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Modular PHR Build

rev0

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Hello all, I just thought I'd post info about my project since I thought it was a bit unique and might be useful to others starting a project.

Type: PHR-803T 405nm
Current: ~90mA
Output Power: 107mW (Measured with IR thermometer)
Style: Flashlight Host, 14500 Battery
Total Project Cost: ~$40
~$10-15 Flashlight host (Ebay, ages ago)
~$3 Various parts (Digikey/Mouser, stuff I had laying around)
$2.15 (x3) CC LED boost driver (DealExtreme)
$2.92 Sure module with included acrylic lens, back cut out (HighTechDealz)
$2.36 14500 Battery (DealExtreme)
$17 PHR Diode (Ebay, yeah I know it's a bit overpriced)

End result:


Step 1: Research
So I have been planning to do a couple builds, one with the PHR and another with an SLD1236VL red laser, and had ordered some surface mount LM317's. However, there was the problem of battery voltage. The LM317 has a voltage drop of about 2V or so, meaning I'd need a battery voltage of at least 7V for the Bluray. So seeing as my only flashlight hosts were 3-AAA, that wasn't really feasible. I also knew how to make a constant current driver with a transistor, current sense resistor, and MOSFET, via this Instructable, and it turns out this type of driver has a much lower voltage drop, just the voltage drop of your current sense resistor in theory. Then I discovered that I had a few of these LED drivers laying around: DealExtreme: $6.46 AA and 14500 Circuit Board for 3.7V LED Emitters 3-Pack (1.5V~4.2V Input)
Turns out these were perfect, they are constant current boost drivers, and open circuit, they produce about 6.6V, just a little more than I'd need for the MOSFET drivers.

Step 2: Putting together the host
So now my plan was to put that boost driver in a flashlight host, and connect it to a female header that I could plug in a laser/Aixiz module with a driver into. I drilled a 1/2" hole into the lens cover and reflector to fit the Aixiz, and drilled another hole in the aluminum cylinder that previously held the LED. After lots of hot gluing and a little soldering, the end result is this:





The host was designed for one of those 3-AAA cartridges, but after an hour or so of use, they burned out, so I stuffed some cardboard in there and put a longer spring on the cap, and now it's a AA-powered host! Yay, boost converters!
Update: Switched to a 14500 Li-Ion battery and replaced cardboard with 1/2" PVC. Boosted the power by about 25%


Step 3: PCB/Driver
This part was easy, but very tedious. I just reused the design for my IR burner's driver.
I uploaded the schematic/board Eagle files below, if you want it.

Here's the schematic:


Here's the board:


The two jumpers J1 and J2 are just for a jumper wire, I couldn't get everything to connect on just a one-sided PCB.
The diode is for reverse polarity protection, it is a 3A Schottky with a voltage drop of only 0.3V at 100mA, so it doesn't hinder performance at all.
The two capacitors are for ESD protection, though they probably wouldn't do much of anything. I tried to come up with a design using some TVS diodes I ordered, but it just wasn't practical, at least not being driven at a lower voltage like this.
The 1 Ohm resistor was initially there for measuring the current, but it's not really necessary since it's a linear driver, I could just measure current through the whole circuit externally. The 5.6 Ohm resistor is the feedback resistor, calculated via the following: Iout = 0.5/R.
The MOSFET is the series-pass element, whose resistance is raised or lowered to keep the current the same.
The BC817 transistor is a generic NPN transistor that controls the voltage to the MOSFET gate by monitoring the voltage/current at the feedback resistor (not really sure how this part of the circuit works, actually).
Lastly, the 100k Ohm resistor is just to "pull up" the MOSFET's gate to the input voltage. If this isn't present the MOSFET will just stay off, or at whatever lowest voltage the transistor provides.

Here's the pre-etched boards, after fixing up some broken traces with sharpie:


Boards etched, stripped, and drilled:


Parts dry-fit:


Finished module (the driver was a little too big to fit in the Sure housing):



Success!:


Obligatory beam shot:


Obligatory match lighting:


Cool fluorescence in a wine glass:


Since the Sure module back didn't fit my driver, I ended up just hot gluing the heatshrinked module to the lens cover, but it is pretty easy to remove and add in a new laser if I decide to.
 

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kiyoukan

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Very nice build great quality and amazing documentation, You have a very nice future here.
 

Eudaimonium

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Dude, that's about the coolest thing I've seen in a while.
Boosting circuit, and then you have interchangeable heads each with it's own current regulator.

Awsome work!

What are the capabilities for boosting circuit, if it can provide around 400mA you will also be able to squieze in some red build in there,
But in any case, GGW diodes operate at 200mA so you can modulary upgrade your laser.

Very cool!

Also, if you want to use thinner battery than the host was intended for, you can use some PCB tubing to get the desired "sleeve" ,instead of cardboard, it will look much better.
Also, it higher power applications, hot glue tends to melt so you might want to epoxy your next experiment, my LM1117 meltet host glue that was holding it in place at 470mA once, so I had to think of another way.

What is the current draw from the battery, with this PHR build?
 

rev0

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What are the capabilities for boosting circuit, if it can provide around 400mA you will also be able to squieze in some red build in there,
But in any case, GGW diodes operate at 200mA so you can modulary upgrade your laser.
I forgot to measure the boost circuit, but I found this info on DealExtreme: "The spec that came with the board claims it has two types of outputs: when using an AA battery (voltage <= 1.5V), it steps up the voltage to 3.7V with 350mA current. When using a 14500 battery, it regulates output at 850mA."
I'll probably swap to a 14500 if I do any higher power modules.

Also, if you want to use thinner battery than the host was intended for, you can use some PCB tubing to get the desired "sleeve" ,instead of cardboard, it will look much better.
Haha, yeah the cardboard was a quick fix I did this evening, I'll try to pick up some PVC sometime, hopefully I can find the right size.

Also, it higher power applications, hot glue tends to melt so you might want to epoxy your next experiment, my LM1117 meltet host glue that was holding it in place at 470mA once, so I had to think of another way.
Yeah, I was thinking about that, this module doesn't get too hot in use, but I think maybe I can superglue down a rubber o-ring on the inside of that lens cap to hold modules in place in the future.

What is the current draw from the battery, with this PHR build?
Current draw is 250mA, so I should get a good 8 hours out of a 2000mAH NiMH, if the quoted specs are correct.
 

Eudaimonium

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I forgot to measure the boost circuit, but I found this info on DealExtreme: "The spec that came with the board claims it has two types of outputs: when using an AA battery (voltage <= 1.5V), it steps up the voltage to 3.7V with 350mA current. When using a 14500 battery, it regulates output at 850mA."
I'll probably swap to a 14500 if I do any higher power modules.



Haha, yeah the cardboard was a quick fix I did this evening, I'll try to pick up some PVC sometime, hopefully I can find the right size.



Yeah, I was thinking about that, this module doesn't get too hot in use, but I think maybe I can superglue down a rubber o-ring on the inside of that lens cap to hold modules in place in the future.



Current draw is 250mA, so I should get a good 8 hours out of a 2000mAH NiMH, if the quoted specs are correct.
Hmm, NiMHs tend to drop under 1.2V real soon, wich will be even higher current draw, or even shutting off the driver, I'd go with 14500, Lithium Ion batteries are the best there is, I use then in almost all of my builds.

However, it seems that you are doing great with materials that you have, and I applaud, you are very wayfindy :D

I can't wait to see your 445nm builds...
 

Morgan

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Yeah, I was thinking about that, this module doesn't get too hot in use, but I think maybe I can superglue down a rubber o-ring on the inside of that lens cap to hold modules in place in the future.
Great innovation. Nice work!

Just a note on superglue... The vapour can fog lens assemblies so, if you can't find an alternative, (highly recommended!), then be sure to remove lenses from the area.

Good luck.

M
:)
 

Eudaimonium

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Great innovation. Nice work!

Just a note on superglue... The vapour can fog lens assemblies so, if you can't find an alternative, (highly recommended!), then be sure to remove lenses from the area.

Good luck.

M
:)
Yes, exactly
Cyanoacrylate super glue will make a horrible mess out of any optics, so make sure that you use epoxy in presence of sensitive optics sucs as lenses, or in green lasers, set of crystals.
 

Kevlar

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1/2" PVC fits perfectly for hosts that are designed to hold the 3XAAA battery cartridges! I used this for my MXDL 3405 build, now I use 2CRs. The only difference is the CR2 has a diameter of 15mm and the AA is 14mm so there would be a little rattle but I'm sure you could remedy that. Nice build BTW!!
 

rev0

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Yes, exactly
Cyanoacrylate super glue will make a horrible mess out of any optics, so make sure that you use epoxy in presence of sensitive optics sucs as lenses, or in green lasers, set of crystals.
I was only going to do this with the laser module removed, superglue doesn't cause problems once dry, right? I could do epoxy afterwards, superglue is just convenient to hold it in place first.
 

Eudaimonium

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I was only going to do this with the laser module removed, superglue doesn't cause problems once dry, right? I could do epoxy afterwards, superglue is just convenient to hold it in place first.
Yes, once dry it will not do any harm.
 

rev0

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Hmm, NiMHs tend to drop under 1.2V real soon, wich will be even higher current draw, or even shutting off the driver, I'd go with 14500, Lithium Ion batteries are the best there is, I use then in almost all of my builds.

However, it seems that you are doing great with materials that you have, and I applaud, you are very wayfindy :D

I can't wait to see your 445nm builds...
Took your advice and went with a 14500, boosted the power up to about 107mW! (Again not sure how accurate my readings really are, I'm using the IR thermometer method) I guess the boost driver is either able to provide more current or produces a higher voltage, not quite sure what's going on without getting in there and making measurements. I also replaced that cardboard with 1/2" PVC.

Rather than take apart my lovely PHR I opted to make a separate 650nm build, in an MXDL host. Two lasers are more fun that one interchangable one ;)

Next up will be my SF-AW's, as soon as the others in AMK's group buy pay up. I'm not so sure I want to dive into the 445nm world just yet. (My wallet thanks me for the delay as well)
 

HaloBlu

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Love the interchangeable heads. Great documentation.
Hope to see more of your builds. :D
 

nosebleedXD

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hey did you just drill a hole through the plastic lens of the flashlight and shove your axiz module into it?

i wanna try that as i dun have one of those heatsinks
 

rev0

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hey did you just drill a hole through the plastic lens of the flashlight and shove your axiz module into it?

i wanna try that as i dun have one of those heatsinks
Yup, simple as that. A 1/2" drill bit will work well, it's just a little loose for an Aixiz module.
 

Eudaimonium

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oh cool i plan on buying this host
DealExtreme: $10.90 C6 DIY Cree LED Flashlight Full Casing/Shell with Driver Pill (2*CR123A/1*18650)

will a sure module + rckstr driver fit into the host

and will two cr123s be able to power a phr?
My fav host , you can check out the "100mW green" laser in my signature to get a picture of inner construction which calls out for a laser in it! :D

Yes , you can use 2x CR123 (they are called 16340 if we are talking li-ion secondaries), and you can use RKCSTR driver to power a bluray diode.

For more juice, higher power applications and longer battery life, I would like to advise you to get 18350 instead of 16340, they are a bit larger, bigger capacity and current delivery capabilities. However they still fit inside 18650 barrel so no worries there.
I'm amazed that DX does not stock some, you can find them on DinoDirect.com.
 




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