First laser build, 405nm

Hello, LPF, I joined here so I could get some help with a first build. I recently had an XBox 360 HD DVD drive dumped on me and decided instead of trashing it, I'd make a laser since I once saw a video of a laser from it. So I researched a little and found out what parts I needed. I plan on running this thing off a 9-volt battery with a custom driver made from an LM317 and resistor. I'm ordering the following parts online:

HighTechDealZ - Aixiz Laser Module - Blank

HighTechDealZ - Aixiz 405nm Coated Glass Lens

HighTechDealZ - 9V Battery Snap Connector

As well as a 405nm sticker from the same place. I'll be getting the stuff I need for the driver from my local Radio Shack. My question was, what current do you guys recommend? I want it to be reasonably powerful and I am putting it in an old heat sink from a dead computer with lots of thermal glue. The driver will also have a small southbridge heatsink. I was trying to figure out what current wold be good for battery life/performance. I also could wire two batteries in parallel and boost life, couldn't I?

I should also mention that I already extracted the laser diode with no problems, and hit the rest of the drive with a sledgehammer. I'm saving the casing and stuffing a tiny computer inside of it, but that's another story.

Thanks in advance for any help, sorry if I'm asking stupid questions.

~115ma should be good

I wouldn't run it off a 9v battery, I'd use 2 10440's or something similar. You would be forever changing the battery otherwise. 115mA would be good for a long life but you would only output around 90mA. I've got my comftably running at around 180mA and have had 4 min run times w/out it getting warm but the lifespan would probably be decreased a little, it all depends on how far you want to push the little thing

Welcome to LPF and don't forget to read the stickies

I have never had to change the 9V on 300ma 660nm but I might just be lucky

PHR's need more juice if I recall

Kookapeli said:

PHR's need more juice if I recall

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They do have a higher forward voltage which could limit the battery but as far as current I am running ~3x the phr at 115ma vs ~310ma. Either way a 9v is fine for a quick build until he gets a proper host that can hold Li-ion batteries.

midias said:

I have never had to change the 9V on 300ma 660nm but I might just be lucky

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...im sure you dont have a magic battery. 9V are not good batteries for long term use for lasers. I use them for testing reds as well because the driver I use requires higher voltages...but this build wont be using that driver.


You need to select your batteries based on the needs of your driver. I do agree though that if you plan on putting this in a host go with something other than a 9V

OOh, one more thing, you will need to build a test load to make sure you don't overpower your driver or mis-calculate anything, better to be safe than blow your phr and remember to short the cap on the driver before you solder the diode on to it

Thanks for the tips. I probably don't have to worry about heat since I am sticking it in a CPU heatsink and pulling a lot of air trough it with a pretty powerful fan. Would 200ma work well? Reason I want to put it on a 9volt is because I don't want to have to buy rechargable batteries and a charger. However, a local electronics store sells some pretty powerful rechargables. I'll see if I can find some suitable candidates after I get this thing working. Also, what exactly is a test load? I understand it makes it so your driver circuit doesn't kaboom without a diode, but what is it exactly?

Basically it acts as a diode so you can adjust your driver to the desired output you want. 200mA may be a little high. I'd stick with around 150mA to be on the safe side. Also it's better to use lithiums as you will get longer battery life.

MacTrekkie said:

Would 200ma work well?

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No. 110mA or so is the best compromise between lifetime and power.

MacTrekkie said:

CPU heatsink and pulling a lot of air trough it with a pretty powerful fan.

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A CPU heatsink is plenty large enough. You can leave the fan off.