Prt lux III tvok direct drive on one pila 168s

[bwcaw]

I made this light more out of necessity than anyting else, but it works surprisingly well.

It has a nice, slightly greenish beam, but it is a thrower! Here are some beamshots (btw this pic is kinda greenish for some reason, the lights are NOT that green in real life)

:

The best part about this is the simplicity and the ability to use rechargeable batteries (pila 168s's). Like a fellow cpf'er said, it would be better with a L or M binned led in it though.
Here's another pic of the light next to my Arc4+:

 

[Chop]

What sort of current draw are you getting? I'm tempted to try a TVOJ and see how that works out.

 

[bwcaw]

I haven't tested it yet, this is actually my dad's light (I built it for him) so I will need to get him to let me play, er, test it. /ubbthreads/images/graemlins/grin.gif

 

[BC0311]

Well done, bwcaw! /ubbthreads/images/graemlins/thumbsup.gif Cool shots of the lights on the workbench, too.

Britt

 

[bwcaw]

Thanks Britt! BTW my dad tested it with his fluke 187 and it is drawing 930ma off of the pila at around 4v.

 

[vcal]

[ QUOTE ]
Chop said:What sort of current draw are you getting? I'm tempted to try a TVOJ and see how that works out.

[/ QUOTE ]

bwcaw-very nice craftmanship on your new light you've constructed.

Tony, I've not noticed a steady voltage on the discharge on my unknown "nekked" Li-ion AA cell. I've gone thru 10 recharge cycles on my homebuilt proprietary charger. (I read on your previous post about the voltage NOT declining during use)...(?) Does your Li-ion cell have protective features?.. -maybe that makes a difference.

Anyway, I'm very glad to discover the new 900mAh AA Li-ions now available on ebay for a measly $9.00 US for two cells! /ubbthreads/images/graemlins/cool.gif

I more or less have to use the Li-ion for now, because the post office just lost my Madmax sandwich -with a TWAK emitter-worth about $60.00!! -excrement!!!! /ubbthreads/images/graemlins/mad.gif

I won't have another 60 bucks available for a new dat2zip sandwich 'till about May. /ubbthreads/images/graemlins/frown.gifp.s.-I'm today using gadget-lover's great new little tail resistance Kroll spring in the MiniMag with good success. /ubbthreads/images/graemlins/thumbsup.gif
-see Cheers section /ubbthreads/images/graemlins/wink.gif

 

[CM]

The protection circuit puts in a very small resistance in the circuit. It's mainly governed by the FET's on resistance and is in the order of a few milli-ohms or tens of milli-ohm depending on the FET used. For DD, it may make tens of mA of difference, nothing significant. Drawback of DD is that if you do get a very low Vf LED, it will not last very long since it may get severely overdriven. DD requires matching Vf to the cell voltage. Done properly, you should get a very nice long running and long-lived LED. I'm a proponent of DD with Li-Ions since you are not wasting any power in a current limiting resistor like you would be if driving from 2x123's.

 

[Chop]

CM,
What would you call a very low Vf? Less than a K. How about a J? Now I'm being lazy. I could just go wire one up and see.

 

[bwcaw]

Actually all you need to do is check your pila's with your meter and look on the AB21 bin code chart from lumileds and match the Vf to your battery. For example: a K binned lux III's forward voltage is 3.5-3.75, a L is 3.75-3.99, a M is 3.99-4.23 etc etc.

 

[roguesw]

damn, thats a nice light /ubbthreads/images/graemlins/smile.gif
yes, i am somewhat partial to that combination,
well done on the light bwcaw
cheers
Des

 

[Klaus]

[ QUOTE ]
CM said:
I'm a proponent of DD with Li-Ions since you are not wasting any power in a current limiting resistor like you would be if driving from 2x123's.

[/ QUOTE ]

Chris,

actually I believe that a lower Vf Luxeon with some small resistance added to "simulate" a higher Vf Luxeon setting the resistance to a point where the current draw in both cases (low Vf plus resistance vs high Vf) is similar - would behave even better than the higher Vf one. The efficiency at the end of the day is similar in both cases but you get less heat builtup in the low Vf LS and the voltage drop through the resistor gets less when voltage/current drops and your brightness/time chart should get even slightly flater - we discussed something similar and I got some acknowledgement in that thread from the usual suspects (Doug, Evan) as well.

Not talking about the difference between 1xLi-Ion vs 2x123 though - I totally agree with you on that point - 1xLiIon for 3Watt and 2 LiIons for 5W in DD or sightly resistored depending on Vf is also one of my pet projects.

Just my 2 €cents and YMMV as usual

Klaus

 

[bwcaw]

What do you consider "high" and "low" Vf? I am going to build another one and have an L bin coming for that, is that a high vf or low vf?

 

[Klaus]

I would consider L to be on the high side

Klaus

 

[bwcaw]

Ok. So you are thinking running say a J or K bin with some resistance? I will have to try that.

 

[bwcaw]

BTW here is what I used for a contact instead of an ecan:

It used to be an MN01 that I cut the "stem" with the lamp off of and ran the wires through the hole in the middle. It is simple, that is probably why I can understand it /ubbthreads/images/graemlins/thinking.gif

 

[bwcaw]

Ok, just a little update here, I made another prt DD with a syol lux III in it, and the results were a lot better I think (i don't like that greenish beam of the vo bin luxeons) Here's a pic of them side by side with the arc 4 for reference:

 

[Reno]

bwcaw, any chance I could fund a creation like that syol PR-T? I'll even send you my E2e's LA for "re-education"

 

[Justintoxicated]

The S bin lux looks WAY brighter than the T bin lux...What gives? I know my S-bins SX1J's were pretty bright, but I don't have any T-Binned lights to put it up against...not yet anyways

 

[bwcaw]

I am not sure why that s bin looks brighter than the t bin. It is wierd. Those might not be T bin leds after all. I got them from a fellow cpf'er as bare emitters, so I may have heard wrong or something, maybe they are svoks? Or maybe the camera just picks up the blue light better. (to my eyes they are about the same brightness only the syol is bluer)