Help with laser driver with LT317AT

[Tordentor]

Hi Everybody,
This is my first time to post anything on here.
I need help (schematic) to make a laser driver with a LT317AT.
I need it for powering a laser diode I took out of a DVD/CD ROM drive (I know its not going to burn anything, that's ok) It is out of a model XJ-HD166S drive (I don't see any manufacturer but I found it online when I googled that)
I would like to be able to run it off of 4.5v.(If that's possible)
Please don't tell me to go google it, I have done that and all the schematics I find use the LM317 and I am not sure what changes to make for the LT317AT to fit in.
Also any help on the pinout of the diode would be appreciated, it is a closed can type with four leads at the bottom three of which are insulated from the can by the little black rings. It was the only diode on the sled so I assume it is a combo IR/Red diode, I would want to use the red part (unless ofcourse hooking both up would raise the power output and enable it to burn, any thoughts on that guys?)
Thank you all, any help is appreciated.

 

[marcuspeh]

Re: Help with laser driver with LT317A

First of all, you will need goggles before you do start with the laser.

I would like to be able to run it off of 4.5v.(If that's possible)

I will not run it at 4.5v but at around 2.2v to 3v with a current of around 50mA. 4.5v will definitely fry your diode.

any help on the pinout of the diode would be appreciated, it is a closed can type with four leads at the bottom three of which are insulated from the can by the little black rings.

This should be the pins that you need
https://www.dropbox.com/s/ftzmj9itzru92rx/4 pin.jpg?dl=0

 

[Tordentor]

Re: Help with laser driver with LT317A

I will not run it at 4.5v but at around 2.2v to 3v with a current of around 50mA. 4.5v will definitely fry your diode.

I was thinking of 4.5v as the input to the circuit with ofcourse the proper diode voltage as the output. 2.2v at 50mA is 110mW, is that not too much for this diode considering it is only a low power one from a DVD Reader? Can anybody help me make a circuit to power it using the LT317AT(considering that this one is different from the LM317) as the voltage/current regulator if it's needed(and if its possible)
:thanks:

 

[marcuspeh]

Re: Help with laser driver with LT317A

I was thinking of 4.5v as the input to the circuit with ofcourse the proper diode voltage as the output. 2.2v at 50mA is 110mW, is that not too much for this diode considering it is only a low power one from a DVD Reader?

Ops, i didnt realise it is a dvd reader. Since it is froma dvd reader, it is relatively weak, i would run it with around 10-20mA

 

[Tordentor]

Re: Help with laser driver with LT317A

Ok :thanks:
Anybody know if I can use the LT317AT for a driver to get the 2.2v at adjustable ca.1-30mA output with 4.5v input(3 AAA batteries)?

 

[Tordentor]

Just saw something. It says AN3w on the base of the laser diode I have if that helps any. Thanks