Arc-P AAA CS vs. DS Runtime

this_is_nascar

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I was able to dig up some old data in order to save me some time. In addition, I found my cable so I can offload data from my light meter. Anyway, here's a quick comparision of the DS vs. CS emitter in the Arc-AAA light. For this test, Ray-O-Vac alkalines were used.

CS-DS-1.jpg
 
Nice clean graph. Thanks TIN. This confirms what we suspected, which was a slight increase in runtime in addition to the higher brightness. I suspect that the lower vf, combined with partial current regulation, means less power is drawn from the battery.

peter
 
...partial current regulation...
Peter, what exactly is this "partial current regulation" you're talking about? How's it different from current regulation, or voltage regulation?
:thanks:

TIN - nice to see you back and posting.
 
Thanks for the kind words everyone. Here's another one for you. You old-timers will remember the Arc AAA Limited Edition (LE). Look how technology has really changed over the last several years.

... problem with the pic. Stand by.

Here it is.

CS-DS-2.jpg
 
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I think the original LE had a BS Nichia LED. There is a lot of light between the the CS and DS, especially in the middle where it curves in the opposite direction.

I say partial current regulation because the system limits the current through the inductor, which reacts with the vf of the led and the discharge curve of the cell to produce a form of current regulation to the various LEDs. If it was voltage regulating (which some people think), the runtime and brightness would vary much more from unit to unit.

thanks again TIN!

peter
 
Nice graph, TIN!

I say partial current regulation because the system limits the current through the inductor, which reacts with the vf of the led and the discharge curve of the cell to produce a form of current regulation to the various LEDs. If it was voltage regulating (which some people think), the runtime and brightness would vary much more from unit to unit.
peter

Mostly semantics. The circuit is configured as a voltage regulator, however, due to the switcher chip's parameters (for output current (a function of inductor current) vs input voltage), the current gets limited. With a 3V input, the output current should go up considerably - up to 100mA @ 5V (of course it will depend on the load).
 
Peter, what exactly is this "partial current regulation" you're talking about? How's it different from current regulation, or voltage regulation?
:thanks:

TIN - nice to see you back and posting.

Yes, it is good to see TIN posting again. Hopefully he will stay awhile.

greenLED, I've posted about this before. The question comes up from time to time. Let's take this to another thread (go back to arc main to see it) since this is off topic. Chimo, you appear to have some questions as well and you are welcome to join us.

peter
 
Great graph TIN! It was really cool and informative to see the progression in LED efficiency of the Nichia.

It is really impressive to see a small light such as the Arc AAA now able to put out such a "practical" amount of light with a similarily impressive runtime. It is just so handy and easy to keep a light like this with you all the time.

I remember thinking how practical the original Arc was with the amount of light it put out. Can you imagine how shocked people would be if the DS came out right ater the original?
 
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Welcome back, TIN
I remember back in the day of my original AAA-P and it is quite a difference with the DS. Wonder how the runtime and graph is with a Eneloop AAA? The output would probably drop but have a very flat discharge curve.
 
I still have the ArcAAA Std you sold me TiN. I modded it to a hand picked CS LED. Too bad I re-potted it in 2-ton epoxy or I would make a DS. Oh well the difference from CS to DS isn't as big as BS to CS. Because if you look at your graph, the jump from BS-CS is x2, while the jump from CS-DS is only 1.5x.

Eneloop AAA is something I'd like to get. I wouldn't use it in my ArcAAA since the draw is so low that alkalines work fine, but in my LOD-CE it would benefit a lot and yet not have to worry about self discharge.
 
Peter, now if you could only take this new led and make some type of AA housing for a light with much longer runtime only what would we call it? :whistle: One can always dream
 
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