Laser with throttle capabilities

[Cyparagon]

You'd also want to put the pass transistor on the other side of the laser diode. It would work as-is if you had 12V input maybe, but it's best practice to put NPNs on the "low side" when possible.

 

[DarthTadpole]

You'd also want to put the pass transistor on the other side of the laser diode. It would work as-is if you had 12V input maybe, but it's best practice to put NPNs on the "low side" when possible.

Cool, I noticed a few schematics on-line my way buy most were the other way. I guess coming from a software engineering background I think "vary the high side and hold the ground 'constant'". But in reality it doesn't matter whether the high or low side if the LD is changed.

 

[Cyparagon]

You can have high-side regulation instead, but a PNP/P-MOS is better suited.