Compact step-up module for 12V DC fan?

It’s not for LED project but for a 12V fan, the typical fans in PC cases.

I was thinking about this module from Banggood, run from a single 14500 or 18650 for weight and size considerations; seems the only one that works from 3V that can output 12V.

But I am sure there must be smaller modules? I have some spare voltmeters already to cover that aspect.

Lastly, is PWM good/efficient for a brushless PC fan?

Oh nice…I only have 2 of the buck circuits (use it to buck 19.4vdc to 13.8 for charging a lead acid battery)

Those look pretty nice

Worse comes to worse a capacitor across the leads going to the fan will lower the ripple of the PWM somewhat

You could even use one of these 5v USB ones, the fan would spin much slower though has stuff (and on discount through end of this month, that is, tomorrow)
Found mentioned on eevblog