ARC AAA - just voltage step up, no regulation !

I just bought my ARC AAA at US$21.5 while most shops here sell at $25. However when I measure the V/I curve, it seems that the circuit inside is only voltage step up but not voltage regulation. My measurements are :

V=1.50V I=240mA
V=1.41V I=240mA
V=1.33V I=230mA
V=1.27V I=180mA
V=1.21V I=140mA
V=1.15V I=95mA
V=1.07V I=77mA
V=1.00V I=73mA
V=0.91V I=60mA
V=0.82V I=55mA

This V/I curve showed that the input power goes down as the voltage. The light output should also go down as the voltage.

In a true voltage regulating step up circuit, the output voltage to the LED (which I cannot measure as it is sealed) should keep constant. Input current should increase when input voltage decrease, this is to provide same power to the output. Usually input power goes up slightly as voltage goes down, because efficiency is worse at lower voltage.

Without a regulating effect, the LED light output cannot keep constant while the battery voltage drops.

I don't have a meter to measure the luminance. Can anyone tell me whether you observe the luminance drop as the battery time.

I want a Flashlight with TRUE constant light (with regulator circuit). Does the Inova X1 produce constant output during most of the battery life ?

Any other measurement on Arc AAA or X1 is most appreciated.

Re: ARC AAA - just voltage step up, no regulation

Peter from ARC flashlight calls it "semi-regulation" and speaks about why he chose this for ARC flashlights. I run my ARC-AAA on NiMh's and appreciate knowing how much energy is in the battery, it is also the brightest EDC keychain light I own. You are right though, it is not a fully regulated light, neither is the ARC-LS, though it is reported to be more linear.

cheers, Nick

PS check out the ARC flashlight forum for more info on the design of these lights, alot of though has gone into them and it makes for good reading about the challenges of good design.

Re: ARC AAA - just voltage step up, no regulation

Yes, you can see the brightness of an ARC drop off as the battery gets weak. Same/same with my SureFire KL1. For constant brightness try an Opalec drop in module for a minigag or the SF L4. Different lights, I know...As NickA said, there is a lot of good info on the ARC forum about why they are the way they are.

Re: ARC AAA - just voltage step up, no regulation

True regulation can probably only be found in the Opalec NewBeam. This is a 3 LED drop-in mod for MinMag 2AA. The regulation is so flat they had to include a red warning LED to let you know that the cells were nearing their end-of-life.

The next flatest (if there is such a word), would probably be the EverLED. Again, this is a drop-in mod. It is meant for PR-based bulbs and will run from between 1.5V to 9V. According to the website, the output doesn't look all that flat, but I understand that this will only happen if you start from 3V. Another CPF member once ran the EverLED through the entire range starting from 9V down to 1.5V. He found that there was increasing current draw with decreasing voltage, and the power output appeared relatively flat. But below 3V, it seemed that the EverLED could not squeeze out enough juice to maintain regulation.

Of course you need to ask yourself, "To what ends do I want regulation"? Regulation means that the circuit is capable of delivering more power but is kept in check and throttled to maintain an even output. Most people just want blindingly bright. So if the circuit can deliver that extra power, and the heatsinking is adequate, they think "why not" and blast away.

In the case of the EverLED, they have to keep the power in check because they don't know what sort of flashlight you are going to use and therefore have no idea how good the heatsink will be. I'm not sure why Opalec did it. Probably responding to market expectations, but just as likely because 5mm LEDs can't be effectively heatsinked. I think they could have popped in 2 or 3 more LEDs.

Personally, I think the only usefulness of regulation is in a personal tasklight, for example, in a book light. I don't want to start out with blindingly bright and drop off to dim, I want the same level of brightness as I turn the pages. But for flashlights, give me bright-as-it-can-be. Probably the only exception would be in an emergency light where I am able to count on a minimum level of brightness from start to end. But I can work around that.

Re: ARC AAA - just voltage step up, no regulation

The other nice thing about the semi-regulation is that it prevents the slow oscillation you get from a truly regulated light. You know, the light drops out because of low voltage, the batteries go back up a bit without the drain, the light comes back on, the batteries drop down again, the light goes off, the batteries come back up, etc.

Re: ARC AAA - just voltage step up, no regulation

Eh? My KL1 flickers when the battery is near gone. Now I'm confused.

Re: ARC AAA - just voltage step up, no regulation

almost all my regulated lights (BadBoys, KL1, KL3, KL4, ArcMania Pill, Downboys, Arc LS) do flicker more or less when they fall out of regulation. I take this as a warning sign for the last minustes of useable brightness to come.

Tech a Billy: the KL1 should be current regulated.

bernhard

Re: ARC AAA - just voltage step up, no regulation

I wouldn't change a darn thing about the ARC AAA. I love the fact that the "moon mode" is there, rather than "ruler flat" regulation. Moon is still useful, and... I dunno. I just think it's better for the flashlight.

(Okay: Wish list: If there was a trim pot so I could decide how fast/slow moon mode came on.)

Re: ARC AAA - just voltage step up, no regulation

Why call it "semi-regulated" if it's not regulated?

Brightnorm

Re: ARC AAA - just voltage step up, no regulation

Regulate: to control or adjust to a certain specification.

The specification could be a specific value (metric) or a basic logic. In the case of a metric, true regulation would only occur when the output met a certain value. Obviously, that metric requires a tolerance (+-) instead of an absolute. Otherwise, we could say that there is not such thing as a true electronic regulator.

The idea of an electronic regulator is to overide the discharge curve of the battery in order to provide a more consistant output.

How well it does that is the extent at which it a "perfect regulator".

To simplify things, I use the term "semi-regulation". I hope this explains well why the output is a mixture of the battery discharge curve and perfect regulation.

And if you read the long piece I wrote in the Arc forum, you may also understand why I feel such a regulation scheme optomizes the output for a given set of features.

If anyone feels the term, "semi-regulation" is less than accurate, you are quite welcome to prove your point.

Btw, this thread is a double thread. And indentical thread was posted in the Arc forum.

Peter

Re: ARC AAA - just voltage step up, no regulation

[ QUOTE ]
Gransee said:
...If anyone feels the term, "semi-regulation" is less than accurate, you are quite welcome to prove your point..

[/ QUOTE ]

Peter,

My question was informational, not contrarian.

Brightnorm

Re: ARC AAA - just voltage step up, no regulation

Brightnorm,

I wasn't trying to beat you up or anything... /ubbthreads/images/graemlins/smile.gif



I use the term, "semi-regulation" to describe a type of operation that combines both true regulation and the discharge curve of the battery.

Although this type of circuit has limited utility were power supplies are typically used, they do have a usefulness when applied to flashlights.

The most telling indicator of semi-regulation is the steep drop off when the input voltage reaches a critical point.

The advantages of semi-regulation are:

- small circuit size
- some of the advantages of regulation like a more consistant light output over the life of the battery
- maximized brightness over the typical task length (for a given configuration)

Peter

Re: ARC AAA - just voltage step up, no regulation

Gransee,

Would you consider this full regulation circuit in the new ARC products.

http://www.candlepowerforums.com/ubbthreads/showflat.php?Cat=&Board=UBB14&Number=428278&page=0&view=collapsed&sb=5&o=&fpart=1

I would love to buy ARC flashlight with following spec :
1. 1W Lexeon
2. Use 1xAA
3. Full regulation from 0.8V up
4. Use similar cirucit as my solitaire mod OR better.
5. As compact as possible

I will test a circuit later for a 1W Lexeon and give you my patent and design. I can make good electronics but require the quality housing built by ARC.

Re: ARC AAA - just voltage step up, no regulation

James, thank you for your suggestion.

I have already selected, tested and manufactured full regulated versions of the Arc-AAA w/5mm (See "XR").

An Arc-AAA or AA with a Luxeon is being considered, but no products are on the schedule yet.

Most of my current design effort is going into new LS models and improving reliability of all our flashlights.

Peter

See \"XR\"

Gransee: 'I have already selected, tested and manufactured full regulated versions of the Arc-AAA w/5mm (See "XR").'

Peter, I searched around for the "XR", couldn't find a link. Can you point us there?

Thanks

Re: See \"XR\"

Do a search with these parameters:

Category: Arc Flashlight
Words to search for: arc aaa xr
Search options: And
Date range: All posts

and others with default values. This pulled up a few threads for me.

- Russ

Re: See

Sounds line there may be enough interest to twist Peter's are to re-make a couple hundred of these XR's.

Re: See

very much interested and would buy if an AA or AAA arc was made that was fully regulated.

Re: See

I would be interested too if I could get one /ubbthreads/images/graemlins/smile.gif

Re: See

Why was the full regulated discontinued and what was the runtime compared with the current model? I'm assuming it also has a sun/moon mode like the LS. If it doesn't compromise the sun mode runtime much, I would probably prefer this light over the semi-regulated one.