Blue-Violet 405nm laser diode

[Bakawun]

I am new to the world of lasers but am diving in head first. I am shredding a Maglite flashlight and swapping in a 405nm laser diode for the bulb. I've looked into how to connect it and that doesn't bother me. However in discussing with various people (Kip Kay sent me here), I've been told I'd need a driver in order not to blow the diode fairly early in its life. If so what kind of diode/how should I set it up? I intend to use the laser as a star pointer as well as a burning laser, but I do not think I'd have any reason for using it at very high outputs. That said, is there a way to avoid a driver and still maintain laser life? Any tips would be greatly appreciated! Also, where can I get a good price on a 405nm blue-violet laser? I found some on eBay with decent pricing, but this seems to be where the experts are, and I'd love some advice. Additionally, if I do need a driver, and I still want to fit it into the housing of a Maglite flashlight, it would need to be pretty small; how small can they get and where can I get/how can I make such a tiny driver?

Many many thanks, Philip

ZAAAAAAAAAAP!!!!

 

[Eku]

You NEED a driver.

Here's a guide.

http://www.laserpointerforums.com/forums/YaBB.pl?num=1236932268

 

[chipdouglas]

Yes you need a driver. a rckstr or a flex drive or the diy ddl driver. But if you are looking for a star pointer, a low powered blu-ray isn't going to work. It would be best to buy a green. They are pretty cheap for descent power. I have 50mw from www.ledshoppe.com it works great and has an amazing beam. ;D

 

[robjdixon]

2 x AAA batteries aren't enough to run a blu-ray, so you need some sort of driver. Also, there is the dead diode problem if you don't use a driver

 

[Bakawun]

Okay so thanks for all the great input guys; it's been really helpful (especially the tutorial). Now I need to know where I can get a good diode and driver. I'm looking to keep costs down, but I want the most I can get for my money. I found some on ebay for roughly 40-50$ including a driver, but I'm not sure if the driver is any good or that's a good price for such a laser. What's everyone's take?

Thanks again, Philip

ZAAAAAAAAAAP!!!!

 

[charliefreck]

the ebay kits are reasonable. they will work fine. you might be able to go cheaper if you source the parts individually, but then you have to pay multiple shipping charges etc. the drivers are also fairly large, and designed to run on 9 volts. the flexdrive (hacylon.case.edu/ebay/laser_diode/Micro_FlexDrive.php) works differently. it is very small, and can run off lower voltage.
a flashlight conversion is not as simple as you might imagine. there are many examples in this forum you should check out. i suggest a small project box for your first build.

 

[jake21]

i can make u a complete module with driver for 35.00 that will include a rkcstr driver set at 125ma or what ever u prefer and soldered to the 803t diode and tested

 

[GooeyGus]

You don't necessarily need a complete full driver, but AT MINIMUM you need some resistors to reduce current, or else it will just die instantly.

 

[AdamR]

You don't necessarily need a complete full driver, but AT MINIMUM you need some resistors to reduce current, or else it will just die instantly.

Isn't the point of the driver to protect the diode from the all famous electrical surge when you press the power button? No resistor on it's own will protect against that.

 

[GooeyGus]

[quote author=GooeyGus link=1240199785/0#7 date=1240281528]You don't necessarily need a complete full driver, but AT MINIMUM you need some resistors to reduce current, or else it will just die instantly.

Isn't the point of the driver to protect the diode from the all famous electrical surge when you press the power button? No resistor on it's own will protect against that.[/quote]

Yeah, it can happen with a dedicated power supply, not as much with batteries. I mean, dont get me wrong I still recommend he uses a driver, but if he is trying to do it on the super cheap he can use some resistors.

ALSO, usually a capacitor it used to prevent voltage spike, BUT I strongly believe that this output capacitor has KILLED far more diodes that it has saved, that's just my opinion though  

 

[FireMyLaser]

One good reason to use a constant current driver, and not a resistor; is to prevent thermal runaway in the diode.
I.E. as the diode heats up, the forward voltage goes down, and so pulls more current, thus making even more heat, till it dies.

 

[Bakawun]

Okay thanks everyone for all the input!

I'm going to go ahead and make sure that I use a good driver as well as a heatsink . If anyone knows where I can get the diode/driver for a good price (for one of the PHRs or 6Xs), let me know!

Best, Philip

 

[john_lawson]

jake or drew diode ryan (rkcstr) for driver