Voltage regulated flashlights.

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by X-CalBR8:
... the importance of voltage regulation is greatest with Alkaline batteries ...

... Lithiums are very nice no doubt, but I don't think they will ever come close to comparing to alkalines price wise.

... I can go to Wal-Mart and buy a 20 pack of alkaline AA's for what it would cost me to buy a couple of lithium 123's. That is a tenth of the cost! That is quite a significant difference in operating cost. I'm curious to know what everyone else thinks of this. Am I the only one that is much more concerned with operating cost than the up front cost of the flashlight?
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X-CalBR8, you're not the only one. That's why I have changed to LED flashlights for general use - mainly the ARC AAA LE which has such a regulator in it.

I'm now working on a own booster/stepup converter which could be used eg in a Minimag mod (for driving LED's) but also in other flashlights.

IMHO an important point that incandescent flashlight do not have voltage or current regulators is, that the power consumption of incandescent bulbs is often much higher than with LED's or a Luxeon Star. That makes it more difficult to make a good and efficient DC-DC converter.

But it would obviously be great to squeeze all alkalines down to the last drop of energy like I can do it with the great tiny ARC AAA. See here how such a booster circuit could save your money: How an ARC AAA runs on a low battery
 
I for one would love to see a regulated incandescent light. I hate running a light for 5 minutes and see the yellowing effect already starting to show in the beam. HELP PETER!!! u da man...An ARC LSSD incandescent SUPER DUPER AA.
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LEDs will light, albiet at a low level, with very little current, so it's not true to say you could get the performance of the arc-aaa's 'moonlight' mode (which, i think, is just the point were the inverter is shut off and the LED is run directly off of the battery) out of an incandecent...an incandecent with a voltage regulator would be nice, it would keep the bulb at a constant current and therefore prolong it's life and you could get the discharge curve of lithium batteries out of alkaline's, but LEDs and incandecents are different beasts and the results wouldn't be the same...
 
Glow Bug: I couldn't agree more. Why replace alkaline batteries before they are absolutely, completely, all the way, beyond all use drained, when with an inexpensive inverter, you could drain batteries down to close to .5volts instead of the usual 1.X-volts. Like you said, it would be worth having the inverter simply for purposes of light quality if nothing else. Most incandescent bulbs that I've ever seen, even after less than 15 minutes use, already start to dim and yellow.

I, for one, would be willing to sacrifice total runtime for a better quality white (no yellow) light. I really don't think there would be this great reduction in runtime that everyone fears from the marginal amount of power used by the inverter, because of the simple fact that you will get more usable light with a VR than without one because you can get much more useable life from a battery that you couldn't get without one. Just imagine taking your batteries down to .5volts or thereabouts, instead of the usual 1-volt with most flashlights. And not only that, but as the flashlight approaches that dreaded 1-volt mark you are stuck with a very poor quality of light and a very reduced throw of light and isn't the main point to using an incandescent over a LED light to get that long throwing light that current LEDs just can't seem to muster? Just some more food for creative thought.
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<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by X-CalBR8:
mrchri5: I agree. Why turn to Surefire et al to do the job when we have one of the finest flashlight VR engineers on the planet, namely Peter Gransee. How about it Peter? How about a high quality, high output, voltage regulated, incandescent flashlight to add to the Arc line? I, as well as, I believe many others on the board, would be very interested in such a project.

I mean, even if there is a loss involved in the VR, who cares when you are paying one-tenth the price for the batteries? I just don't know, this just seems so clear to me that this would be a great idea. I really don't understand why there is so much resistance to this idea. More than that, I don't understand why no company has ever made such a high-output VR flashlight in the past, unless it was a cost issue (which it should no longer be) or they were just worried that no one would be willing to accept something new. Perhaps, considering the negative comments so far, the latter would be the primary reasoning behind the lack of such a flashlight. Hmm…
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X-CalBR8, Just came across this thread. If I may..

A VR lithium SF would be a case of diminishing returns in my opinion. The incandescent/lithium setup already provides a flatter than normal discharge. Adding a VR would make the discharge even flatter, but it might not be noticeable in the target applications of the SF (short duration tactical). Add to that the losses of the VR (5-15%) and the extra cost (30-50%) and the VR SF would no longer meet its target market as effectively.

True, VR would improve the bulb life somewhat. But those gains are modest in comparison to the upfront and ongoing costs of the VR system.

Since a lithium battery typically provides less light for your flashlight dollar, it is less suited for everyday use. The rechargeable SFs are more cost effective for everyday duty compared to lithium SFs.

But rechargeables are only best for a limited set of applications. Alkaline are superior in general use. Alkaline provide longer shelf life, longer mission endurance (or brighter) and faster 'recharge'.

Of course, a versatile flashlight will use all three types of battery and leave the choice to the user.

As you know, one of the problems with alkaline is that is difficult to retrieve most of their capacity. A typical incandescent is 'dead' when the cell voltage reaches 0.9 volts. But at 0.9volts an alkaline AAA cell still has 40% capacity remaining. It gets even worse as the cell size increases to a 'AA', 'C' or 'D' cell.

Notice how most mAH ratings for alkaline only measure to 0.9volts. So there is 40% more capacity beyond the mAH rating of the cell.

Besides a flatter discharge, a VR is able to capture more of the alkaline's lost capacity. For example, the Arc-AAA with its inverter/regulator is able to maintain 80% light output with 40% remaining capacity in the cell (80% output at 0.9volts under load). It continues to illuminate well past 0.9 volts. The end result is the cell is quite dead afterwards.

So to answer your question, yes, an alkaline powered incandescent would certainly benefit from a VR.

Why doesn't Arc make a VR incandescent? We believe LEDs are the future. True, usually incandescents are brighter than LEDs. But that will change with time. That is why we are focusing our research dollars on LED technology.

Btw, LEDs especially benefit from VR (alkaline considerations aside). As the voltage across the junction drops, the amperage consumption drops even faster (compare to incandescent above). This makes it even more difficult for a non-regulated LED flashlight to usefully capture all the battery capacity.

Peter Gransee
 
I understand Peter's viewpoint and expected he would say that (but thanks for responding), and also agree with his Surefire assessment. However, I would think SOMEONE would make a VR incandescent flashlight. When my Surge gets dimmer then my E2 then I feel like dumping all eight batteries even though there is life left.

Peter, if you're still reading this thread, is a regulator for a flashlight that difficult to produce? Say you desired a constant five volt output, could you just use a 7805 IC or is it more complicated then that, ie you need something that feeds the output back into the input for monitoring purposes similar to how a switching power supply maintains its constant output.
 
I sure wish it was possible-read: practical, (bcos of prohibitive shipping cost) to get my hands on all those tired old alkalines you guys have laying around...9 out of 10 of 'em I can "recharge" to about 90% as good as new, (for probably 4-5 more cycles under average use), in just a few hours....They will put out a good strong jolt/current under heavy loads too....
I'm still using alkalines that I bought in '93-'94, and I can't throw them out, because they still work nicely!
-And that DOES mean powering up incandescents
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<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by geepondy:
.......However, I would think SOMEONE would make a VR incandescent flashlight.........<HR></BLOCKQUOTE>

...so isn't that the Willie Hunt circuit as found in the EasterSeal Headlite lll? Has 4 brightness settings too...
 
I have a great new switching regulator I will share you all of you when I am finished building it. I am just finishing putting on the finishing touches. But, I need some suggestions for the final setting.????
What would be a good voltage to set a 3.6 volt Krypton bulb if a switching regulator was used. Maybe a littler higher (3.7 volts) to maker it brighter, or a littler less (3.5 volts)to make it last a little longer. Please let me know your thoughts. Greatly appreciated.
 
Hi Peter. I'm very pleased that you noticed this thread and decided to take part in this discussion. Let me just start by saying that I totally agree with you when you say that LEDs are the way of the future. I would like to state that I fully believe this as well. The only problem being that for at least several years (and perhaps many years) to come LED technology just simply won't be up to the challenge of matching an incandescent for "Long Throw" types of applications where you need to see something far off such as spotting a far off animal or a criminal. This is why I believe that there is such a strong need for such a high-quality VR flashlight, to fill in till LED technology is completely up to the task of taking over ALL incandescent functions (not just close to midrange functions). I had really hoped that you would take up the gauntlet because of your great experience in these matters. I know that you could very probably produce the best VR flashlight on Earth if you were to set your mind to it and it saddens me that you do not wish to take up the challenge, but at the same time, I can understand where you are coming from because I've been reading your post concerning the Arc LS and all of the time that you've had to invest in it. I sure hope that you can get the bugs worked out soon so that you can put that great creative mind of yours to other projects as well. BTW, I can't wait to try out a LS once you get the bugs worked out. The screen shots look very encouraging. I would also like to mention that I'm enjoying my Arc LE very much and if there are any of you out there that haven't had a chance to try one out yet, then you are really missing out on the most advanced AAA flashlight on the planet (at least that I'm aware of).
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So, where does this leave us now? Does anyone else care to take up the challenge of creating a high output VR flashlight? Just imagine the sort of light output of a Surge, but voltage regulated to keep it at top brightness till the very last drop of power is sapped out of the batteries. Will this just remain a dream forever or will someone actually pull it off?
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davo123: I'm very pleased to hear that someone else is interested in creating a circuit for a VR incandescent flashlight, but I'm just curious, is there any way that you could be encouraged to think bigger than 3.6 volts? I know that we are talking about considerably more wattage than we are used to in creating circuits for LED applications, but I was thinking along the lines of a 9 or 12 volt incandescent. At a very minimum it would need to be 6 volts because that is what is put out by my 4D MagLite and I consider that to be the bare minimum of what would be acceptable for a "long throw" incandescent. It would also have to be at least 6 volts to put it anywhere near the neighborhood of a Surfire or a Surge also. I think a 8 AA 12 volt VR flashlight would be about the pinnacle of what could be accomplished with a small handheld. This would put it on par with a Surge and that seems to be a very nice amount of light. I believe that if the circuit is small enough to fit in the head or the Tail of a 2D MagLight that you would have about the most awesome flashlight for it's size that I can imagine (that would be feasible). Or, like I started trying to build a while back and could never seem to get all the parts together, do it all in a 3D MagLite and put the circuitry in a D Dummy Cell. The only thing standing in my way of pulling of this greatest flashlight mod of all time is a viable Step Up circuit that can handle that kind of wattage and still be efficient. I know it can be done. It's not theoretical. The technology is out there to pull this off. I was just hoping that it could be done this year because if it isn't done soon then hopefully I will soon have the necessary engineering skills to draw up the plans and do it myself. I will be starting the hard-core electronics classes in college this fall and hopefully have access to the necessary lab equipment to work easily with surface mounted stuff. I really believe that SM is the only way to go because of the space limitations involved with such a project. I was just thinking, surely there are some excellent Electrical Engineers lurking on the board that deal with such trivial circuits every day. Why not join in the fun and help us out with a circuit?

Davo123: I'm very interested to hear more about your circuit. BTW, are you a full fledged Electrical Engineer, or just an electronics hobbyist such as myself?
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I am producing a 2D flashlight with the newest VR chip with anticipated efficiencies at +95%. Im fishing now for the best voltage to set for a 3.6 volt krypton bulb. I'll will have samples of the light for sale soon.
 
To X-CAL:
We can make any voltage output happen. The best approach to maintain the highest efficiencies is to set the bulb voltage about 1-2 volts over the battery voltage. Emample: 2x1.5=3.0 volts and should use a VR boost VR to a 3.6 volt bulb. So, 3x1.5=4.5 volts to power a six volt bulb should be no problem. I still need lots of input and suggestions. This is new stuff and we are the first to make it happen. Let me know. I need to know the exact voltage setting for the VR output. Give me some numbers.
Take care.
 
davo123: If I were you, I would definitely overdrive the bulb a tad rather than underdrive the bulb. What tiny bit you loose in bulb life, you will gain by a stronger more purely white light that will be much more useful. If you underdrive it to make the bulb last longer then you are defeating one of the purposes of putting a VR in a flashlight in the first place. That is to keep the bulb at full brightness so that it is perfectly white and not yellowed or muddy brown at all. BTW, I can't wait to see your results. This is a topic that I am VERY interested in and can hardly believe that so little has been done in this field till now.
 
I would really like to see a circuit small enough to fit in a dummy D cell and kick 3volts up to 4.5 so that I could put the circuit in a dummy D cell in a 3D MagLite and run it on 2 D rechargeables and always have a perfect full brightness light from it. Or do the same trick on my 4 D Mag. Kick the 4.5volts from 3 of the 4 D batteries up to 6 volts and put a dummy D cell (with the circuit in it) in my 4D Mag. I would even be inspired to get a 5D Mag just so that I could load it up with 4 D batteries (I like to keep them in even numbers for obvious reasons) and then put in the dummy cell in the 5th position. I'm getting excited just thinking about it. Hehe.
 
That would still warrant having a regulated one in my opinion. I would pay the extra cost to have a steady output instead of wishing you had a new set of batteries when the ones that are in the light could give you better light output with the regulator.
 
Or kick the voltage from 1 C or D cell (in a 2-cell light) up to 3.8......the possibilities are endless here...why not AA or AAA "dummy inverters" also....there are lots of 2-cell lights out there.
 
I also thought it would be a neat possibility to take a 4D MagLite (which I happen to have) which is 6volts and double the voltage to 12volts. I know there would be a pretty big loss with kicking the voltage up this high, but it would open up a world of possibilities because there are a LOT of 12volt bulbs to try out because that is the voltage of a car battery. I'm not sure how to figure up how bad the losses would likely be, but I suspect that most losses would be recovered by the fact that you could run the batteries down to around .5volts instead of the normal 1 volt. Also it is worth noting that 12volt bulbs are more efficient than smaller voltage bulbs and 12volt bulbs almost always have a MUCH longer time before failure than smaller voltage bulbs. That neat little fact means that you could kick the voltage up by an extra volt or 2 to say 14volts and get a super bright light saber of a light and still not have to worry too much about blowing the bulb in a short amount of time. This seems to me to be a very logical route to take. What do you guys think?
 
<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by X-CalBR8:
I also thought it would be a neat possibility to take a 4D MagLite (which I happen to have) which is 6volts and double the voltage to 12volts. I know there would be a pretty big loss with kicking the voltage up this high, but it would open up a world of possibilities because there are a LOT of 12volt bulbs to try out because that is the voltage of a car battery. I'm not sure how to figure up how bad the losses would likely be, but I suspect that most losses would be recovered by the fact that you could run the batteries down to around .5volts instead of the normal 1 volt. Also it is worth noting that 12volt bulbs are more efficient than smaller voltage bulbs and 12volt bulbs almost always have a MUCH longer time before failure than smaller voltage bulbs. That neat little fact means that you could kick the voltage up by an extra volt or 2 to say 14volts and get a super bright light saber of a light and still not have to worry too much about blowing the bulb in a short amount of time. This seems to me to be a very logical route to take. What do you guys think?<HR></BLOCKQUOTE>

The real life example we have is the Infinity LED light, and the excellent regulated example of the ARC AAA. Let's not forget though, the reason for the stepping the voltage up is due to the requirement of the LED to have at least 3.6 volts. It is not to increase the power. Regardless of whether you're running 6 volts or 12 volts, you're still only able to suck a limited amount of power out of the cells at any given time. The relationship for power is volts X amps. You can double the volts, but you're going to half the available amperage. There's no free lunch.

Stepping up the voltage is fine when it's a requirement of the component, and the potential of the power source is insufficient. But, if more power is required than the source can provide, the only way to get it is to add more power.

I am supporting though, of regulating enough to fully use a primary cell, rather than wasting the majority of it's capability.
 

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