Sony PC with 10.5V charger

 the charger is marked as 10.5V 3.8A

but measure with meter, it shows 11.5V

I was plan to use PD type C, but some charger does not provide 12V

so , I have to set for 15V, if the charger only top 12V, it will delivery 12V.

then use a DCDC to switch down to 11.5V

The first I used is this small one, but it turn out very hot at about 2A load.

so a larger module is necessary:

with thing connected in a 3D print box, it does not save me much room...

So, what for?