4+ draws 2A+ in level 1?

Is this correct? With my DMM in series with the 4+ circuit I am seeing over 2 amps being pulled from the battery. In 4 samples (same battery) I got:

#1. 2.19A (first quality)
#2. 2.4A (second)
#3. 1.58 (second)
#4. 1.6A (second)

I read where Peter G. said that the 4x draws 1.5A? I'm confused. /ubbthreads/images/graemlins/thinking.gif

Granted, this is not professional equipment I'm using here ($40 Craftsman DMM) but does this sound correct? For reference I did the same thing with a modded LSH-P with the circuit re-worked at 667mA. That one reads .67/.68 with the same meter.


Peter

Peter,

I have been puzzling over this too. I measured 1.58, 2.57, 1.73, 1.64, and 1.09 Amps -- all firsts, all on a fresh battery. I also measured brightness and runtime (until the light downshifts levels) in a thermally insulated compartment. There is a mild negative correlation between current and runtime, but it's not as strong as I would have suspected. There is no correlation I can see between current and brightness.

I'm confused too. A range in battery current of 2.57 to 1.09 represents a ratio of 2.37 -- much more than I would have expected. Since Arc's calibration is designed to match Level 1 with a given standard brightness, I would think the range in current from light to light would be no more than the step size of two adjacent current levels, which is a ratio of 1.41.

I am now comparing two of these lights with a more full runtime (8 or 9 levels). Maybe that will reveal something.

Paul

I wonder if you can look at the current drain with an oscilloscope instead of a meter. Maybe the load isn't constant.

Paul -- No scope here. But that's a great idea. I wonder how many have both a scope and an Arc4. Peter?

No scope here, not that I would know what to do with it anyway. /ubbthreads/images/graemlins/smile.gif

Paul, are your #'s also in level 1?, I assume they are. Wow, that is quite a range of current. I'm not at all knowledgeable about this sort of thing, but it seems like the calibrated brightness is coming at significant cost as far as the batteries/runtime is concerned?

Peter

LitFuse,

You have done numerous LS mods with BB667/750 and LuxIII. Could you give us a comparision between these and the Arc 4+ at level 1 illumination. I realize that this is an 'apple vs. orange' issue and doesn't have a lot of validity to it, but I am curious none the less.

I suspect the modded LS will be brighter.

I suspect the Arc 4+ will have a larger hotspot and greater throw due to it's reflector vs. Fraen LP optic.

I suspect no matter what you say, I will purchase a 4+.

[ QUOTE ]
EvilLithiumMan said:
I suspect no matter you say, I will purchase a 4+.

[/ QUOTE ]

excellent suspect-tion /ubbthreads/images/graemlins/thumbsup.gif

/ubbthreads/images/graemlins/grin.gif

i too would like to know what EvilLithiumMan wants to know.
i have an arc twak/fraen/667mA and would appreciate it if someone would put some beam shots up of an arc supermodLS against the arc4+, or maybe against the arc4x /ubbthreads/images/graemlins/poke2.gif if its not too much trouble

Hmm, interesting. I got consistent results with my DMM, though I'm sure the internal resistance of DMM causes distortion.



At the level 1, the battery drain was 2.55 V x 1.18 A = 3.009 W. At that time, the battery had been slightly used for other measurements. With a very fresh battery, I saw the current was roughly 1 A.

I did this measurement a week ago, but I did not post it until I saw this thread because I know my result must have some error. I still hope someone who has a good equipment try measuring these current / voltage and correct us /ubbthreads/images/graemlins/smile.gif

[ QUOTE ]
EvilLithiumMan said:
LitFuse,

You have done numerous LS mods with BB667/750 and LuxIII. Could you give us a comparision between these and the Arc 4+ at level 1 illumination. I realize that this is an 'apple vs. orange' issue and doesn't have a lot of validity to it, but I am curious none the less.

I suspect the modded LS will be brighter.

I suspect the Arc 4+ will have a larger hotspot and greater throw due to it's reflector vs. Fraen LP optic.

I suspect no matter you say, I will purchase a 4+.

[/ QUOTE ]

I figured it was only a matter of time 'till I was going to have to answer this one... A couple of points first though:

1. This really is an apples vs. oranges type of comparison as ELM said, take it for what it's worth.

2. I *love* my 4+, and it's the light I carry everyday. If I had to have only one light, this would be it without question.

Having said that, the 667mA modded LS is *much* more impressive at a distance of 100'-150' (this is how far it is across the street to the trees in my neighbors yard). It just "lights up" the whole canopy of trees at once. The 4+ hotspot lights up perhaps 1/3 of the area that the Fraen does. The 4+'s copious sidespill that is so useful at closer range just doesn't go the distance of the Fraen LP. The brightness seems about the same to me, the 4+ *may* have a very slight edge. At the limits of both lights range, the 4+ has just a little longer throw, but the Fraen is right there behind it, and with a much larger hotspot. /ubbthreads/images/graemlins/smile.gif

As I said before I love my Arc4+ , but I also love my modded Arc LS 667 w/ Fraen. For throwing a wall of light at something in medium to longer distances, nothing else even comes close! And it'll do if for an hour straight too! /ubbthreads/images/graemlins/smile.gif

Here's a couple of pics.

4+ (left) vs. Arc LS Q3J (not Lux III) @ 667mA (right)



And just for fun (and because I just finished it) vs. Lux III cyan @ 667 mA /ubbthreads/images/graemlins/icon15.gif





Peter

[ QUOTE ]
LitFuse said:
Is this correct? With my DMM in series with the 4+ circuit I am seeing over 2 amps being pulled from the battery. In 4 samples (same battery) I got:

#1. 2.19A (first quality)
#2. 2.4A (second)
#3. 1.58 (second)
#4. 1.6A (second)


[/ QUOTE ]
While I can't tell you why you're seeing what you're seeing, I can tell you that it is *highly* unlikely (I don't like using "impossible" but I'd like to!) that anything will be able to consistently pull over 1A out of a single 123 cell.

kj's numbers are closer to what we see in production. 1-1.1 amp is average. Seconds will draw more than that usually.

If your test equipment introduces any resistance in the circuit, the micro will compensate by drawing more current in order to maintain the brightness.

Duracell rates their cells for about 50 minutes at 1amp. You will most likely reach thermal limit before that of course.

Peter

I guess I should have written that down?...../ubbthreads/images/graemlins/thinking.gif


Peter

Maybe I'm missing something, but isn't the Arc4+ power regulated, rather than current regulated? So wouldn't the amps be expected to vary?

LitFuse, thanks for the pictures

You're welcome Faran.

So has anyone else put a meter on their 4+ and measured the current in level 1?

I still don't understand why there is such a variation (1.09A to 2.57A!) from unit to unit. Is it because of the incremental, calibrated brightness that is maintained regardless of the individual characteristics of any given LED?

Anyone? /ubbthreads/images/graemlins/help.gif

Peter

I put my Arc4+ on a fresh cheapie yuntong's and it draws 0.82A. I then proceeded to use an HP power supply and put it on 3V and it drew 0.8A. Moved voltage up to 5.5V and it drew about 438mA. At 6V it drew 405mA. My conclusion is that I have a pretty efficient LED. Another conclusion is that the regulator efficiency is remarkably constant as it pulls ~2.4W from the power supply irrespective of the input voltage.

I'm surpised at the >2A current draw on your samples. A single 123 does not have the huevos to sustain that draw for more than a few minutes.

I only have one 4+ to play with right now so my data is just a single sample point among many. Peter (Litfuse), you have way too many Arc4+'s /ubbthreads/images/graemlins/grin.gif

I suspect the variation has to do with the fact that the light is calibrated for output level--damned the batteries. The units drawing in excess of 2A should have been sold as seconds--it's too much current. Be aware that ammeters do introduce some resistance and what you're reading will most likely be showing higher draw than if the meter wasn't there. A good ammeter will minimize the Heisenberg uncertaintly principle so make sure you use a good meter when measuring current draw.


CM