Boost Circuit

[Justintoxicated]

Man, I'm having a tuff time trying to decide.

Sounds like my best bet would be either a 3C (with NIMH rechargables?) and your circuit.

or

2C with 3x123.

And in either case after spending that much money I would also want a T or U binned lux III? right?

 

[Burnt_Retinas]

You can always mod the host of your choice with the circuit/s of choice and make do with the LED's available. When the LED of choice becomes available, just swap the LED.

Chris

 

[cy]

[ QUOTE ]
Burnt_Retinas said:Cy,Re PR head/123's - No on the 123's. A direct drive may do the trick for high currents. A boost with 2 X 123's will be almost direct drive anyway for an LIII (I assume you were referring to an LIII). It is not a config that needs a boost. A downboy perhaps?

[/ QUOTE ]

Is your proto board setup to drive from singe 123 to output 1.2 amps? What is the max amps your getting from single 123 and the runtimes?

My PR is running a 5watt BB750 w/vf 6.5 Volts 2x 123, way underdriven. I'd like to construct a 5 watt 1.2 amp sammie and convert a PR head to accept sammies. I'm spoiled by firefly's modular sammie design.

Running 5 watt lux w/BB board allow you to run single 123 or two 123. My plans are to custom a BB to 1200 milliamps to make up a sammie. I saw your notes on a 1.2 amp proto board and was quite interested in your feedback.

Thanks,
CY

 

[shiftd]

5W at 750 mA is overdriven, not underdriven, but that is according to lumileds.
while I agree with you regarding the 5W being not enuff driven at 750 mA, i thought i better straighten things up /ubbthreads/images/graemlins/smile.gif

 

[Justintoxicated]

Ok, while I really wanted a 2C host with a Boost circuit, I'm about to give up on the idea all together /ubbthreads/images/graemlins/frown.gif

I noticed those Pila batteries would probably work PERFECT for a 2C host and a 5 watt Lux, and your boost circuit....

However that $100 for the batteries ALONE, that is just way over my budget /ubbthreads/images/graemlins/frown.gif I wish Pilas were a little cheaper so I could actually use them, but $100 just for 2 batteries and a charger is too much....

So then the idea of using 3x123 in a 2C and your circuit and a Lux III comes to mind...What do you think of this setup? I may start on this over spring break...PM me how much you want for the prototype board.

So now it is between NIMH 3C and 3x123 2C....Any comments?

 

[Burnt_Retinas]

cy,

You'd hit another brick wall trying to boost from a single 123 to drive a 5W > 750mA. The 123's can't output enough current, at least not for long at all, perhaps seconds to a few minutes.

*edit* The use of a single Pila is a different story for a PM6. I have tested the circuit with 1 X Li-Ion (not Pila) and it'll nicely boost >800mA. I did not take it further, but on numbers alone it should be capable of >1A. How far is unknown. The BB's still surprise me so who knows. May have to thrash the circuit from 1 X Li-Ion into a 5W?

Justindetox,

If you wanted 3 X 123's to drive an LIII you'd need a buck converter, not a boost as is the circuit I have. Just so happens I made a thrasher of a buck to waaaay overdrive a LIII (to see what can be done). Maybe a similar set-up would be perfect for a 3 X 123 LIII mod. Check here

Note, I'd do it differently in hindsight if I needed to again. It'd be similar to the MadMax - voltage regulated. It'd be a LOT smaller. What you want can be done. I guess that's the point of the exercise.

Note also, pics didn't show the last time I tried. I think it's CPF that may be problem. Try selecting properties of pic, copy URL, open new window, paste into addy and they should show (IE).

Chris

 

[Justintoxicated]

How does your circuit compare with a BB? More or less efficient?

I take it that it will work in either a 2C or 3C? I know I can DD a 3C but will your circuit keep the power boosted.

I have been thinking about batteries...I'm probably going to go with NIMH, for now anyways...

Let me know!

Im trying to decide between the following 3 lights

2C NIMH x Lux III (Try to get a T-bin)
2C NIMH x Lux V (Try to get a T-bin)
3C NIMH x Lux III (Try to get a T-bin)
3C NIMH x Lux V (Try to get X-bin)

Your opinion? I'd prefer a 2C platform but im not sure I could drive a lux V on 2 NIMH C's???? Good Bin Luxeons are scarce right now, so I'd grab either a T bin Lux III or a X bin Lux V (If I can ever find one).

I'd like to get started on the platform soon though

I could not get any of your pics to work at all.

Are Cyan Lux III's brighter than white ones?

 

[Burnt_Retinas]

The circuit I did is intended to boost 1 X Li-Ion (= 3 X NiMH's in voltage) to drive an LV at decent current. It's efficiency is probably about the same as BB. I don't have a BB to compare, but a BB won't drive a LV at decent current (>rated) from less than about 4V from information I have gained, this circuit will. I'm guessing on BB performance here.

The circuit I have is not suitable for 2 X C NiMH. A 3 C NiMH is OK.

An LIII can be driven from 2 X NiMH from a BadBoy quite nicely, but don't expect 1A, perhaps less.

Of your choices,

Others will differ. It's a case of different strokes for different folks:

2C NIMH x Lux III (Try to get a T-bin) >> Average performance (MadMax).

2C NIMH x Lux V (Try to get a T-bin) >> VERY average performance, no circuit recommendations.

3C NIMH x Lux III (Try to get a T-bin) >> Now you're talking. Bright spot, the best throw. Up to 2 A possible (circuit I have), or BB/MM for average current/brightness.

3C NIMH x Lux V (Try to get X-bin) >> Again, now you're talking. Perhaps over 1 A (circuit I have), or BB for 700mA odd down to battery voltage of about 4V, dropping from there.

Given you're probably talking a Mag, I'd personally go the 3C NiMH x Lux V boosted (regulated) to anything over 1A from NiMH. This of course will debated depending on size/weight/performance etc. It would be be my personal choice though from those suggested for a distance throwing flashlight. A PM6 mod for closer illumination.

Note, you can DD an LV from 3 X Li, in fact a 2C, but then you'd *only* have an a Space Needle. It's OK as it's simple to do, cheap, but non-recargeable. I use my flashlight quite a bit so a 123 config is a no-go, otherwise I'd have gone a Mr Bulk SNII config. A damn nice light in it's time....until electronics finally caught up with it.

Note, for an LIII solution at better efficiency, try Jarheads solution in his efficiency post. I don't have samples of similar chips to tinker with just yet.

Chris

 

[RussH]

IMO, the T bin is too low of forward voltage for direct drive on 3C (NiMH or alkaline). It doesn't make since to add a regulator and waste 20% of your power - plus you would then need an even higher voltage to compensate for the regulator voltage drop. I built a 3D lux3 and a 3C lux3 using, IIRC, an SWAK. Don't get me wrong here, the boost does make sense with 2 cells and could be used with 3 cells, especially if you wanted to drain alkalines to death & maintain light output.

The D cell light draws about 1000ma on NiMH Ds and the C cell light draws about 1200ma. Throw and spill is just barely different between these two lights. I don't think there is an observable difference in overall brightness. IMHO, going over 1200ma. doesn't increase the light output. I don't see any difference in 840ma. in one FT-3C and about 1.5amps in another FT-3C. In fact, when the second one gets hot, there may be even less lumens overall.

The K bin Vf is just about ideal with NiMH or alkaline. In fact, you might regard the NiMH as self regulating for about 90% of run time without any regulator. The voltage only drops about .1v (that's about 8%) thru 90% of the batteries discharge. The change in light output with that small a change is not really noticable.

-RussH

 

[Justintoxicated]

[ QUOTE ]
RussH said:
IMO, the T bin is too low of forward voltage for direct drive on 3C (NiMH or alkaline). It doesn't make since to add a regulator and waste 20% of your power - plus you would then need an even higher voltage to compensate for the regulator voltage drop. I built a 3D lux3 and a 3C lux3 using, IIRC, an SWAK. Don't get me wrong here, the boost does make sense with 2 cells and could be used with 3 cells, especially if you wanted to drain alkalines to death & maintain light output.

The D cell light draws about 1000ma on NiMH Ds and the C cell light draws about 1200ma. Throw and spill is just barely different between these two lights. I don't think there is an observable difference in overall brightness. IMHO, going over 1200ma. doesn't increase the light output. I don't see any difference in 840ma. in one FT-3C and about 1.5amps in another FT-3C. In fact, when the second one gets hot, there may be even less lumens overall.

The K bin Vf is just about ideal with NiMH or alkaline. In fact, you might regard the NiMH as self regulating for about 90% of run time without any regulator. The voltage only drops about .1v (that's about 8%) thru 90% of the batteries discharge. The change in light output with that small a change is not really noticable.

-RussH

[/ QUOTE ]

I have not had any problems Driving my SX1J light DD off 3C with the hotlips HS...Honestly it does not get that hot...The T bin is brightness only, you can easily get a TX1J which is just a brighter emitter. I find the J bin is useful on a DD light in that it uses less power so it last longer...Although it may not be good for the LED durring the first 20 minutes...Well Oh Well!

You bring up a good point about boosting voltage from 3C NIMH Batteries, it really is almost not necessary, Unless you want the light to run at its full potential for it's entire runtime. As I understand it 3 NIMH will only put out 3.6-3.8V Im not sure how much current the light will draw at this voltage.

I was hoping to be able to run a Lux III off 2C NIMH @ 1 amp or a Lux V off 3 C NIMH at 1 amp....

The problem I have with direct driving is I always want to put in fresh batteries even when it is down to 800ma. I can tell a difference!

I think I may be building a regulated 3C NIMH with a Cyan Lux III...Should look like a huge laser out in the middle of the dusty desert!

Burnt, I could swear you could pull an amp from 2C NIMH to drive a lux III? But if you strongly recomend building another identical (only regulated) 3C Mag conversion I will go that route and use your circuit. a 750ma version does not sound appealing at all, I'll have a VIP for that soon enough...

I looked into Jarheads desuigns and decided I do not have enough free time right now to tinker with that circuit. Perhaps in the future I will have mroe free time as it is very interestnig. I also have no idea where to get the part he is using...

Your circuit is Current regulated correct?

I have some time to order a 3C mag (I don't want another blackone and thats all I can find around here) Sinch there does nto seem to be many good Lux III Whites untill April...I'll probably use a cyan anyways But I prefer to order in larger quantities to avoid shipping charges.

 

[Burnt_Retinas]

RussH,

They're all true and fair comments. It's a case of different strokes for different folks. Yes, DD works fine, but juggling bin ratings and knowing you have the full brightness right till the batteries are dead makes a difference to some. Me included if it can be done at reasonable cost.

Justin..

You CAN probably do a 2 X NiMH driving a LIII @ > 1A, but this is not the circuit, nor do I believe any are out there for sale as yet, hence the no circuit recommendation comment. You'd have to design from scratch unless there's a post for such.

The circuit I was referring to that I have is voltage regulated as there seems to be no 3V to 6V+ CC boost coverters out there, as well as size re having to add a current sense op-amp. If you're modding a Mag, then you'd have the space so it is also an option, but it's not what I have. I've found that, as per Dat2zip/MadMax, as long as the voltage is set for the Vf of the LED at the given current you require, then this topology works fine. There's very little variation in current as things heat up in the LED. Thermal run-away is not an issue with a Hotlips (well coupled to Mag)/ AS LED to Hotlips or similar good heatsinking solution eg McModule/AS LED to Mc Module for PM6.

Chris

 

[Justintoxicated]

Ok, I think I understand now...
But would your circuit dim as the batteries are depleated since it is voltage regulated? or is that just a charactoristic of the Mad MAx boards??

How would I go about mounting your circuit in the Mag 3C? Willit fit in the backside of the hotlips HS?

 

[RussH]

Justintoxicated, you're right, I meant to say 'j' voltage bin rather than T (brightness bin).

Electrolumens new boost circuit (see his forum) sounds like just what you want. He designed it to boost 2 cells in his flashlights to about 800ma or 3 cells to 1000-1200ma. It is $9 & it wasn't avaliable yet when I checked yesterday, but I'm sure you would at least like to read about it. I plan to buy a couple as soon as they are up on his site. -RussH

 

[Justintoxicated]

I read about it a few weeks ago, but with no ETA or confirmation I'm not sure I want to wait forever....

 

[Burnt_Retinas]

Justin,

The circuit I have = full current until the Batteries are discharged (3 X NiMH or 1 X Li-Ion). MadMax just runs out of huff as the battery voltage drops ie it can't hack the pace, not even at less than 1A. ***edit*** the fact MM is voltage regulated is NOT the reason it drops.

The circuit is 14mm diameter. Very small. Yes it will fit into the recess of a Hotlips C, or a McModule for that matter.

RussH,

Yes I read this about EL boost too. I hope you will publish results if you get then and test them. Separate thread of course. The questions I think of when reading the limited information quoted are:

2 X D = 500mA? Yeah, but down to what battery voltage will it hold the 500mA. Additionally, 500mA/2D is **** weak poor for such a size host required for 2 D's, well under a 3W rated spec.

A 5W 2D? At what current and using what cells for the current? What's the current vs voltage as the batteries discharge?

A 3 W @ 1.2A+ from 3 X NiMH or Alkalines? Yeah, A DD will do that too but without the cost of having the converter. So how long will it hold that current as the battery voltage drops? Would it really be any better than DD?

Chris

 

[RussH]

Hey Burnt, I copied your questions to the file I'm building on this. I will definitely be testing these whenever I can get them. I agree with you about the DD of a 3W @ 1200ma. I built a Mag 3C and a Mag 3D, SV0K (SWAK?), hotlips. The 3C drew 1200ma, the 3D drew 1000ma. I know the internal resistance of a D cell is higher but I didn't think it was that much. The other main difference is the switches, I used the same wire for both. -RussH

 

[Burnt_Retinas]

RussH,

I hope Justin doesn't mind a mini hijack here, but re 3 X NiMH's/LIII. Works great huh /ubbthreads/images/graemlins/smile.gif Tried it myself and yes it works fine. A single Li-Ion works as well as 3 X NiMH so you can DD from them too, including the new 123 sized Li-Ion. Now that'll make a powerful yet small flashlight /ubbthreads/images/graemlins/grin.gif

I myself would still boost an LIII if driving from 3 X NiMH or 1 X Li-Ion so the LED stay's at expected current as the battery discharges. The brightness is noticeable for me as the battery drops in voltage. Additionally, NiMH and Li-Ions will be no where near fully discharged when the light output from a DD LIII gets so weak you are compelled to charge the batteries, so runtime is also lost.

***edit*** Worth noting when using Li-Ions DD'ing an LIII. You have inherent under voltage battery protection. The LED is simply too dim to even consider using well before the battery reached it's limit of around 2.5V. A free bonus when using Li-Ions.

As stated early in this post, my circuit was intended to drive an LV from 1 X Li-Ion, for this of course you'll need a boost. Note 1 X Li-Ion = 3 X NiMH as far as voltage goes. For an LIII, DD is a very real option.....but it's not me.

Justin,

More to ponder over /ubbthreads/images/graemlins/grin.gif

The hardest thing about building a custom flashlight is deciding what you really want. The solution can often be found here at CPF. Technical/technology limitations of course apply.

Have you decided which way to go yet? I may be able to help.

Chris

 

[Justintoxicated]

Sorry, I was away at the mojave desert at Dumont Sand dunes...
I brought my DD lux III with some fresh batts in it and ventured into one of the mines before reading that your not supposed to /ubbthreads/images/graemlins/icon3.gif

I mean I know it was dangerous but this guy that lived out there was showing us around...Very cool place to bust out the Lux III DD... I was snapping shots with my camera and I think I took a picture of a ghost !?!? I later read that there had been a series of murders in the mines and it looked as though someone may have removed the bars on some of the ones that went straight down for some reason (why would people do this??) So it kinda freaked me out when I got home....

I have decided that I want your circuit /ubbthreads/images/graemlins/smile.gif and that it will go into a 3C mag. I have not decided exactly which LuxIII or Lux V I want to use with it. At first I'll probably just run Alkalines untill I can afford NIMH. I ran into a few unexpected expenses right now.


I may try to figure out a way to remove the Hotlips from my existing 3C mag but I have no clue how to do it! if not this will go into a pewter colored 3C mag with a UCL lense with a new hotlips HS /ubbthreads/images/graemlins/smile.gif

So then how do I get the circuit?

 

[Burnt_Retinas]

Justin,

Let me ask a few questions re paypal. I've not received any payments from this service but it's an option perhaps. No sense making this too difficult so I'm sure we can work something out.

I'll PM you with any further issues, including Vf of the LED you intend (needs to be known to set the current as this is a voltage reg remember). Let me know if yo do intend to go a new Hotlips C however. It'd be best for both if I mount it to the Hotlips as it'll perhaps save a thousand words due to mild thermal considerations needing to be considered. Hotbeam is local to me so I could pick one up easy. Perhaps with a bit of arm twisting and compensation for any paypal costs/hassles he may do this also.

Note, I'll also need to know Current, LIII vs LV etc. Cost? - let me work out what covers the parts. I'm guessing around $20 to cover parts/board/building. There'll be no more at that cost though! PM me thoughts and what you want.

If you go the C with LV, you'll have similar to a rechargeable regulated Space Needle! Get a good bin LED if you do this mod. You'll like it. Go the NiMH also. They'll last for a long time as you upgrade the flashlight as LED advancements come along.

Chris

 

[Justintoxicated]

I sent you a PM, I ordered two 3C special eddition Mags today.

I have a Hotlips, but if you think it would be easier if you bought it please do, if you come across a UCL lense from hotlips I'll cover that too.

Only thing I need now is a good bin luxIII or Lux V