I am using an LM317T, trying to use it to create a constant 5v output. I've wired it from the diagram shown here. I am using a pot trimmer to control R2. As far as I can tell, it's wired properly (checked a few times).
What's happening is; if the input voltage is above 5v, it will limit the voltage to 5 volts. But if the input voltage goes below 5v, so does the limit voltage. It seems that it is creating a cap instead of a constant. It's capping the voltage to 5v, but when I go below 5v, it mirrors whatever the voltage is.
Is there a common mistake that I might be making? I've made this circuit before with success, but I think I was using an LM317 instead of the LM317T. Would this make a difference?