having a total of 3 modes.
Mode 1=(riding mode) All XM-L2s at full power, 3-up stars at 700mA, tail light at 1/4-1/3 power
Mode 2=(passing mode) spot light off, wide angle lights run at .350mA each and lower fill at 700 mA, and tail at 1/4-1/3 power
Mode 3= (day mode) white lights off, tail light at full power

The control between mode 1 and mode 2 will be a push button on the right or left hand above the shift lever.
The control between mode 1/2 and off and mode 3 will be on a 3 way switch located somewhere on the frame (or battery pack).

The reason that I won't do a 4p pack it that the XM-L2s run at or around 3.35v at 3A, so I would need a buck/boost driver to get full output after the first hour of the ride. Running a 4-6s pack I would lose at most 15% driver efficiency (in buck mode), but gain quite a bit more usable pack life. If I went that route I would need to be drawing 10-14 amps (+ driver losses), so I would also need to be running 12-14ga for the battery/switch/light connections. As far as I can tell the dual mode driver cost quite a lot more and I really wouldn't be gaining anything by going that route, but you didn't have the full picture at the time so I can understand you recommending it.

-BB

The reason I asked about the 4P solution is that I have a multi channel linear master/slave setup that would have been able to handle the 3x3 XP-E's in a 3(3 x 1A) configuration. The fact that you are going to use red XP-E's makes for worst case scenario on the linear regulators, so that is definitely not going to work very efficiently.

Sounds like an interesting build, and the best of luck.