Regulated LED Flashlights

After over a Week living with my Arc LE, I'm a convert. I feel GUILTY putting rechargables in it! (Only Alkalines for you, baby)

Anyhow. Other than the Arc AAA and I presume the ARC LS, any other LED flashlights using REGULATION (Not just Step Up) and never dim?

I'm interested!

--Phil

Sorry, but what is your problem or your question?

I think he's asking: Are there any other lights, other than the ARC line of lights, that use some sort of regulation to either prolong burn time or brightness?

My answer would be, not at this time - to my knoledge. I too have been "turned on" to regulation, but have not found any other company to offer such technology in their lights.

Surefire's digital line (when its ready) should be something to look out for. I think the PAL lights are regulated too. Then, of course, there are the eternalights, pocket brights and photon 3s. Except for the Surefires, I think the others are step-down regulated, rather than step-up. Won't be surprised to find more in the coming months.

For non-flashlight regulated LEDs, there is the 10-LED Versalux Utility Light Module. Its dimmable and takes an input voltage of anywhere from 2.2V to 13.8V - now *there's* an example of regulation

I know there are regulated incandescent AC *bulbs* for the household too, but I digress....

The eternalights are regulated? I didn't know that.

They are regulated in a sort of way. I wish someone would come out with a truly regulated light, meaning the light output is the same in the first 15 seconds of battery life as the last 15. I think (hope) the Surefires will do this. Most of the other lights, (Pal, Eternalight & Arc) all dim as the batteries die. They don't dim as fast as the battery voltage drops, but they still do drop in intensity a bit over time.

I started a thread on that very topic a while back, Brock. The loss of run-time would be dramatic if the light was totally regulated (and bright). The way Arc (and some others) handle this task really is a great compromise. I feel the same way you do, though. It was the reason I asked the question in the first place. I'm sure that better electronics will get us closer and closer to that goal...

regulation thread

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by Brock:
They are regulated in a sort of way. I wish someone would come out with a truly regulated light, meaning the light output is the same in the first 15 seconds of battery life as the last 15. I think (hope) the Surefires will do this. Most of the other lights, (Pal, Eternalight & Arc) all dim as the batteries die. They don't dim as fast as the battery voltage drops, but they still do drop in intensity a bit over time.<HR></BLOCKQUOTE>

Regarding voltage regulation, I have found that even with a dc/dc switching regulator, the light will dim as the batteries wane. The reason being that when the batteries go low, they physically cannot provide the current the regulator is demanding. It's a matter of physics. If you have 2 AA batteries, for example, when they are fresh, they can easily provide 350mA, or even 500mA, but when they have been used up somewhat, down to 1.7 from 3.0 volts, they just cannot provide the necessary current. It doesn't matter how good the regulator is, the batteries cannot do it.

It is doubtful there is any flashlight that shines at full brightness for the entire lifespan of the batteries, unless there is some sort of cutoff circuitry, to cut off the current.

Read through the posts and look at the voltage/current charts, and you'll see what I mean.

This is why I've put together a bunch of flashlights that do not use voltage regulation circuitry at all. I've been using 3 'D' cells, with only 1 ohm resistance. I get a real good bright light for at least 24 hours, and even after 36 hours, the light is still useably bright. I just pop out the old batteries after 24 - 36 hours. That's way more time than voltage regulation would give me.

The only place I can see any use for voltage regulation circuits is when you want to have a very small size flashlight, like using 1 or 2 batteries. Otherwise, just use a little resistor.

I am a huge proponent of voltage regulation circuitry. I made several boards of my own design, and put together a number of regulated flashlights. Two 'C' batteries with a MAX757 regulator gives me around 6 - 8 hours of bright light. Three 'C' cells will give me 24 hours or so of good bright light. That's three times as long or more, and I didn't have to spend the $20 or so to make the regulator, and saved all that time making the regulator.

Wayne www.elektrolumens.com

I do understand that batteries only have so much power in them and that they can't supply enough power when they are dying. I also understand that a truly regulated light would run much less time then a not so regulated light. But that doesn't mean I don't want it Take the case of the E2. I would be willing to have a 45 minute runtime with that "fresh battery" brightness. Rather then the 70 with slowly dimming light. It is funny really, a lithium battery's output curve is SOOOOOO much better then alkaline, and yet I still find myself wanting something with a flatter output. I think that is one of the reasons I got in to LED's was that they don't turn yellow as the batteries die.

I would like to see companies use 4 AA alkaline cell light that have the output of a current P60, E2 or even a P61, with the same (or longer) runtime on batteries about 1/3 the cost and not much larger and a lot more commonly available. If you look at the UKE 4AA and the UKE 2L, using the same lamp the 4 AA starts to dim much sooner the 2L even though it runs about twice as long. I guess that is my biggest reason for good regulation.

Realistically I think Arc, Pal and Eternalight really have got it about as good as a trade off as we can do. But again I would like to see this implemented in a 4 AA or 6 AA light.

Thanks for the response.

There is a company called "CAIG" that challenges you to take an old flashlight (An Everready Captain, fr'instance) and spray it with De Oxit.

Then, notice how much brighter it is.

Currently, I'm still on my first AAA battery in my LE.

It's a cheap, chinese Heavy Duty AAA I got free in a keychain light.

I smashed the light intentionally to salvage the battery.

The battery will not light up my MP3 LCD display or my pager. It BARELY lights up my LED battery tester (Red-No good)

But it shines like a new duracell!

I'm addicted!

That was my real question... It would be nice to get a light that is as perfect at the first 15 seconds as the last.

This is a fine compromise... For now!

Phil

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by Brock:
I would be willing to have a 45 minute runtime with that "fresh battery" brightness. Rather then the 70 with slowly dimming light.<HR></BLOCKQUOTE>

I'd want that same thing. BUT, and that's a big BUT - I'm afraid if you want the first 15 second brightness for the life of the batteries, I'd (totally subjectively) guess you be looking at more like 15 minutes of light from an E2, not 45. At least that seemed to be the conclusion in the thread that I started. If somebody could build that 45 minute light, I'd but it. BUT, (yup, another big one) I'd need that light to have a fuel gage, since we'd be removing the dimming gage found on all other lights.

i do believe, because of the statements about their rechargeable 123s that can only be used with their new lights, that the new surefires are step-down regulators...meaning that the light output will stay rock-solid until the voltage of the batteries is below that of the voltage output...

i looked into a better form of step-up regulation a little, but the only good way i could find was a regulated charge-pump type...and for these there was a very low max miliamp output (like 20mA)...so, practically, step-downs ar ethe only way to go for rock-steady regulation...step-down regulators are generally very efficient also...95%+...the down side to step-down is that you need a high-voltage input so this usually means more batteries (and more size and more weight)...basically the lowest point in the output curve of your power source needs to be equal to or more than your output draw...

lights like the arc-aaa and the ZLT+ circuit are regulators of a sort but they are not perfectly regulated, the output curve mirrors, to some extent, the input curve...

Brock, what you really want is a fuel-cell powered flashlight... (well, i'm sure the rest of us want one too).

Run it about a month continuously on a two-AA tank worth of methanol, refill when done. I think we'll see such a product this decade.

What sort of flashlights does NASA send into space anyway?

I think the PT Matrix is regulated using 2 AA batteries to run 3 leds as well as the new PT Switchback headlamp which also runs 3 leds on 2 AAs as well as running a low output incandescent with a push button switch. There is also a small aluminum one AA powered light with a low output led whose name escapes me at the moment (keychain size). I'm hoping the new SF digitals will run on other batteries besides the CR123. I'm hoping you can put an AA in the 2 battery compartment with the spring taking up the slack or an N cell in the one battery compartment. However, I don't know if this will actually work but can't wait for someone to try it when they come out.

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by hotfoot:
. . . pocket brights and photon 3s. <HR></BLOCKQUOTE>

Where can you get more info on Pocket Brights?

Photon 3's are regulated? I did not know that?

Photon 3s are most certainly not regulated, at least regulated in the sense of putting out a constant or semi-constant output thruout the majority of the batterie's life. This has been proven by my own tests and also many runtime tests with graphs from other posters. Someone just recently posted a pocketbright runtime graph and that appears to have no regulation either.

pocket brights use a resistor, no regulation
Photon 3 and Eternalights have circuitboards to control their functions, but are not regulated.

I guess I'd have to agree that the P3s, the Pocket Brights and eternalights don't attempt (or claim) to maintain full brightness for as long as possible. Yes, at full intensity, both the P3s and the eternalights *do* send full voltage thru the LEDs.

But, does it count as 'regulation' when you use P3s and eternalights in their 'dimmer' mode? Or do PWM circuits only just concern themsleves with modulating/gapping the supply, as opposed to 'levelling' them off as well?

And in the case of the pocket bright - what is that chip there for anyway? If its there for PWM, does that mean that PWM *isn't* regulation(albeit, a different sort)?

This is getting a little confusing - interesting, but confusing...

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by papasan:
...the down side to step-down is that you need a high-voltage input so this usually means more batteries (and more size and more weight)...<HR></BLOCKQUOTE>

papasan,

Can you give me an idea of what voltage you would consider as "high voltage"?

Also, are all these observations about voltage regulation as applicable to incandescent lights as they are to LED's?

Brightnorm

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by Andrew:
Brock, what you really want is a fuel-cell powered flashlight... <HR></BLOCKQUOTE>


I've said it before, and I'll say it again: Batteries are approximately twice as efficient at storing energy than is Hydrogen. The problem rears its ugly head in the "fuel creation" stage. It takes way more energy to separate the Hydrogen to create the fuel for a fuel cell, than it does to shove power into a battery.

I probably didn't say it too well, but with everything we know about fuel cells today, batteries have the efficiency edge by a huge margin.