One 'D' Cell Luxeon Flashlight Mod

Quickbeam

Flashlight Enthusiast
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Re: One \'D\' Cell Luxeon Flashlight Mod

Uh oh! Another Mod website! Well, I suppose my more-or-less monopoly was going to end sometime!

Elektrolumens, once things get going, how about if we create crosslinks to let users check out each other's mod pages?

Looks like a good start. (Maybe you remember my site when it started. Whew! It's come a long way!) Good Luck!
 
Re: One \'D\' Cell Luxeon Flashlight Mod

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by Quickbeam:
Uh oh! Another Mod website! Well, I suppose my more-or-less monopoly was going to end sometime!

Elektrolumens, once things get going, how about if we create crosslinks to let users check out each other's mod pages?

Looks like a good start. (You should have seen my site with it started. Whew! It's come a long way!) Good Luck!
<HR></BLOCKQUOTE>


Hey Quickbeam,

I have been planning for months to get a web site up, and finally did it. I even have started doing some HTML coding. well, actually modifying, really.

Anyway, I think that setting up some links is a good idea. If you tell me what links to set up, I'll put them on my web page.

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Re: One \'D\' Cell Luxeon Flashlight Mod

Looks like a great project. I'll be watching. How many mA will you send through the LS?
 
Re: One \'D\' Cell Luxeon Flashlight Mod

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by jeff1500:
Looks like a great project. I'll be watching. How many mA will you send through the LS?<HR></BLOCKQUOTE>

To tell you the truth, I'm not sure what current a used 'D' cell can generate. I suppose it depends on how much is left in the battery. Of course a fresh 'D' cell could be used. Obviously, some tests for current, voltage, and battery life need to be done, and they will, and will be posted.

Hopefully, I'll get some work done on this project this weekend.

Wayne
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One \'D\' Cell Luxeon Flashlight Mod

Flashaholics,

In response to JonSidneyB inquiry about 1 cell flashlights, I decided to do a project on such a flahlight. I am using a Rayovac 2 'D' cell flashlight, and will replace one of the batteries with a step up regulator. I will modify this flashlight with a Luxeon Star.

So far there are just a few pics of the components before modification. As I progress, pictures will be added. Here is a link to my new website:

ElektroLumens.com

By the way, I am just now learning how to create a web site, and it is just now in construction. I hope to add a lot more pages. Any comments or suggestions would be appreciated.

Also, I might create a web page to put up pictures for those of you who do not have the means, or do not know how to. Just email them to me, and I'll post them for you, with appropriate credits, comments, etc.

Wayne
 
Re: One \'D\' Cell Luxeon Flashlight Mod

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by jeff1500:
Looks like a great project. I'll be watching. How many mA will you send through the LS?<HR></BLOCKQUOTE>

Just finished the MAX757 regulator to be used with the one D cell mod. I used a new 22uH Coiltronics inductor, with a .06 resistance value, which is 50 times less than the .3 ohms resistance with the Miller inductor. The efficiency measurement is as follows connected to a Luxeon Star:
I am using a regulated power supply, not batteries for this test.

Vin Cout Vout Cout eff
2.96 450mA 3.25 340mA 82%
1.268 660mA 2.998 160mA 83%

I'm up from 77% efficiency to 83% efficiency with the new Coiltronics inductor.

Wayne

ElektroLumens.com
 
Re: One \'D\' Cell Luxeon Flashlight Mod

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by Duggg:
I think you mean 5 times less
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By comparison, the handwound M2310 bead core with 2.37 turns requires only about 6cm of #24AWG wire---.006 ohm---which is 50 times less.

Cool web site!
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Hey, your're correct. My math stinks sometimes. If the inductor you're winding is only .006 ohms, that sounds like the way to go.

I wound an inductor this morning, and mounted it on my MAX756 board, and it worked just fine. (I can't get a reading on the resistance of the inductor when it goes below .1) I purchased some bead cores from Digikey a while back. I put 10 turns of #20 wire on it. No idea what the uH value is. If I can get .006 ohms resistance, I suppose I might actually get the efficiency up to 84% or better?


My web site will improve as I learn HTML better. Thanks.

Wayne

ElektroLumens.com
 
Re: One \'D\' Cell Luxeon Flashlight Mod

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by ElektroLumens:
I put 10 turns of #20 wire on it. No idea what the uH value is.

#20AWG copper wire has a resistance of about 0.0004 ohm per centimeter.

Although it's not really important, you can calculate the inductance of a toroid using equations found deep in the Zetex thread.

If I can get .006 ohms resistance, I suppose I might actually get the efficiency up to 84% or better?

I would think so, as loss is loss, and any time you get rid of it, efficiency should go up.
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Re: One \'D\' Cell Luxeon Flashlight Mod

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by ElektroLumens:
I used a new 22uH Coiltronics inductor, with a .06 resistance value, which is 50 times less than the .3 ohms resistance with the Miller inductor.<HR></BLOCKQUOTE>

I think you mean 5 times less
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By comparison, the handwound M2310 bead core with 2.37 turns requires only about 6cm of #24AWG wire---.006 ohm---which is 50 times less.

Cool web site!
 
Re: One \'D\' Cell Luxeon Flashlight Mod

I have done a few initial tests with the MAX757 regulator, and a single 'D' cell battery, and a Luxeon, and I'm not sure if the Luxeon is the best choice for this application.

I used a single 'D' cell, well used, in this test. With .9 volts in, the output voltage from the MAX757 is 2.9 volts, which is not bad, but the current supplied was about 80mA, unless I'm not getting the measurement correct. The Luxeon shines, but not very bright. I decided to use a fresh battery and grabbed a fresher Heavy Duty battery. The input was 1.3 under load, and the output is 3 volts, with 160mA. I'm still not real impressed with the light.

I am wondering if for this application of using up old batteries, perhaps using, say 5 to 8 white Nichia's, as I originally had thought I might use, might be a better solution? Any thoughts or comments here.

Is it still worth using the Luxeon Star, which still might be brighter than 4 or 5 Nichia's, or just use 5 Nichias, (which, by the way, still cost more than the Luxeon.)

I am also considering using a Luxeon emitter, without the optics. It would be mounted in a manner similar to other Luxeon emitter mods on the CPF.

Wayne
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Re: One \'D\' Cell Luxeon Flashlight Mod

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by ElektroLumens:

I used a single 'D' cell, well used, in this test. With .9 volts in, the output voltage from the MAX757 is 2.9 volts, which is not bad, but the current supplied was about 80mA, unless I'm not getting the measurement correct. The Luxeon shines, but not very bright.
<HR></BLOCKQUOTE>

Hi Wayne

It seems you have choosen a very high target with this single cell mod because also with Nichia's you won't have a sufficient brightness at 2.9 volts. Here the results of a measurment I've recently done with 3 different wihite Nichia's:

Code:

Did you ever consider using the Zetex booster for this application?

I just went back to the Zetex thread and found a result recently measured and posted by Duggg:

Code:

It seems that also with this highly optimized Zetek booster circuit the output on only 1 volt input or less is not what you need for a single cell Luxeon Star mod.

Do you remember that Papasan has made a Minimag mod with this Zetex booster switching 3 Nichia's in series? Maybe this way the Zetex booster will bring a better result. I don't know how it behaves in this situation.

Btw, comparing your result and Duggg's result without considering the unknown efficiency of your MAX757 circuit I think your MAX757 booster also works great!
 
Re: One \'D\' Cell Luxeon Flashlight Mod

Hello Remuen, Thanks for your reply.

Regarding the current supplied to the Luxeon, through the MAX757, when I use a regulated power supply, at 1.2 volts in I can get 600mA input, and 360mA output at 3.2 volts. This tells me that there is some sort of limit on the current a alkaline or heavy duty 'D' cell can supply. Can a single alkaline 'D' cell supply 600mA current?

I ran the same test with a LM2621 evaluation board, with a fresh battery. This board is set for 5 volts. The output current was 190mA, at 3 volts. The LM2621, which is a factory made board with optimum design, coult not supply very much more than my regulator. This also tells me that at very best, with a very fresh 'D' cell (heavy duty or alkaline), we could get only 190mA. This is not very good.

The type of battery used here makes a difference. We are not using rechargable batteries, but disposable Alkalines, which cannot put out the current of the rechargables.

I did not use the more recent MAX757 board for this testing, with the lower resistance inductor, for it is already inside the flashlight. I used an older circuit I had.

In my latest design MAX757 step up regulator, I'm at 83% efficiency. I think with a home made inductor I might be able to get the efficiency up even more. However, the homemade inductor will be too big for the one inch disc.

I have a circuit design for the MAX756, which is a 1" X 2" board. It uses much less expensive components, and can use a hand would inductor. It costs me about half as much to make this version (under $10), and it is suitable for a 'D' or 'C' cell dummy.

Remember, the MAX757 regulator has variable voltage, and I can set it to 4 volts for Nichia's.

Wayne
ElektroLumens.com
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Re: One \'D\' Cell Luxeon Flashlight Mod

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by ElektroLumens:

Regarding the current supplied to the Luxeon, through the MAX757, when I use a regulated power supply, at 1.2 volts in I can get 600mA input, and 360mA output at 3.2 volts. This tells me that there is some sort of limit on the current a alkaline or heavy duty 'D' cell can supply. Can a single alkaline 'D' cell supply 600mA current?
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Hi again Wayne / ElectroLumens

I just made a short test with three already used alkaline D cells. They all have about 1.4 volts without load. I measured the short cut current using a 0.1 ohm shunt in series with the ampmeter. All three supplied a current of 1 to 1.2 amp for more than 15 seconds and the voltage acroos this 0.1 ohm resistor dropped down to 0.1 to 0.2 volt. The current limit of a D cell is therefore somewhere between 1 to 1.5 amps.

If you measure the 600mA input current with your DMM then this is only an average current. The peak current - and you have only a peak current with a switcher - could easily be twice as much or even more. Imo an alkaline D cell is not able to supply such a high peak current.

I think a bigger input cap would help to supply the necessary input current. In this case you would possibly need 100 - 220uF (I'm not very good in calculating such things - I prefer the try and error method). Maybe even a bigger input cap would be needed?

Btw, the 83% efficiency are excellent - very close to the one of the highly optimized Zetex booster
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<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by ElektroLumens:

Remember, the MAX757 regulator has variable voltage, and I can set it to 4 volts for Nichia's.
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You can set it but if you can reach it? With the Nichia's you will face the same situation as with the LS if they need the same current. But if you use only 5 Nichia's and drive them with 30mA you need only 150mA. But in your case you reached only 80mA on 2.9 volts. I would give it a try and look what happens.

Good luck!
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Re: One \'D\' Cell Luxeon Flashlight Mod

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by remuen:
You can set it but if you can reach it? With the Nichia's you will face the same situation as with the LS if they need the same current. But if you use only 5 Nichia's and drive them with 30mA you need only 150mA. But in your case you reached only 80mA on 2.9 volts. I would give it a try and look what happens.

Good luck!
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Considering the input capacitor and the output capacitor, I think the output cap is more crucial. I will experiment a bit with larger values for both input and output caps.


With a fresh 'D' cell, I did manage to get 160mA out, at around 3 volts out. But the idea of this project was not to work with fresh batteries, but to be able to use up 1/2 used batteries in a solitary configuration. We have to keep this in mind in designing this flashlight.


Wayne
ElektroLumens.com
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Re: One \'D\' Cell Luxeon Flashlight Mod

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by ElektroLumens:
I am using a Rayovac 2 'D' cell flashlight, and will replace one of the batteries with a step up regulator.
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Are you aware that Rayovac has changed their 2 'D' cell Industrial flashlight? It now contains a three LED battery meter in the head. Green if the battery's good, yellow if it needs replaced soon, and red if the battery is about dead; like the Sears flashlights. They're available now at Home Depot.
 
Re: One \'D\' Cell Luxeon Flashlight Mod

akkk
putting a 15$ led in a 2$ light
and all that work tooo
ya got drive lumens :)
 
Re: One \'D\' Cell Luxeon Flashlight Mod

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by Video Guy:
akkk
putting a 15$ led in a 2$ light
and all that work tooo
ya got drive lumens :)
<HR></BLOCKQUOTE>


Actually, the flashlight is the Rayovac Industrial. It costs between $6 and $7. Yes, it's plastic. I have chosen this flashlight because of the design, the battery compartment is separate from the head compartment, and is very easy to modify. This is also a very tough flashlight.

You're right though, a $14 or $15 dollar Luxeon Star, a dc/dc regulator costing me around $18, all stuffed in a inexpensive flashlight. And all that labor! Kind of eccentric, huh?

Wayne
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Re: One \'D\' Cell Luxeon Flashlight Mod

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by Empath:
Are you aware that Rayovac has changed their 2 'D' cell Industrial flashlight? It now contains a three LED battery meter in the head. Green if the battery's good, yellow if it needs replaced soon, and red if the battery is about dead; like the Sears flashlights. They're available now at Home Depot.<HR></BLOCKQUOTE>

Hmmmmm, no, I wasn't aware of the change. Sounds interesting.

My older version also has a meter. When the batteries are good, the light is bright white, when the batteries get low, it turns yellowish, and when the batteries need replacing, the light doesn't shine.

Wayne
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