First Red Build

[kkEdlund]

I've been poking around this forum for a week or two, and I think I'm going to try to throw together a little red laser. I'm not entirely sure what I'm doing, so any input is welcome, but this is the plan:

The diode will be this one:
laser surplus parts.com/shop/13-16x-high-power-red-laser-diode.html (remove spaces, the forum doesn't like that link for some reason)
Its cheap, and since I have no anti-static equipment, laser experience, or extreme soldering skills, I'd prefer to start with a diode I can kill without bankrupting myself.

I'm planning to use this housing from O-Like. I assume that one would work as well as one of the Aixiz housings, but I really don't know. I like it because it is cheap, and this laser is on a big-time budget, but if I need a nicer one I'm open to recommendations.

The driver will be another O-Like product. I assume this driver is as good as the next, but again, I'm new to this stuff. If this driver is too cheap for its own good, I'd be willing to try a different one or even attempt to build my own

As for a power source, once the diode and driver are fitted in the host, I plan to look at what kind of space I have left and get an appropriately sized NiMH battery pack of probably 4.8V.

And for a host, I'd like to use this. Now, I don't know how to try and heat sink the diode in that host, so I guess it will be limited to a short duty cycle, heat sinked by the housing itself. I'd prefer to use a proper heat sink, however, and if anyone has experience using heat sinks in confined spaces, I'd love to hear about it.


I have a few more questions:
The driver says its input voltage is 4-6 volts, and the output is 2.5-2.8V. I assume this output conditional upon the input, so it will decrease as the batteries die. The diode data sheet
laser surplus parts.com/shop/attachment.php?id_attachment=1 (same deal, copy/paste and delete spaces)
claims the diode's maximum operational voltage to be 3.2V, and the 'Typ.' (typical?) voltage to be 2.7V. So, if the driver is outputting 2.5V, will the diode still operate (no minimum voltage is specified)? Also, the 'Typ.' current of the diode is 150ma, and the maximum is 200ma, so I plan to drive it at about 160-180ma. So, when properly set, the driver will have a maximum output of .18A, 2.8V (A*V=0.504W) or 504mw. With the diode's peak output at 240mw ( I assume that would be driven at max current, 200ma. I'll be driving it a little lower than that), I will still have around 300mw of energy converted to heat. The diode's absolute maximum operational temperature is 75 degrees C, so I'd like it kept well below that. Does anyone know the formula to determine how much heat will be produced by that 300+ mw that are not converted into optical output, or know if the heat would build up too quickly for the laser to be useful? Also, I have no idea what is going on in that driver, would it need to be heat sinked as well at power levels this low? And if not, would the heat from the driver/diode be detrimental to the plastic host this is all going into?

 

[kruser495]

use an axiz. its cheaper. your link for your diode doesn't work. im guessing it a lpc-815? i would also go with a 10440 lithium rechargeable. there smaller!

 

[kkEdlund]

use an axiz. its cheaper. your link for your diode doesn't work. im guessing it a lpc-815? i would also go with a 10440 lithium rechargeable. there smaller!

The AixiZ housing with the glass lens is a little more expensive, is it not? At least, to buy if from AixiZ website it is. If you have a link, that would be nice. As for the battery, I don't have a working lipo charger. Would it be worth it to invest in a new charger to go with the battery?

 

[kruser495]

The AixiZ housing with the glass lens is a little more expensive, is it not? At least, to buy if from AixiZ website it is. If you have a link, that would be nice. As for the battery, I don't have a working lipo charger. Would it be worth it to invest in a new charger to go with the battery?

hightechdealz.com is a very good website. the lowest prices you will find. its 3 bucks for the axis.

on ebay you can find a charger with 2 batts of 10440 for 6 bucks.

 

[kkEdlund]

hightechdealz.com is a very good website. the lowest prices you will find. its 3 bucks for the axis.

on ebay you can find a charger with 2 batts of 10440 for 6 bucks.

Thanks for the tips. However, the driver I'm looking at specifies an input voltage of between 4 and 6 volts. A single cell LiPo will deliver 3.7V, but 2 will give me 7.4V. So either way, it does not fall within the driver's specifications. Any idea where I could find a low-priced driver that can output 2.7-3.2V at 180 ma, preferably off a 3.7V input (ie. one 10440)?

Thanks,

Kristoffer

 

[kruser495]

build one your self, its very easy and cheap.

read thisLaser driver - It can be done

 

[LtKernelPanic]

Here's a couple suggestions for doing your first build:

Host:

I'd stick with a host kit that has the host and matching heatsink. You can get nice kits for $30-40 in the BST or LPS forums here.


Driver:

The flexdrive is the king of drivers. A single 18650 should give you plenty of runtime. If you want a cheaper prebuilt driver you can use the rkcstr but you'll need 2 batteries which narrows your host selection a bit.

If you can build a simple circuit you can build a LM317 or LM1117 based linear driver. You can see examples of them in my 405nm hotlights build and my 635nm pen build. They're basically the same driver krusr495 linked to. I decided not to use any filter caps or diodes to save room in my hosts but note while that the drivers I built work fine they will not protect the laser diode against any voltage spikes or if you put the battery in backward like the full driver he shows on that page. Also make sure your resistor(s) is rated for the correct wattage. You the calculator here to find out the values needed for a given mA output.

http://www.reuk.co.uk/LM317-Current-Calculator.htm

Whatever driver you use you'll also need to build a test load to use while setting your driver. For lower powered builds like this one four 1N4001 in series with a 1w 1 ohm resistor will be fine. There's a basic one on rog8811's site with instructions for use.


Good luck!


Edit: Helps if I add th elink to the calculator I was referring to.

 

[Lotus_Darkrose]

I am a new fan of the flexdrive Just finished my first laser fully made by me (with the exception of the LOC diode being pressed in) Friday. Highly recommend if you can afford it.

I used to have a phr laser with a rkcstr driver and that worked just fine. But if you are looking to build your own, a flexdrive really helps unlimit you from host size restrictions. Just like LtKernelPanic said.

 

[LtKernelPanic]

Flex drives make a first build a lot easier although I decided to go the stubborn route and build a LM317 driver into a pen host as my first build.

Linear drives work great if you have the room and don't want to spend the money for a flex drive which is exactly why I built my own for my PHR build (which has turned into one of my favorite lasers). One last thing about DIY linear drivers if used to power high powered builds they give off a ton of heat so you'll have to heatsink them as well.

 

[bennett326]

your right that housing has a glass lens were the aixiz comes with an acrylic lens i would go with the glass lens also that module is bigger so you wont have to worry quite as much about the heat sinking compared to the aixiz. as far as the driver i would also build your own...(to make it cheaper).. if you don't mind spending the money you could buy a groove v2. with both drivers you could use two 10440 i recomend buying protected cells but thats just me

good luck on your first build

 

[LtKernelPanic]

If you're using a flashlight host that uses a battery holder such as the guidesman or hotlights hosts in my build threads, be careful with protected cells. They'll likely not fit. I normally prefer protected cells as well (it took me almost a week to revive a cell that I managed to run down to .8v) but in some hosts they just won't fit.

 

[kkEdlund]

Thanks for all the feedback.

If you're using a flashlight host that uses a battery holder such as the guidesman or hotlights hosts in my build threads, be careful with protected cells. They'll likely not fit. I normally prefer protected cells as well (it took me almost a week to revive a cell that I managed to run down to .8v) but in some hosts they just won't fit.

I'm using a mini nerf gun as a host (see my first post) so I should be able to fit the battery in just fine

...also that module is bigger so you wont have to worry quite as much about the heat sinking compared to the aixiz.

Does that mean I could get away with no additional heatsink at 200 mA, if I keep it to a short duty cycle, or is no heatsink ALWAYS a dumb idea?

Flex drives make a first build a lot easier although I decided to go the stubborn route and build a LM317 driver into a pen host as my first build. Linear drives work great if you have the room and don't want to spend the money for a flex drive which is exactly why I built my own for my PHR build (which has turned into one of my favorite lasers). One last thing about DIY linear drivers if used to power high powered builds they give off a ton of heat so you'll have to heatsink them as well.

Space is at a premium, so I guess I may have to go with a flexdrive. What I need is a driver I can fit into a fairly confined space and be able to get ~2.7V output of a single LiPo (3.7V). I was under the impression that only some kind of boost driver could do this, as the voltage drop for even the best drivers was ~1.25V. Am I just confused here? What is the most space and cost-effective way to provide 2.7V to the diode from a single LiPo?

Thanks again,

Kristoffer

EDIT: I guess I need to rethink the driver I will be using, as that one from O-Like can't run on a single 10440. Can anyone recommend a driver that can output 180ma at 2.7V off a single 10440 battery? I guess a FlexDrive could, but I'd like something a little cheaper.