Laser driver help!

[deltawars]

I have made a lm317 current driver(Thanks to Daedal's handy tutorial)it puts out 1.5a just what i need but the voltage output is 3.0-3.5v and the laser diode i have says Typical operation voltage is 2.2V and Maximum operation voltage is 2.5V so does anyone know a way i can drop the volts to around 2.5v? I was thinking use a diode but i don't know one with a low current drop.

I used the lm317 on the free laser diode and output voltage was 7v so why didn't it blow?

Also i am using a UltraFire LC 18650 2400mah 3.7v .
(Link to laser diode:One extra high burning power (1000mW-1500mW) 808nm TO-5 9mm laser diode + Gift* | eBay)

All help apreciated -Ethan

 

[Fiddy]

Its a constant current regulator, that means it will manipulate the voltage to maintain constant current to the laser diode, dont worry about load voltage, its all about current with lasers as they are current devices.

Secondly, WHY THE HELL ARE YOU USING A IR DIODE?

 

[deltawars]

Well it was the cheapest high powered diode i could find i didn't want to splash out loads of cash on my first build in case i messed something up and whats wrong with ir?

 

[Fiddy]

Its almost invisible so you wont see where the dot is but will destroy eyes just as quickly as visible lasers, do you have safety glasses for the IR spectrum?

 

[deltawars]

yes they first one of the first things i bought.

 

[Fiddy]

Oh really? which pair did you buy?

 

[deltawars]

I got these 405nm 445nm 450nm Blue 808NM 980NM IR laser protection glasses goggles OD4+ | eBay not sure if there any good tho :/