# Help identifying parts for homemade light



## thumpergirl (Apr 25, 2014)

I posted under the LED Flashlights thread but it might have been the wrong place to post. I'm looking for 1 or 2 things: 

- help understanding and identifying parts to mimic a homemade flashlight, or
- some awesome and extremely knowledgeable and competent new best friend to build it for me (after telling me what parts and where to get them, and I'm not sure if it's allowed or not but I would be happy to compensate you)




waterproof (I can use heat shrink and silicone to finish that job)
single mode
must run about 12 hours on 1 external battery pack, a 10 pack of AA lithiums (~15V)
no on/off switch, turns on when plugged into battery pack, off when unplugged
since the battery is not internal, I need two lead wires coming from the emitter and not the usual coil thing for battery contact


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## thumpergirl (Apr 25, 2014)

Can I take something like this part:

then remove the coil thing, unscrew the base module, solder lead wires to the LED emitter (once I know what to get), put the emitter in there (don't know how), and then connect those lead wires to the driver, once I know what driver to get)?


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## RepProdigious (Apr 25, 2014)

You are on the right track, but ive posted a link to a pre-built unit in your other topic.


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## DIWdiver (Apr 25, 2014)

That part you posted has no LED or driver. It would work if you bought them separately.

How about this? It has everything you want, I think.

http://www.dx.com/p/cree-q5-led-drop-in-module-3-7v-18v-input-11621#.U1r6yfldV8E


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## Ken_McE (Apr 27, 2014)

You are trying to duplicate something you don't understand, using parts you can't identify, and techniques you are not familiar with. You want to do it in a hurry too. I think your expectations are a little too high. If you want to build a light, that's reasonable, we can walk you through it. If you want to understand a light we can help do that too. I have however some doubt that we can teach you fast and reliably enough to make something that sophisticated by your deadline.

Would you consider buying a cheap light and just duct taping it to the front of your boat?

Once the immediate problem was out of the way you could study/shop for a more perfect light at your leisure. Failures and missed deadlines would not be an issue. You wouldn't have to compromise on anything. By the next race after this one you'd be properly ready, and you'd appreciate it more after suffering along for a race or two with some cheap Chinese Wimp-O-Matic.


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## thumpergirl (Apr 27, 2014)

Ken_McE said:


> You are trying to duplicate something you don't understand



yup



> using parts you can't identify


yup



> and techniques you are not familiar with. You want to do it in a hurry too.


yup




> I think your expectations are a little too high.


unfortunately, i cannot argue with this. i would if i could, but i can't.



> If you want to build a light, that's reasonable, we can walk you through it. If you want to understand a light we can help do that too. I have however some doubt that we can teach you fast and reliably enough to make something that sophisticated by your deadline.


i gotta agree with this, too. my deadline sucks! but a little history - i didn't procrastinate, one of my teammates had an injury, which required me to enter solo, thus a different hull, different configuration, etc... i figured the chances were slim, but i also had to try. i was really hoping it would be as simple as finding the right host, the right drop-in, the proper tail cap, the cable gland, and putting it all together rather neatly. turns out, as i now know, it's not quite that simple. 



> Would you consider buying a cheap light and just duct taping it to the front of your boat?


i can't bet a 72+ hour race of this magnitude with a cheap light and some duct tape. i don't wanna swim in the dark with gators and water mocassins. the thought of that is a little scary to me. i need a reliable light. not sure yet exactly how I'm gonna get that but I'm making progress, anyway.



> Once the immediate problem was out of the way you could study/shop for a more perfect light at your leisure. Failures and missed deadlines would not be an issue. You wouldn't have to compromise on anything. By the next race after this one you'd be properly ready, and you'd appreciate it more after suffering along for a race or two with some cheap Chinese Wimp-O-Matic.


This is my plan. Even if I get someone to build a light for me this time around, I need to know how to do this so I'm not stuck in this same predicament in the future. So after the race, I'll be dedicating time to building some of these units myself. So honestly, these are perfectly valid questions and suggestions you have. I completely understand that my requests seem a little hasty and maybe far fetched.  I appreciate all of the different responses I am getting. I'm sure I'll get something worked out for the short term, and learn a lot about building something for my next races.


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## Mr Floppy (Apr 28, 2014)

The connector out to your battery looks like a SAE connector. 

The hole at the back looks like the switch hole for the 503B so finding a cable gland to fit that should be easy. In terms of the internals, I would just get a new 503B and soldering wires to the head, partially disassembling the P60 pill.


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## thumpergirl (Apr 28, 2014)

Mr Floppy said:


> The connector out to your battery looks like a SAE connector.
> 
> The hole at the back looks like the switch hole for the 503B so finding a cable gland to fit that should be easy. In terms of the internals, I would just get a new 503B and soldering wires to the head, partially disassembling the P60 pill.



Can you tell me a little about disassembling the P60 pill? Can I just take the coils off and solder the wires there, or do I need to take the pill apart?


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## Microa (Apr 28, 2014)

Please read this thread which explains the structure of the P60. http://flashlightwiki.com/DIY_P60 Do you know how many energy of your batteries have and the power you are allowed to consume for 12 hours?


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## thumpergirl (Apr 28, 2014)

Microa said:


> Please read this thread which explains the structure of the P60. http://flashlightwiki.com/DIY_P60 Do you know how many energy of your batteries have and the power you are allowed to consume for 12 hours?



~16V, a 10 pack of AA lithiums wired in series. 

Thank for the link to the wiki, that's a good read!


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## DIWdiver (Apr 28, 2014)

Microa said:


> Do you know how many energy of your batteries have and the power you are allowed to consume for 12 hours?



3000 mAh at 15V.


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## Microa (Apr 28, 2014)

OK. You will have some idea what we are talking about.
Your first photo shows a P60 drop-in without driver. The red and black wires are the connecting wires to the LED+ and LED- which are now connected to a 300mA step down driver's output LED+ (the thick red wire) and LED- (the thick white wire).
These drivers are designed for MR16 or MR11. They can accept AC or DC input. Apply power to test your system. Your homemade light is almost done.


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## Mr Floppy (Apr 28, 2014)

thumpergirl said:


> Can you tell me a little about disassembling the P60 pill? Can I just take the coils off and solder the wires there, or do I need to take the pill apart?



You will need the spring to keep the P60 head water tight in the 503B but you could solder the wires directly to the contacts if you like. You probably don't need the inner spring, the positive one.


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## DIWdiver (Apr 28, 2014)

Excellent suggestion on a driver, but can you be more specific? What bulb to dis-assemble, and where to get it, or where to get the driver by itself?

MR11 and MR16 bulbs are usually well over the target of 1W. Any idea how to get one that's closer to 1W?

I suppose a driver like that is likely to be easier to modify to get the exact output you want than a dropin is, just because you wouldn't have to open up and close back the dropin, which can be a pain in the butt. It's also more like her original light than a dropin would be.

Okay, I did a quick look on DealExtreme, and found this, which should be pretty much the perfect driver. It even includes reverse polarity protection, even better it can work with either polarity as it can handle AC input. http://www.dx.com/p/mr16-1-1w-320-3...ted-led-driver-8-40v-input-13553#.U18UkvldV8E.

Given thumpergirl's timeframe and resultant desire to order in the US, anybody got suggestions where to get one in the US? Is a bulb like that available at Home Depot?


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## Microa (Apr 28, 2014)

The 3 LEDs of the 3W MR16 bulb was connected in series which driver is suitable to drive a single LED at 300-350mA. For MR11, only the 1W driver is suitable for your need. Otherwise, the light consumes more power that it can not sustain for 12 hours.
Further to the basic system, you should consider the heat management and the waterproof if necessary.


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## thumpergirl (Apr 29, 2014)

Microa said:


> The 3 LEDs of the 3W MR16 bulb was connected in series which driver is suitable to drive a single LED at 300-350mA. For MR11, only the 1W driver is suitable for your need. Otherwise, the light consumes more power that it can not sustain for 12 hours.
> Further to the basic system, you should consider the heat management and the waterproof if necessary.



OK I think we're on the right track here. I know the guy that made the light had to do something special to make it last that long on the batteries. I'm trying to follow all of this but I'm missing too many pieces. 

So, I buy a reflector, a LED emittor, and a step down driver to make the light consume less power and last longer on the battery pack. 

Does the light output the same lumens? 

How do I know which emitters will work with the driver that DIWdiver found? (thanks, DIW!)

Also, regarding heat, doesn't the p60 aluminum host act as a heat sink?

I've already purchased a couple of drop-ins that are in the mail. If I just do a drop-in, will it drain the batteries too fast? I'm assuming so, and that is why we are looking at a step down. 

Can you help point me to exact parts I need to assemble? I'm afraid I'll purchase the wrong step down, emitter, etc... I have a solarforce l2p on the way for a host, and some cable glands. If you could point me to right step-down, LED, and whatever else I'm missing, that would be very helpful. 

I think we're on to something here!


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## thumpergirl (Apr 29, 2014)

Also, will using this step-down driver give me a significant boost in performance (battery conservation and lumen output)? 

I don't understand the LED MR11 and MR16 LED bulb. They don't appear that they'd fit in a p60 host. And why are there 2 metal pieces instead of lead wires coming out of the step-down driver? Not sure how to make that work.

Sorry for the remedial questions. This is a lot to ingest.


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## Microa (Apr 29, 2014)

The solarforce L2P is a 18650 li-ion battery powered flash light. I thought the original driver is not suitable for your need. I measured the width of my MR16 step down driver is 18mm just fit into the L2P body. Don't forget to insulate the driver to the body to prevent short circuit ( I don't know the inside of the body was anodized or not ). 
The lumens output mainly depend on the type of LED, the bin ( lumen output grade sorted by the manufacturer ), the driving current and the operating temperature of the junction of the chip. Suppose you have purchased an XML T6 solarforce L2P, 1W MR11
driver is about 300-350mA driving current. So you can check with this design tool http://pct.cree.com/dt/index.html While the junction temperature at about 85C, the lumens output is about 108 to 125 lumens.
The solarforce L2P is designed for 3W up LED, I thought it should be able to dissipate the heat properly.


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## thumpergirl (Apr 29, 2014)

Is the step-down in addition to the driver that's in the drop-in, or is it a replacement for the driver that's in a drop-in?


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## Microa (Apr 29, 2014)

The power supplies to the MR16 bulb through a bi-pin socket. So the driver's inputs are soldered to two pins. The other two wires are positive output and negative output to the LED. You don't need these 2 metal pins. Desolder them from the driver board.

The driver is to control the current going from the battery to the LED. Higher current will boost the lumens output and at the same time it consume more power of the battery.


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## Microa (Apr 29, 2014)

Replace the driver in the drop-in with the MR11 's one.


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## Microa (Apr 29, 2014)

If you don't consider waterproof the light, why don't you direct power the 1W MR11 by the battery?


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## thumpergirl (Apr 29, 2014)

Microa said:


> If you don't consider waterproof the light, why don't you direct power the 1W MR11 by the battery?



I do have to waterproof it; it will be used in the river and in a very windy bay. Last year it was submerged in the bay for periods of time as the waves went over the boat, and the same will likely happen this year.

OK, so i can use the drop-in I ordered, open up the pill and remove the driver. Then strip the step-down driver out of any M11 or M16, and solder that in place of the drop-in driver. Then wrap it all up in a p60 host and waterproof the whole thing, and voila? 

Do I need to pay attention to the lumens and voltage from both the MR11/MR16 and the drop-in? Or does one of those trump the other? For instance, say that I bought a drop-in rated at 450+ lumens with a voltage range of 3.6V~18V. Let's also say I purchase an MR16 LED regulator / step-down with the following specs:

*Gino DC 12V 300mA 1 x 1W LED Light Lamp Power Driver for MR16 *



Product Name : LED Driver;Votage : 12V 
Current : 300mA;Material : Electronic Parts 
Size : 2.7 x 1.8 x 1.3cm/ 1.1" x 0.7" x 0.5"(L*W*T);Color : Silver Tone, Black, Red 
Net Weight : 3g 
Package Content : 1 x LED Driver 


Is it ok that the driver is only rated at 12V? If I have 16+V coming in from the battery pack, does the step down AND the drop-in both need to be rated for that? So in essence, do I need to find a step down that is also rated at 3.6V-18V?

Hope my questions are clear...

(Thanks again in advance, this is really helping and I think I'll end up with something almost identical to the original light!)


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## thumpergirl (Apr 29, 2014)

Microa said:


> Don't forget to insulate the driver to the body to prevent short circuit



how do i do that?


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## DIWdiver (Apr 29, 2014)

You should only need one step-down, AKA driver. One rated at 12V AC (like the MR series bulbs) will handle about 17V DC (like your battery).

The brightness of an LED is primarily governed by the current through it. There are better ones and worse ones, but for any given LED the light output is pretty nearly proportional to the current through it. The voltage across an LED is typically 3.0-3.4 volts, and will vary a little with changes in temperature and with drive current. 

The job of the driver is to convert the battery output, which is primarily a fixed voltage at unlimited current, to a fixed current at whatever voltage the LED needs. A driver for a 1W LED will generally put out around 300 mA, or 0.3 amps. The driver in an MR-16 bulb with 1 led and rated at 1W is exactly what you want. It's also exactly like the one I suggested, and likely what's in your light now. The first bulb that Microa suggested has 3 LEDs wired in series. So if each one is 1W, then each will need around 300 mA at 3.3V or so. Since they are wired in series, the voltages add and the current is the same in each LED, so the output of that driver is meant to be 10V-ish, 300 mA. That driver may work perfectly fine with only one LED, keeping the same 300 mA output you want, and only 3V-ish. Or it may not like that, and could overheat or not work properly, or not efficiently. I'd suggest getting one that is known to work with one LED, so if you buy a bulb, buy one like you showed in your last post. A driver from a 3-led bulb may or may not be suitable.

Good modern LEDs put out 100-140 lumens at 1W. This is why you've been looking at 1W. 

Many dropins have drivers that are designed for higher outputs. To acheive this they put more current in the LED. A 200 lm dropin would probably put around 600-700 mA in the LED. A 450 lm one would would push over an amp (1000 mA). Sometimes the drivers can be modified by changing a part, of they can be replaced if you can get the dropin apart, and find a physically similar one to replace it. Or you can purchase the empty dropin and add your own driver. If you use the MR-type driver, it won't go in the dropin, but will be loose in the light body, like your existing light. To insulate it, all you'd have to do is wrap a few turns of electrical tape around it to cover any exposed metal bits.

As far as battery life, it's going to be pretty much inversely proportional to lumens. The exact constant of proportionality is not fixed, and will vary some between different LEDs and drivers, but you're pretty safe to make the following assumptions:

100 lm takes 1W at the LED.
The driver will be at least 80% efficient, so will consume no more than 1.25W per 100 lm.
Your battery pack is about 45 Watt hours

The battery life in hours is the capacity (W-H) divided by the load (W). So in the above example you'd expect about 45/1.25 = 36 hours of life. If you went with a 320 lm dropin, you get lots more light but your load is 3.2W/80% = 4W, so you would only expect 11.25 hours of life.

Of course calculating battery life to 4 significant figures is absurd, but you get the idea.

Your battery life will depend almost entirely on the current setting of the driver. The LED will determine the amount and quality of light you will get from a given driver.


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## Microa (Apr 29, 2014)

Thanks DIWdiver have explained for me in details. After this project, you may become a flashaholic.


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## Mr Floppy (Apr 29, 2014)

thumpergirl said:


> OK, so i can use the drop-in I ordered, open up the pill and remove the driver. Then strip the step-down driver out of any M11 or M16, and solder that in place of the drop-in driver. Then wrap it all up in a p60 host and waterproof the whole thing, and voila?
> 
> Do I need to pay attention to the lumens and voltage from both the MR11/MR16 and the drop-in? Or does one of those trump the other? For instance, say that I bought a drop-in rated at 450+ lumens with a voltage range of 3.6V~18V. Let's also say I purchase an MR16 LED regulator / step-down with the following specs:



If the drop-in has a voltage range of 3.6V~18V then you can just use it. No need to replace it with the driver from the MR lamps, over complicating things.

The easiest way is to get the 503B shell, the P60 dropin you mentioned and that should do. You only need to open up the P60 to solder the wires for power to it but you could even get away with soldering to the underside of the driver board and then assembling the 503B should be waterproof enough. You will need to find IPX8 cable glands though. I did something similar for mountain biking and had IPX6 ones. Bike got dumped into a stream and had some water go through.


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## thumpergirl (Apr 29, 2014)

DIWdiver, excellent post! I think that pretty much answered all of the questions that I had not yet formed into words. It all makes sense now, and I think I understand the very basics of how this all fits together.

Microa, thank you as well! I now understand why my original light looks different than a drop-in, and I know why he did it. 

And yes, I think I may very well become a flashaholic. I can't wait for the parts to come in the mail. I should have at least 2 lights when I'm finished, and they'll both be a little different. I'm sure I will continue to play with this after the race and build more lights. This is stinkin' fun!

I know I'll have more questions once the parts come in and start trying to assemble everything. I'll get good pics and post. I also intend to post the completed solution, in case anyone else out there has the same needs (texas water safari paddlers!!!!!).

Thank you guys so much for your time. I'll be back once the parts are in...


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## thumpergirl (Apr 29, 2014)

but how do I know if it has reverse polarity? I can't tell if it also accepts AC. I can't figure out how you derived that. Seems like it should be obvious, and I'm pretty sure I'm staring right at the answer. ?


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## Microa (Apr 30, 2014)

The 4 diodes near the 2 metal pins form a bridge rectifier which only allow positive go through to positive and negative go through to negative. So no matter which pin is connected to the positive or negative while the other pin is connected to the opposite pole. The circuit works.


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## DIWdiver (Apr 30, 2014)

Get the net! She's hooked!


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## Ken_McE (May 4, 2014)

If you run short of time with your build, this is somewhat similar to your design, and will work with your existing battery pack:

Marine Flood & Spotlight


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## thumpergirl (May 7, 2014)

OK. So I have the dropin. How do I remove the driver from the dropin without destroying everything? I need to remove the driver that's there and replace it with the 1W MR-16 driver. I could just remove the wire leads on there, but then when I solder on the wires to the new driver, there is no hole on the underside to feed the new wires through (see pic). I don't see an obvious way to get rid of the driver.


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## DIWdiver (May 7, 2014)

The driver is the board with the coil spring on it. It's soldered to the brass housing. If you were to remove most of the solder, it should pry out. If you get off all the solder, it should come out easily. The wires you see in the first pic should attach to the back of the driver, and can be unsoldered when you get if off.

Was that white paper between the reflector and the rest of the dropin? If so it's there to make sure the reflector doesn't short the LED when you screw it down. The reflector probably applies pressure to the LED to hold it in place. If the white thermal compound that's still in the pill is not hardened (like RTV or epoxy), then whenever running the light you will need to ensure that you replace the reflector and ensure it applies appropriate pressure to the LED without shorting it.

The second to last picture shows a ring in the inside of the endcap, with two small holes in the ring, one either side of the spring. You can see one of the holes at the far left in the pic. Get a tool like a pair of needle-nose pliers that you can stick into those holes, and the ring will unscrew. The remaining components should come out quite easily after that.


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## thumpergirl (May 8, 2014)

Q: Instead of dismantling the drop in, could I just add the stepdown / buck between the power supply and the driver supplied with the dropin? How much efficiency would I lose doing things that way? I'm going to try that tonight as well. I'll dismantle one of the dropins and wire it up, and i'll leave the other one intact and add the buck and see what happens.


Last night I did a test. I have a dropin that accepts 3.6V to 18V. I wired up the 2pin connector and plugged it into my battery pack. Battery pack had 16.3V when I started. 20 minutes later I came back. The light was hotter than hell - almost too hot to touch. Battery pack had dropped to 15.3V in 20 minutes. So basically, a drop in isn't going to work without some kind of current regulator. The built in driver won't limit the current and it'll just chew through the batteries. I was kind of hoping for a miracle.


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## DIWdiver (May 8, 2014)

What you want is "hookup" wire. Something in the 20-24 gage range. Larger (20 ga) will be harder to solder. Get it at RS, HD, or any old scrapped printer, TV, or something like that.

I'd have said your test with both drivers should have been too bright, too hot, too much drain. But that MR16 driver could have a max output of 4V or so, which could be too little for the dropin to be properly bright. I'd test it directly on the LED before going to a higher current driver.


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## thumpergirl (May 9, 2014)

Picked up the hookup wire at Fry's. Thanks for the info on that. Did some more tests last night.

I haven't done the test with 2 drivers yet. This is time consuming! i did manage to figure out how to desolder the dropin with that mesh wicking stuff, so that worked out well. So, I removed the driver for the dropin and put the MR16 driver in there, hooked up directly to the LED. Hooked it up to the battery pack and VOILA! there was light. It was a miracle.

PRO's: It did not get hot. It did not consume much battery (I'm going to leave it on all day at work to see how long it lasts to confirm this).
CONS's: It did not put enough light though. Not as much as the light I'm replacing. And the throw wasn't what I wanted. I will have blind spots to my left and right.

The light I'm replacing has a nice, soft, maybe yellowish tint. Seems very natural. Also, it's evenly dispersed, or moreso than the lights I'm building. I took a look at things to see where the differences might be. The LED emitter does not have a glass (??) dome over it on the original light. There is nothing covering the emitter. Do you know what that little glass dome does? 

I cannot tell by looking at the original light what the mA rating of the step down is. It looks very similar to the one I have, but I don't know if it's a 300 mA or a 600 mA. I don't know how to find out, either.

What I think I need to do is try a 600aH 3W step down (as opposed to the 300mA 1W I am testing now), and just use an empty p60 smooth reflector (which I have in my posession) and get a CREE XM-L emitter to fit in the empty dropin. I think this will get me close to what I want. I just need to figure out exactly what emitter to get, that will fit in the dropin I have, and figure out what the dome thing is for. Oh, and how to do secure the emitter in the pill? Is there some type of special glue or other adhesive I should use?

Getting close...  thanks again for all your help DIW. This is a fun project (among a few others right now...)


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## thumpergirl (May 9, 2014)

My camera doesn't do a good job of getting details in the photos. Here is a link to the 'dome' thing I'm talking about. What is the purpose of the dome on this emitter plate?


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## thumpergirl (May 9, 2014)

Here is a good photo example of the throw and color, in this forum:


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## DIWdiver (May 9, 2014)

The dome helps get more light out of the LED. Without it, some light would reflect off the inside of the flat surface of the LED and be retuned into the die. All the LEDs you should be looking at will have a dome.

The smooth reflector will create more of a hotspot. A textured or 'orange peel' or OP reflector will give a more diffuse beam.

Also, a bigger die will give a larger hotspot, so the XML would help a bit with that. Just not a lot.

If you want to avoid the harsh bluish light, you want an LED with a color temp below 5000K or so. 5000 is kind of neutral, 4000K is getting warm and a 'warm' white is 3000K or less. IIRC the XML is available in 2700-8000K or so.


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## jabe1 (May 10, 2014)

I wouldn't worry about the LED having a dome or not. Try to go with an XM-L, you'll get a lot of lumens for your power level, and a good sized hotspot.
The dome on the LED acts as a primary lens to help focus the beam. If you want more flood and less throw, keep the dome, and use an orange peel, or stipples reflector.

I would be interested in seeing what the old LED was.


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## thumpergirl (May 11, 2014)

jabe1 said:


> I wouldn't worry about the LED having a dome or not. Try to go with an XM-L, you'll get a lot of lumens for your power level, and a good sized hotspot.



How will the XM-L[2] compare to the XP-G[2]? Both state a 'larger' die size in the flashlight wiki, http://flashlightwiki.com/ but I'm not sure which is larger and will give me more 'flood'. Probably the best way to find out is to order both and try them out. I've got an XP-G2 R5 on the way

Regarding the XP-G2 R5, i think the R5 bin means it will be a 'cool white', although i want more of a nuetral. But the cool always puts out more lumens. Is that a correct statement?

I've also discovered that it's not all about the lumens. The color, flood, throw all add up. I think the best way to figure it out is to put together several lights and see which one works / looks the best. So, that's my plan. You should see my kitchen table. It looks like a science experiment. I really don't have time for this, but it's so fun. I digress...

Before I really understood just how much difference the emitter actually makes, I bought a couple of cheapie parts online and assembled them. I wasn't even sure what I was dealing with. Q5. It sounded good. I pulled out the drivers in both lights and replaced them with the MR16 bucks. Both lights worked. Both lights looked almost exactly the same, except one had a blueish tint (probably higher lumen output but I don't have a way of measuring it) and the other a nicer more natural tint (preferable for me). Upon farther inspection, I believe they are both old XR-E emitters (you can tell by the distinctive metal ring around the emitters), problably both outputting in the vicinity of 110 lumens. It looks like the XM-L2 or XP-G2 will put out about 150 lumens at 350mA. That should make a difference on the river. Also, I'm guessing that both of those have a larger die than the XR-E. At least the XM-L does according to both of you guys.

What bin would correspond to 'neutral' (~5000K) for the XM-L2 and xp-G2?




> I would be interested in seeing what the old LED was.


 Upon closer look, it looks like an XM-L, but I'm certainly no expert in identifying these. I can't visually match it to any other emitter on the flashlight wiki.


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## thumpergirl (May 11, 2014)

Regarding reflectors and flood. I've heard some people say that it's the die. I've heard others say it's not the die at all, that it's the reflector. My guess is that they are both involved, starting with the die. 

That said, are all reflectors created equal? I know there is smooth, textured, and orange peel. (Maybe textured and orange peel are the same, not entirely sure but I thought there was something inbetween smooth and orange peel EDIT: I see you mention stipple above, that must be what I was thinking of...). It seems like the actual shape of the reflector would make a difference in the throw. I haven't seen a lot of different intel out there on reflectors, and there don't seem to be a host of choices on websites when purchasing.

In addition to a decent flood, I'm looking for a wider viewing angle. I will need to know what's to my left and and my right on the river at night, in order to avoid obstacles as they arise...

The reflector in the picture above is actually a smooth reflector, but the light had decent flood. I know it doesn't look smooth but it got salt water in it and is corroded. It is smooth to the touch.

If there's a particular reflector that anyone recommends for a good combination of flood and throw, I'd love to hear about it. And if there are options regarding depth, and for lack of a better work, 'scoop', I'd like to hear about that too.


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## thumpergirl (May 11, 2014)

DIWdiver said:


> The dome helps get more light out of the LED. Without it, some light would reflect off the inside of the flat surface of the LED and be retuned into the die. All the LEDs you should be looking at will have a dome.
> 
> The smooth reflector will create more of a hotspot. A textured or 'orange peel' or OP reflector will give a more diffuse beam.
> 
> ...



Great info, thanks DIW. I've ordered a 
Cree XM-L2 T5-5D 260LM 4000-4300K LED Emitter 
to see what the output looks like on that.

The clock is ticking... I should be out training today but I almost split my hull in two on a training run yesterday, so today is gadget and repair day.

Thanks again for all the help on here.


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## DIWdiver (May 11, 2014)

Bummer about the hull! Sounds like you can fix it though. Good luck.

If you want the greatest possible throw, you would really want all your light to come from a single point. A spherical lens or a parabolic reflector could focus this into a perfectly collimated beam (all light rays travelling perfectly parallel to each other), which would have theoretically infinite throw. Add a second point, and no matter how close to the first, no optic could focus both points into a single perfectly collimated beam.

When you have an LED, it has a nearly infinite number of point sources spread over an area. So you'll never be able to get a perfectly collimated beam. But the smaller the LED, the better beam is possible. Also, the bigger the optic, the better is possible. That's why people going for throw talk about die size so much.

But if you aren't attempting the tightest possible beam (read: greatest throw), then the die size becomes unimportant pretty quickly.

Even discounting the surface finish, all reflectors are not created equal. They are all parabolic, but they differ in scale and aspect ratio (these are my terms, so don't expect to find them in other discussions). The scale is related to how pointy the theoretical tip of the parabola is, which also affects the 'slope' of the sides. The aspect ratio is the ratio of the depth to the diameter. Technically it's the depth from the rim to the focal point, which can be slightly inside or slightly outside the actual part, and it's the inside diameter at the front edge. Practically, it's the depth from the rim to the LED surface, which can be slightly in front of or behind the focal point.

Obviously, with a wide, shallow reflector (low aspect ratio) much of the light will escape without ever hitting the reflector. This is the 'spill'. With a deep, narrow reflector (high aspect ratio), much more of the light will be gathered by the reflector and focused into the 'hotspot'.

Since you are looking at P6 reflectors, the diameter and depth are pretty nearly fixed. There's not much a manufacturer can do with either the scale or the aspect ratio before the reflector becomes impossible to fit in a P6. But there will be small variations. Also, the location of the LED w/r/t the focal point will have an impact on what the beam looks like. In most dropins, this is something you don't have easy control over. Some you can unscrew a little, but if you unscrew them much, either they come apart or they won't fit in the light.

So for the most part, reflectors you will be looking at are all pretty similar, except for degree of texture. BTW - OP, orange peel, stipple, texture, are all the same thing. Smooth or SMO is the opposite.


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## jabe1 (May 11, 2014)

You should like the results you'll get with the XM-L2 neutral in an OP reflector. The spill will be brighter, allowing you to see more to the sides.


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## Microa (May 12, 2014)

Hi thumpergirl, if you have time, you should have a look of this video which shows how to modify a flash light. http://budgetlightforum.com/node/29612#node-29612


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## thumpergirl (May 15, 2014)

Great videos, Microa. Thanks for the heads up. Watched them all and they were very informative and helpful.

Edited: I asked a question here, but it was already answered by DIW in an earlier post in this thread. Some of this stuff I have read several times for it to sink in!!!!


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## DIWdiver (May 15, 2014)

A 1x3W driver would have an output of around 1000 mA. That's what makes it 3W: 1000 mA * 3V = 3000 mW = 3W.

A 3x1W driver would have an output of around 300 mA, and still 3W total output because the voltage of 3 LEDs is more like 9-10V: 300 mA * 10V = 3000 mW = 3W.

Keep in mind that a "3W" driver is only an approximation. It's more like a "3W class driver". We talk about 1W, 3W, 5W, 10W drivers like car people talk about compact, mid-sized, and full-sized cars. In both cases, the devil is in the details.

So the 1000 mA output would give you roughly 3 times the light output. To your eye, this will look like a lot less than 3 times the brightness. It will also be three times the load on the battery, which will drain it 3 times as fast.


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## thumpergirl (May 19, 2014)

> Your battery pack is about 45 Watt hours



Can you tell me how you calculated that?


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## thumpergirl (May 19, 2014)

*Update:*

Got plenty of parts in. Went overboard on parts. Have parts coming in probably for the next month or so, and will have probably 10 flashlights built. I wanted to try all sorts of different configurations. This might turn out to be another 'problem' (ahem, obsession) for me.

Ordered a Solarforce L2 host but was shipped a Uniqefire L2. Quality seems to be about the same so no big deal there, and would take too much time to remedy the situation. Picked up an XP-G2 emitter on a 10mm PCB (needed a 16mm but they didn't have it) and an empty drop-in. Used Arctic Silver thermal adhesive to adhere the PCB to the pill. I'm not the best at soldering the lead wires to the PCB yet, but hopefully that will improve with time. Maybe a different tip on the iron will help with that.

So, hooked all that up with the MR16 300mA driver, with the cable gland and 2 pin connector. Used some E6000 to waterproof all the joints. Put it on a fresh pack of 10 AA alkaline batteries for a test (lithiums are just too expensive to waste on a 'test'). So far the light has been running for 20 hours, nonstop, with no heat issues and seems to be outputting the same amount of light. It will be interesting to see how long it will run before dying.

I am assuming that the lumen output will not change as the battery pack drains, because the MR16 driver will continue to deliver 300mA until it can no longer do that. I'm expecting the light to shut off abruptly, rather than beginning to dim before it goes out. Can anyone shed some light on that? (pun intended)

I have also hooked up an XML T6 emitter into a Solarforce L2 host. Can't remember the color bin but it seems much warmer the the color bin on the XP-G2. The XML T6 was a drop-in that I disassembled and removed the driver, then added the MR16. This was a little more expensive, but nice because the lead wires were already on the PCB, which was the right size and already epoxied to the pill. It also comes with the correct sized thermal gasket. It's quicker and less hassle to put together, but probably costs about an extra $10 based on where I got the parts.

Next I will try with a 600mA driver and see what kind of output I can get with that, and how long it will last. I would guess based on what DIW has posted on this thread, that the battery life would be about half, and the lumens would about double. I might be able to pull that off and bring 2 battery packs with me to the race. More testing...

I should be getting around 140 lumens from the XML but I don't have a way to test/confirm that yet. I've got some XM-L2's on the way, so it will be interesting to see the differences there, provided I can find an affordable way to accurately test lumen output. Hint: Smartphone apps don't work well.


Waiting for thermal gaskets to be shipped from overseas. Is there something around the house that would suffice in the interim? Need to cover the lead wires from the emitter board so they don't make contact with the reflector. Wondering if I can use a hole punch to make some out of electrical tape.

Pics coming, and I'll report on the final run time when the light finally goes out.


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## thumpergirl (May 19, 2014)

thumpergirl said:


> Can you tell me how you calculated that?




Nevermind. DIW, it turns out you've answered a lot of my questions before I even knew they were questions I'd have.  From another thread where you stated:

"But an Energizer Ultimate Lithium cell is around 3000 mAH, at 1.5V, so that's a total of 4.5 W-H (that's Watt-Hours). Ten of them would give you 45 W-H."


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## DIWdiver (May 19, 2014)

Well, it (probably) won't wink out like turning off the switch, but it will go from full on to nearly nothing pretty quickly. Or it might start flickering.

The XM-L2 will be a bit brighter than the XM-L, but it may not be detectable by eye unless you have them running side by side.

Measuring lumen output requires an integrating sphere. You can get a lux meter on the internet pretty cheap, but that's not the same thing. Lumens are the total light output, lux (or candlepower) is brightness at a single point. Change the focus and you change the brightness, but not the lumens (at least not much).


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## thumpergirl (May 20, 2014)

Replaced the driver last night in one of the lights. Much more light. The host gets a little hot now, but not too bad. Not sure I need that much light, but I'll take them both out on the river this weekend on a night paddle and see how much difference it makes in a 'real case' environment, versus a bright spot on a white wall.

On one of my first tests a couple of weeks ago, I got a drop-in with a voltage rating that allowed for my battery pack to run the light without any driver modification. The host got so hot after a while I could no longer pick it up. 

The XP-G2 neutral is still running on the original 10 alkaline AA battery pack. I'm now at 32 hours and it's still usable. (easy to say when you're not avoiding river obstacles at 5mph)

Regarding measuring lumen output, there was a great article I read a week or so ago on the budget light forum about making your own integrating sphere. When the race is over and I have more time, I may try to make that a project so I can really tell the end result of all of these different components.


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