ZebraLight AA, Nimh 550 Lumen Boost Driver?

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moderator007
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ZebraLight AA, Nimh 550 Lumen Boost Driver?

ZebraLights SC5w Mkll can do 550 lumens from a xp-l2 using a AA, Nimh cell. According to TA's test here with the xp-l2 that should be about 1.25 amps to the led which should be slightly above double that on the input side of the driver. I have searched many times for a boost IC from a single AA, Nimh cell but I have never found anything that even gets close to the output of 1.25 amps. Does anyone know of a IC that can do this or maybe even seen the circuit of the driver? Any info would be helpful!

Edited by: moderator007 on 05/20/2020 - 20:13
iamlucky13
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We discussed this topic a bit at the other forum when the mk II AA-powered lights were new. A member received an answer from Zebralight explaining that the boost circuit of the SC5 II uses 4 inductors to share the work of boosting the voltage and provide relatively high amperage.

I doubt any manufacturer other than Zebralight has put the electrical engineering effort into getting that much output from a single NiMH cell.

Bob_McBob also documented that the H53 and SC53 each only have a single inductor, consistent with Zebralight’s distinction between those drivers and that of the SC5, and with their lower maximum output.

I don’t think he’s modded an SC5 II so far.

Also, I don’t think anyone has so far measured output numbers quite in line with Zebralight’s claims, so it might not really be 550 lumens.

moderator007
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That pretty much answers my question, I was going to try to couple together a couple of PAM2803’s to see if it would actually work.
That’s how they are doing it, I just dont know the IC used or if there’s alot more going on I don’t know about.
I’ll test to see what coupling two together does excatly.
Anyone had a SC5 apart that might know the IC’s used or if they sanded the markings off?

loneoceans
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moderator007 wrote:
That pretty much answers my question, I was going to try to couple together a couple of PAM2803's to see if it would actually work. That's how they are doing it, I just dont know the IC used or if there's alot more going on I don't know about. I'll test to see what coupling two together does excatly. Anyone had a SC5 apart that might know the IC's used or if they sanded the markings off?

There are a few ways to do this; here is one (not really cost optimized) example: https://www.analog.com/media/en/technical-documentation/data-sheets/3425f.pdf.

www.loneoceans.com/labs/

lume1 - Constant Current BuckBoost + FET Anduril Driver for FW3x
High Power Boost Drivers - GXB100 100W GAN FET Driver // GXB172 50W 17mm Driver
GXF22 - CC+FET for Emisar D4 // GFS16 - 1milliOhm FET Switch System // Older: GXB17 & GXB20

moderator007
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That maybe the IC they use. Apparently they’re using 4 inductors and that IC rquires 4 inductors to run in 4 phase boost.
From the example layout of a pcb in the datasheet it looks like getting this down to a 17mm or smaller 2 sided board might be possible.
I looked and looked for something similar to this and you just pop in and lay it in my lap. Thumbs Up
.
If you think you might consider another driver project, I vote for this one. Thumbs Up Big Smile
It be awesome to have some of these small AA lights pushing 2 amps or more from a single Nimh cell with a driver swap.
I would be one of the first to build one.

sidehack
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My cousin just asked me two days ago about a single-AA-sized light. Might be worth looking into.