I want to construct a tv console with a drop down door, but i want the door to fully retract into the cabinet after it’s dropped down. I’m not sure what type of hinges i need for that. what hinge system can do that?
Cabinet pocket door hardware, is the search term you want. (Retractable door slide may also be helpful)
Other models would work but you would need to ad a cleat on the sides of the cabinet to keep the door from swinging down when retracted. (If used on top)
These are all set up to be on top, (or the side) you state "drop down" I suppose you could use them in that orientation. The 1234 or the 1312 would work for that application.
Here is a Accuride Youtube video showing all of those models.
There are many options, but this should point you in the right direction.
You could try something like this.