Hey aubeynarf think you are talking about something like this.
Its a special usbc-pd to 5.5x2.5 barrel jack with manually selectable voltage. You just plug it into a pd charger and select the voltage of the device. The rest is finding a barrel plug to barrel plug adapter that plugs into your device. Hope this helps.
I want that whole arrangement to be in a tip with a USB-C receptacle and a fixed voltage and barrel size so it’s barely bigger than my thumbnail and can be used with standard usb-c cables.
So I can get a “9V-5.5x2.5-Pos” to convert my casio keyboard to usbc, without all that other stuff hanging off and extra, unnecessary pieces
But yeah that’s cool
If your device happens to be 18-20v you can get a usbc-pd laptop connector with a dc barrel jack output. It has the USBC-PD chip built into it to tell the charger to output 20v and you can probably hunt down barrel adapter bits. Your regular 65-100w rated usbc cord plugs in like anything else.
The other voltages are tough theres not really a consumer market for 15v or 9v specific usbcPD to barrel things.
