DIY Homemade laser diode driver

[Trucky]

Hi,
I share my PCB image with you!

 

[paulkruger]

Perhaps stated elsewhere here but I may have missed it..sorry.

LM350 is functionally equivalent to the LM317 except it can handle 3 amps. Cost only a few cents more so worth it both because you can drive more current and even for lower power LD's running it way under rated capacity means it will run cooler and longer.

 

[paulkruger]

You can get close to the needed value with fixed higher wattage resisters and parallel your lower wattage pot to "fine tune" the output. The total power will be passed via the total parallel resistance, taking some of the load off the pot. Try to configure your pot so it's resistance value will be higher than the fixed load because electricity likes the path of least resistance so if you have a lower value on your pot more current will go through that than through the bigger resisters. R in parallel will result in a total resistance lower than the lowest resister.

Here is a handy calculator: CLICK

 

[paulkruger]

Be sure NOT to go by this images as presented. It has a nice photo of the LM317 but the pin connections as shown are not correct.

Pins left to right are:

1 = ADJ
2 = Output
3 = Input

 

[Just4FunReally]

Be sure NOT to go by this images as presented. It has a nice photo of the LM317 but the pin connections as shown are not correct.

Pins left to right are:

1 = ADJ
2 = Output
3 = Input

Double-posting is frowned upon here. Triple-posting is even worse. If you need to add more information to your previous submission and nobody else has posted yet, edit your last post. Please delete your to other posts and edit the info into your first.

 

[Thrashingentity]

Hello. I have a Question... Being fairly new to "Laser play" Ive recently done lots of research, and know almost all the components and the parts they play on the Driver circuit... EXCEPT the 1N4001 silicone Diode:undecided:. WHAT is the function of this diode and WHY (in the Driver Circuit listed on the first page of this forum) Is it place in that particular location (Crossing positive and negative wires)?
Any help is much appreciated:bowdown: I HAVE ATTATCHED A GIF FILE WITH THE WIRING DIAGRAM AND DIODE/LOCATION IN QUESTION
I'll be practicing on some basic 5mW Red Laser Diodes (because they are cheap). But once I am confident Im gonna custom build a burner "GUN" with a (808nm 300mW High Power Infrared Laser Diode) AND a 5mW Red Laser pointer:evil:
:thanks:
Thrashingentity

 

[Trevor]

Reverse polarity protection, to prevent the laser from dying if the battery is inserted the wrong way.

Trevor

 

[Thrashingentity]

@ Trevor: THANK YOU