Regulated LED lights

It appears that regulated LED lights are preferred by CPF. Its something that I am looking for in a flashlight now also. I notice that the well regarded Pelican M6 is "not regulated" which is the sole reason why I have not yet bought one.

I see the UK 4AA eLed is regulated for only $20 - therefore, I'm beginning to wonder if regulation is going to become the norm - therefore stocking up on unregulated lights at this time may be waste. Any thoughts appreciated.

Hmm... whatcha gonna do with all those used batts from your regulated lights then? I was just going thru my used 123s a couple days ago, these were too weak to power both my KL1 and LS anymore. Tried a few in my X5t, and surprisingly decent amount of light still comes out of it. Its a real sucker I tell you...
What'll we do w/out unregulated lights? /ubbthreads/images/graemlins/icon3.gif

The M6led is a 123-powered light and 123's discharge curve is flatter than alkaline cells, so the regulation doesn't do as much to keep the output steady. On the other hand, there's considerable resistive loss in the M6led.

Regulation means you get steady output through the battery runtime, and sometimes can be more efficient a than resistor-limited light. But there's more stuff in the light, so more things can go wrong. Also, a regulated light will run to a certain point then basically cut out. An unregulated light will have slowly declining output for a very very long time.

I'm not sure what your concern is about "stocking up". If the lights you get fill your requirements, then what's the issue?

Both regulated and unregulated lights will be with us for a long time.

though i really like my regulated lights, i find a certain comfort in unregulated due to it's slow dimming.

Bob

The run time plots that KJ has posted are rather telling.

Here's unregulated [/url and here is the same basic configuration [url=http://www.obaq.tv/cpf/images/PM6-DB700-TV1K-2x123-Ventilated_Runtime.png]regulated.

As you can see, the unreguated and regulated dropped to 1/2 brightness at 90 minutes. The regulated spent that whole time at 2500lux but the resistored unit fell below 2500 lux after 12 minutes. Nowwhere on the graph is the resistored unit brighter.

The regulated light drops from 2500 lux at 90 minutes to 500 lux at 170 minutes. The unregulated light drops from 1400 at 90 minutes to 400 at 170 minutes.

In this particular case, my interpretation is that at 700ma drain, the downboy does a great job of getting as much energy as possible from the batteries and the TV1K LED does a great job of converting it to light.

I happen to have an M6 LED with the downboy and McModule. It's only 45 lumens but I love it. I've not gone through the first set of batteries.

Daniel

which is better for running down used 123s from SF?

regulated or unregulated?

particular model? LED vs LS? /ubbthreads/images/graemlins/smile.gif

STockaw92 asked... which is better for running down used 123s from SF?




I don't know. You want it bright or do you want it to glow dimmly forever? It looks like both go direct drive after the voltage drops too low. The resistor may make the direct drive less efficient at this point.

Daniel

i guess at least some what bright, as bright as a CMG Sonic/Ultra/Arc AA/Arc AAA?

I really meant....

It depends on too many factors unless you buy a regulator that specifically boosts from such a low voltage that rechargables might be damaged. If it goes direct drive at a low voltage then it depends on the characteristics of the specific LED.

I've only experimented with a few different converters (4 or 5) and only the wizard (a buck/boost converter) stops powering the LED completely when the voltage goes below a set point. The rest go into direct drive. The wizard would do a good job of protecting rechargables.

So if it's dropped to direct drive mode in a low resistance way, it will be brighter longer than a unit with a resistor designed to limit the current when you have full battery power.

Daniel

Daniel

Hahaha... Yet another power miser. /ubbthreads/images/graemlins/hahaha.gif To extract the last dregs of energy from a cell, any cell, you shouldn't be looking be looking at commercial lights. They work alright, but their primary design is to produce as much light as possible.

Do searches on Milkyspit Candle, joule thief, SatCure circuit and regulated SatCure. Especially regulated SatCure. IIRC, the Milkyspit candle is a resistored design utilising 2 CR123 cells to power a single 5mm LED. The Joule Thief and SatCure circuit (essentially the same thing) are unregulated boost using a very simple flyback design and a single 1.5V cell. It can drain the cell to 0.7V, which is the bare minimum needed to make the transistor work. The regulated version has an extra transistor to "throttle back" the output. I have found that it doesn't really regulate, but the throttle allows up to 3V input to be used.

But perhaps the easiest is to build a light using the MicroPuck. It is a relatively efficient unregulated boost that works between 0.7V and 3V, designed to power a 1W LS. I have found that it will still run off a CR123 discarded from my KL1, though the brightness is about 2-3 times the CMG Infinity Ultra.

Hmmm... looking at my answers, I guess the proper answer is "unregulated", or perhaps, semi-regulated where semi-regulated is like the Arc-LS which goes out of regulation when the input voltage drops below a certain point, but the circuit is still able to operate and boost the voltage to a useable level to light the LED.

hmm, joule thief is the way to go IMHO /ubbthreads/images/graemlins/grin.gif

if you want to drain the batt till the end, MP is not really a good idea as it drains too much current and the battery won't be able to supply the current when it is already become so depleted.

beside, for such low current consumption, led performs MUCH better (more efficient and brighter) than luxeon.

where can i get those??

i searched and can't really find info on it?

can anybody help me out? thanks

[ QUOTE ]
Steelwolf said:
IIRC, the Milkyspit candle is a resistored design utilising 2 CR123 cells to power a single 5mm LED.

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Actually not. It uses a true constant current regulator with a switch to set one of three levels (about 30 mA, 8 mA and a bit less than 2 mA). It's rock stable down to .1 Volt above Vf, where it goes to 'direct drive'.

Doug Owen

[ QUOTE ]
shiftd said:

beside, for such low current consumption, led performs MUCH better (more efficient and brighter) than luxeon.

[/ QUOTE ]

Really? In my modest testing I found just the opposite. On what do you base the statement?

In fact right now I'm looking at a 'rare S bin Nichia' and a typical LS low dome emitter, both at 30 mA. The LS is the clear winner. Likewise at 8 mA.

FWIW, I think the typical experience is underdriven LS emitters give more Lumens/watt than 5 mm parts.

Doug Owen

Regulation is much more effective with Alkaline battery based light, than with Lithium based lights.

Yes lithium based lights, like the Pelican M6 will start out a little brighter, and dim slightly over the life of the batteries, but from the begining, to almost the very end, the light is very bright, and only at the very very end, does the light dim.

Also, remember, that, even though regulation is getting more and more efficient, there is an efficiency loss in implementing regulation.

[ QUOTE ]
BuddTX said:
Also, remember, that, even though regulation is getting more and more efficient, there is an efficiency loss in implementing regulation.

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Very true. Nothing's free. Still, you can get some pretty impressive numbers if you're careful. As I'm found of pointing out, 3 NiMH (or NiCd for that matter) cells is an excellent match for typical 'white' LEDs. The battery is only a few tenths above Vf, a low drop out regualtor can run on a part of that. Say .2 or .3 Volts typically (remeber the NiMH is pretty flat discharging) out of 3.6, 90% efficiency is easily possible under controlled conditions.

Doug Owen

Buddtx wrote:
lithium based lights, like the Pelican M6 will start out a little brighter, and dim slightly over the life of the batteries, but from the begining, to almost the very end, the light is very bright, and only at the very very end, does the light dim

While true in some cases, I've seen different results. Here is the runtime of a 2 cell (2x123a) luxIII


and the same basic configuration with a downboy



The plots clearly show the resistor'ed light has a constant loss. This could be due to the high current drawn from the batteries.

I've seen the same kind of drop-off with my Inova X5. It was getting dimmer over the course of several week, but I didn't realize it until I could not see things that I should be able to spot. That explained why no-one was wow'ed by my nifty light after only a few weeks. Fresh batts and BAM! it was like new.

I'll go with regulated PLUS lithium whenever I can.

Daniel

Many many thanks to all who responded to my original question. Lots to know and lots to think about. Again, many thanks.

[ QUOTE ]
gadget_lover said:
Nowwhere on the graph is the resistored unit brighter.


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Generally, I think this is all you need to know about regulated vs. resistored.