A PM6 X3T @ 900mA+ off 1 X Li_Ion mod

I tinkered with an LT3436 and thought it'd be good for a decent LSV driven from 1 X Li-Ion. I had to sacrifice my last X3T I got as a spare for my MR-X from Hotbeam for this one so it hurt a bit.

The parts:

Homebrew LT3436 voltage regulated boost circuit.
PM6 host.
McModule.
1 X 17650 Li-Ion.
Clickie.
Mineral glass lens.

The results:

This chip is capable of wicked currents into an LV. Using a bench power supply set to the nominal voltage of a Li-Ion – 3.6V, I could hammer the X3T to approx 1.6A. This was found out by an accidental slip while paralleling resistors to tweak the current where the IC defaulted to it's own internal current limiting. The current drawn from the supply was 4A. Obviously way too much for decent runtime or even the health of the LED, battery and circuitry, so down it went. I settled on 900mA output current. Why? – why not? It gave reasonable current drain from the battery, reasonable runtime and great light output. I just had to have more than 750mA though.

The numbers for 900mA/3.6V input were:

Input = 3.6V, 2.05A
Output = 6.62V, 900mA
Efficiency therefore 80+%. About what's expected.

It is worth noting that the LSV did exhibit a rather large current increase with temperature. One would expect some with a voltage regulated circuit however. With the LS only mounted to the McModule, not the PM6, it got hot quick. Using my calibrated finger tip I guestimated the temp to be about 50c on the McModule at which point the current was 1A. This was still OK by me as it'll help compensate for the LS's reduced output with temp characteristics.

While I was at it, I thought I'd try one of these with a TWOK mod in the same host. Same parts as above, but with an LIII TWOK driven at 1.2A, but that's another story – btw works so great I don't know if I'll go a slightly more efficient route for a while using the TPS61030 as per others tinkering's. An extra 10% is like 40 minutes vs. 44 minutes. If I had the parts, then I would do the more efficient route for the LIII (not an option with the TPS61030 to drive an LSV).

My opinion of LVX3T at 900mA/PM6 vs.LIIITWOK at 1.2A/PM6? Get 'em both! The LIII TWOK throws a tad further and appears whiter, but there's some darkness between the sidespill at the feet and the hotspot. The X3T just gives out an almighty blast of light from the feet to way over 50m. They each have there uses. For a pocket-able flashlight either are awesome!

Yep, there's more we can do with these Luxeons. Smaller, brighter, regulated!

A few pics:





…and fits the McModule like a bum in a bucket....



If I can find the time to do beam shots, I'll add to the post.

Chris

Pics aren't working.

Pm Sent.

I'll host them untill you can fix the link /ubbthreads/images/graemlins/thumbsup.gif
I only gots cable, but your circuit is too cool to not see!

Sooo... this is what you've been doing in hiding /ubbthreads/images/graemlins/wink.gif

/ubbthreads/images/graemlins/grin.gif When's board production start?- PayPay sent! /ubbthreads/images/graemlins/grin.gif

Larry

Justin,

Thanks for that. I'll see if I can get this hosted elsewhere.

PM sent.

Hotbeam,

It was already there awaiting your stamp of approval if you had any plans. I just got bored this weekend so I did the mod. My last X3T /ubbthreads/images/graemlins/mecry.gif

Larry,

I wish. Not sure the numbers would be there for a 'real' SMT run though. Literally making the boards over the kitchen sink and hand soldering such small parts with my too large soldering iron is too much for quantity runs.

Chris

www.skywlkr.com/lights/burnt_retinas/3V_5W_boost1_soldsd.jpg

www.skywlkr.com/lights/burnt_retinas/3V_5W_boost_compsd.jpg

www.skywlkr.com/lights/burnt_retinas/3V_5W_boost_in_mod.jpg

Skywlkr,

Thanks heaps /ubbthreads/images/graemlins/bowdown.gif

We now have pics galore for all to copy from.

All,

Out of interest, what's the preference in interest between an LV vs. LIII boost? Keep in mind, the premium efficiency solution for the LIII will not power an LV so those mag boosters with an LV off 3 X NiMH's would be out. There's plenty going on out there with an efficient LIII boost, but so far no goods? Too many options out there...

Chris

I'm leaning toward doing everything with the LuxIII myself these days. I like the longer life (compared to L5), higher efficiency, lower cost, lower battery count, possible smaller size, etc. Something adjustable or at least resetable like the MR-X from say 750ma to 1200ma on this size board would be great. Adjustability is the adder needed to make a boost circuit better than DD, just being able to use CR123As or even smaller batteries doesn't really justify the trouble/expense of a booster circuit, IMO. YMMV.

My preference is to run about 850ma on low and around 1050-1100ma on high, with the 1200ma capability reserved for margin in unusual circumstances. A 20% increase in light output isn't that noticable to the eye, but the runtime reduction is apparent. I'm happy with a moderate overdrive - I can break out my MR-X when I feel like driving a real race car. But I'm all for letting everyone choose their own preferred level of insanity. Nicely done, thanks for the photos!

RussH,

Your thoughts lean towards mine hence the LIII TWOK mod in the same host. Also did an LIII DD and LIII with small resistance and I also liked very much. If you need a big gun just pull the MR-X out of the back pocket.

The LIII in the PM6 gives just enough direct light close to the feet not to take away too much night vision, yet can throw further than an X graded LED in the same host. There is an almighty blast of close up light from the LV though, perhaps most suitable to checking out the back yard at night. Different strokes for different folks though I guess, so the thought may capture someone's need.

I'll stick with the LV for a few weeks yet though and see if it grows on me. Sometimes it takes time and usage. The rechargeable option is a must for me though.

Chris