I did a DIY a portable monitor from a salvaged laptop LCD screen using a controller board I ordered online. Managed to make it work with a power adapter and an HDMI cable. I want to use it with my laptop but here's the thing. My laptop has a USB type C charging port with a 12V 3A brick. I'm trying to figure out a way to power both laptop and DIY monitor with just that one brick.
My initial plan was to look for a Y-cable with USB-C female split into USB-C male and USB-A male (or micro), and splice the DC jack to the USB-A for the DIY monitor, but I cannot find such a cable anywhere online or in stores. So I thought maybe I can use a short USB-C male to USB-C female extension cable and splice the DC jack to the wires in the extension cable.
Before I do any purchasing, I'd like to know would it be possible to accomplish this? Will there be enough current to power both devices? Is there another or better way to go about this issue?