# Draco: BRAVO



## lightrod (Jan 6, 2007)

The ultra-small (0.5” x 1.85”) Draco with XRE from modamag is impressive - incredible performance from such a small and lightweight package. This thread has lots of info/discussion:
https://www.candlepowerforums.com/threads/137487
The light is Flupic (PWM) controlled with 3 levels: burst, low, and a user selected level (10 levels to choose from).
Not a throw monster by any means but a LOT of output available - up to 110 lumens (yes that’s 3 digits!!) distributed into a very useful wide beam with a soft spot and bright spill, gradual transitions, no artifacts, rings etc. Here’s the Draco beam profile compared to some other lights. Similar total output but much wider flood than the other XRE lights (A19 and P1D-CE) – beam somewhat similar to the SF L4’s very floody “wall of light”. Note the very wide "secondary spill":






Level 4 provides more than enough of light (20-25 lumens) for about any task, and runs an amazing 75 minutes on a tiny rechargeable (unprotected) 10280 cell:






Here’s the detail on what I got for all levels (runtimes estimated using level 4 runtime as a baseline then scaling all other levels based on lumens – probably pretty close since this light is PWM):





Primary intent is for a keychain but I will carry loose. Look and feel is very high quality. 

Not surprisingly, it gets very hot on burst within a couple minutes and not a good idea to run much longer than that on burst. 

Overall a fascinating light that may be showing a glimpse of the future – outrageous performance for size. Congratulations to modamag!

[EDIT 1/27: since the original post I have found that the light does NOT get excessively hot on burst if held in the hand. My original post was based on observation with the light sitting on a wooden block – not representative of actual use. Also - below is a schematic of the operation of the Flupic v2. Not sure if it helps, but I’ve tried to expand on the supplied user guide schematic in an attempt to make it a little more descriptive/understandable. In any case, for what it’s worth….]


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## 9volt (Jan 6, 2007)

Nice info, mine should be shipped any day now. Can you repost or PM your runtime chart in plain text so I can copy/paste it?


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## lightrod (Jan 7, 2007)

dammitjim said:


> ...Can you repost or PM your runtime chart in plain text...


 
No problem - PM sent....


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## coyote (Jan 7, 2007)

great info. thnx!


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## ShortArc (Jan 7, 2007)

Very useful information, thank you!
Does your Draco exhibit a momentary “flicker” approx 2 sec after you turn it on?


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## rscanady (Jan 7, 2007)

The flicker is a function of the Flupic.


Ryan


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## BrightGal (Jan 7, 2007)

lightrod said:


> ... outrageous performance for size.



I got to play with a Draco recently and I think you have nailed its essence in your review.


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## Secur1 (Jan 24, 2007)

Uhm erm i've been looking over and over at the Flupic manual but i just don't get it...
To me the light workis like

Turn 1 Burst
Turn 2 Lower, almost half the light from burst
Turn 3 Low
After that there is a mode where i turn on the light, wait a few seconds and then it lights up in burst mode...
So how do i access the 10 different user levels ?


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## 9volt (Jan 24, 2007)

1st = High 
2nd = User set level
3rd = Low
4th = No light 
5th = Quick Flash (Program the light here)

At the 5th settting (the one after No light) it will Quick Flash, and then slowly step through the 10 levels of light, going from 1-10 and then 10-1. Whatever level it is at when you turn the light off during this sequence is the level that the 2nd turn (User set level) will be set to.


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## lightrod (Jan 24, 2007)

Just updated the runtime plot with a couple other levels included beyond the original level 4. Based on the new info I think the table is about right in its estimates for runtime for each level.


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## lightrod (Jan 27, 2007)

Added burst level to the runtime chart; corrected a comment on the heat from the light on burst; added a schematic of the Flupic v2.


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## 9volt (Jan 27, 2007)

lightrodadded a schematic of the Flupic v2.[/QUOTE said:


> On my light the 4th twist gives no light and the 5th gives a flash and then the 1-10 levels. Does yours give level 1 light on the 4th twist?


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## lightrod (Jan 27, 2007)

dammitjim said:


> On my light the 4th twist gives no light and the 5th gives a flash and then the 1-10 levels. Does yours give level 1 light on the 4th twist?


 
Thanks dammitjim - you are absolutely right - a copy/paste error on my part. Fixed.


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## jch79 (Jan 29, 2007)

Lightrod - your schematic, although complicated at first glance, really breaks down the operation of the FluPIC, and helps dummies like me know what's going on. Thanks! :thumbsup:
john


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## flashgreenie (Jan 30, 2007)

thanks lightrod, really hepful post. I got mine yesterday and immediately blinded myself by turning it on while looking at the bezel Amazed at how bright this little thing is.


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## loveit (Jan 30, 2007)

I'm waiting for this next round to finish up to get my Draco. You all have me very excited about getting this light. I ordered the titanium version. All of these great reviews have really pushed me to the Draco. I hope I'm not disappointed. I am new to these flashlights and just received my first McGizmo PD-S. There is nothing like starting at the top!


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## frisco (Feb 2, 2007)

moved


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## Lurveleven (Feb 5, 2007)

lightrod, can you do runtime graphs for level 5 and 6 as well?

Sigbjoern


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## lightrod (Feb 6, 2007)

Lurveleven said:


> lightrod, can you do runtime graphs for level 5 and 6 as well?
> 
> Sigbjoern


 
I can get to this before long I think - expect the runtime to be very close to the table values. Unlike current regulated lights, with PWM the runtime will be very close to inversely proportional with the output (e.g. 1/2 the output will give 2x the runtime) since efficiency is not gained at the lower levels. With current regulation 1/2 the output will provide more like 3x the runtime since the LED operates more efficiently (more lumens per watt) at low levels.


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## AndyTiedye (Feb 6, 2007)

lightrod said:


> Unlike current regulated lights, with PWM the runtime will be very close to inversely proportional with the output (e.g. 1/2 the output will give 2x the runtime) since efficiency is not gained at the lower levels. With current regulation 1/2 the output will provide more like 3x the runtime since the LED operates more efficiently (more lumens per watt) at low levels.



Why is this? And given that it is so, would filtering the PWM back into DC
improve efficiency?


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## lightrod (Feb 7, 2007)

AndyTiedye said:


> Why is this? And given that it is so, would filtering the PWM back into DC
> improve efficiency?


 
I'm far from expert on this but here's my simple take on this - and I'd welcome a more knowledgeable input on this!

Suppose on a given light/battery the LED is being driven continuously at 450 mA, provides 50 lumens of output, and runs for 20 minutes. With PWM, the way the output is reduced to say 1/2, or 25 lumens in our example, is NOT to reduce the current, but to rapidly alternate the light on and off for short periods - 1/2 of the time on and 1/2 of the time off in basically a square wave pattern (e.g. 5 ms on, 5 ms off, repeat - too fast for the mind, at least MY mind! - to distinguish from steady). During each "on" period the current is the same - 450 mA. The LED efficiency does not improve for the on periods as compared to the "always on" / full output case. So the draw on the battery is happening basically the same as the "always on" case, except half as fast since the light is on only 1/2 the time. So the battery lasts almost exactly twice as long, or 40 minutes. It's basically the same argument for cutting output by 1/4 (80 minutes runtime), 1/8th (160 minutes runtime), etc.

This ignores any tendency of the battery to behave differently with rapid alternating pulses vs a steady draw, but I think this is a minor factor at the rate this is all happening. 

Now, with current regulation, the runtime is the same for the "full on" case, but the way the light attains 1/2 the output is to reduce the drive current. Since LED efficiency improves at lower currents, the light in question may be able to provide 1/2 the output or 25 lumens at only 150 mA, or 1/3 the current of the full output case. So then the draw on the battery is not 1/2 the rate but about 1/3 the rate, so it will last about 3x longer.

This effect continues to "compound" as output is dropped further - e.g. cut in half again to 1/4 output (~12 lumens)and now compared to full output it may be 4x the runtime for the PWM light but 9x the runtime for the current regulated. At 6 lumens it's 8x and 27x, and at 3 lumens it's 16x and 81x. By then note the current regulated light is running about 5x longer then the PWM! All these are approximations but I think it gets the idea across. 

I do not know about filtering methods for PWM, but that would seem to boil down to a type of current regulation if it could be accomplished.


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## LightBright (Feb 7, 2007)

Yes, you can drive LEDs with variable DC circuits, I have such a design. 

Something else I, Newbie and probably others have noticed about PWMing an LED - the TINT of the LED changes somewhat dramatically as the current changes. So a PWMed LED driven very hard, lets say at an average of 3 watts, will have a different tint (ugly) than when driven at 3 watts with DC current.


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## crewcabrob (Apr 2, 2007)

Hi,

I have been looking at the run times here for the various modes, and i find that my run times are similar. 

I'm thinking about buying the extender tube and the larger 10440 batteries. I'm guesing that since these are about 1/3 larger than the 10280 cells, I should expect about 1/3 more run time. Does that sound correct? Any one have experience with the larger cell in the Draco?

Awesome light, I just can't put mine down.

Thanks Lightrod for all the great info on this little gem.

Rob


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## DM51 (Apr 2, 2007)

The 10440 cell has a rated capacity of 320mAH, the 10280 has 180mAH. That is an additional 77% capacity - 3/4 extra, not 1/3.


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## AndyTiedye (Apr 2, 2007)

I think the "LOW" setting is more like level 3 than level 1.
I set the user-settable level to 1 and it is clearly lower than "LOW".


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## gregflier (Apr 2, 2007)

My two chrome Draco’s arrived on Thursday and I am very happy with them. 

On one the “low” setting is level 1 (lowest), on the other one “low” is about level 3. I assume the flupic’s have different programming somehow. I’m not sure which variant I like better.

I am continually amazed by how much light these little gem’s put out and how useful they are. I was actually looking foreword to going to work at 5:30 this morning so I could use my new lights and I am NOT a morning person.

Greg


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## crewcabrob (Apr 3, 2007)

DM51 said:


> The 10440 cell has a rated capacity of 320mAH, the 10280 has 180mAH. That is an additional 77% capacity - 3/4 extra, not 1/3.




Wow, I guess I should have looked closer at the cells. Any one tested the larger cell for run times.

That seals the deal for me. I'm going to order the extender tube and 2 cells. 

Thanks guys!

Rob


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## riasa (Apr 3, 2007)

Usually a logarithmic scale is used to compare levels of significant difference. Not good to see the Draco at the bottom of the chart.


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## crewcabrob (Apr 3, 2007)

riasa said:


> Usually a logarithmic scale is used to compare levels of significant difference. Not good to see the Draco at the bottom of the chart.



Hi,
Can you elaborate on this? I lost something reading through the thread, and I'm not sure what you mean by this?

Thanks,

Rob


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## DM51 (Apr 3, 2007)

riasa said:


> Usually a logarithmic scale is used to compare levels of significant difference. Not good to see the Draco at the bottom of the chart.


What chart? WTF are you talking about?


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## riasa (Apr 4, 2007)

I'm sorry. The graph at the start of the post. Look at the y axis...10, 100, 1000. Most of the graphs I've seen are linear...1000, 2000, 3000, 4000, 5000. I guess the reason a log scale was used in this case was because two of the lights in the comparison were of several orders of maginitude brighter than the other two.


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## Somy Nex (Apr 4, 2007)

riasa said:


> I'm sorry. The graph at the start of the post. Look at the y axis...10, 100, 1000. Most of the graphs I've seen are linear...1000, 2000, 3000, 4000, 5000. I guess the reason a log scale was used in this case was because two of the lights in the comparison were of several orders of maginitude brighter than the other two.



actually a log scale makes more sense and tells you more, when used to measure human senses.

just like sound, touch, taste, and smell, our sight also registers inputs logarithmically. so actually those linear scales are misleading, while the logarithmic scales put it in a way our 'linearly trained' brains can easily understand.

anyway, i'm going to assume the draco measured is a xre draco, as the lights it is being put up against are eithe xre or LuxV lights. the reflector (size & quality) is among the most important things determining output, and given the draco is a fraction of a fraction of the size of the other lights, i think it compares extremely well. =)


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## lightrod (Apr 8, 2007)

Data point for what it's worth: just washed and dried my Draco. It didn't need it. But I suppose it came out cleaner..... and unharmed.... and working. No problem. Whew!


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## FsTop (May 2, 2008)

Extending Lightrod's outstanding work slightly, I multiplied out the runtimes for 10440 (the "AAA" extension tube) by assuming a 75% increase in battery capacity for the 10440 vs. 10280.







IMHO, with the 10440/AAA extension, the Draco competes well on runtime and brightness with the best of the 10440 single-cell lights, and has the best beam I've seen on a keychain. It is also the most compact high-output AAA light that I've seen. 

The Draco is a beautiful piece of design in all respects.
:twothumbs


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## xcel730 (May 8, 2008)

Does the AAA extension tube work with NiMh or only 10440 cells?


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## FsTop (May 8, 2008)

The extension tube allows short 10440 - many AW cells are too long. The Draco requires a Li battery.


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