Hi everyone,
I am new to this forum so please spare me if I say anything wrong.
I have one green aiming laser. The power supply that I got with it is giving out pretty bright light. I wanted to minimize its intensity by controlling the voltage using the DAC of arduino due.
I know that the LM317 voltage regulator has the adjustable output voltage and that it can be controlled with the potentiometer.
I also read some stuff online and understood that LM317's output voltage can be controlled using DAC and so I built the following circuit and observed that I was actually able to control the the output circuit using DAC. However the DAC voltage to Output voltage relationship is not linear and the brightness of aiming LASER is not linealy increased or decreased.

Do you have any suggestion on improving the circuit. Or is there any other way for controlling the voltage using DAC?

I found that digital potentiometer is one way to get the desired variable voltage, however I fear that putting resistance in series with my aiming laser will increase the input current to it and thus it might harm my LASER!!

Please help!! Thanks!!

 

I understand that you have a laser module, not a laser. In laser modules, measures have been taken to stabilize the output power of the radiation. Trying to adjust the output power by adjusting the supply voltage you are struggling with the laser driver. If you make your driver, then you will have the best adjustment possibility. But also you will have more chances to destroy the laser!

 

I understand that you have a laser module, not a laser. In laser modules, measures have been taken to stabilize the output power of the radiation. Trying to adjust the output power by adjusting the supply voltage you are struggling with the laser driver. If you make your driver, then you will have the best adjustment possibility. But also you will have more chances to destroy the laser!

I have gone through the datasheet of the LASER module and I am operating well under the voltage and current limits!! Are there any other factors which I should take care of for saving my LASER from getting harmed?

 

Laser modules do not like to bounce voltage. For example, when the voltage disappears, and then quickly fed.