When your local electronics store only carries 12v fans...

When your local electronics store only carries 12v fans…

I’ve done the very same thing, but for a much larger fan pointed at my driver ics. I’ve got a 7812 cable tied into the path of the fan.

two of them in series seems another possible choice

Yep, 2 wired in series would work fine while waiting for 24v fans. @SMW3D , Amazon and Makers Tool Works has’em

That’s legit, but be careful touching the regulator when using it with some fans. Putting the heat sink in the air flow probably helps though,

I want to draw up a board that does better, it would have a switching converter plus FET gates so the controller can PWM the reduced voltage.

If you’re going to try two fans wired in serial, make sure that their identical. They won’t get 12V each if they have different resistances.