I am wondering if I should use an LM317 or LM1117 for a 5v circuit that needs 3.3v for a sub-circuit far (20ft) from the power supply.
Any help would be greatly appreciated. Thanks in advance.
Use a LM1117 for the following reasons:
Where Vloss is the voltage drop caused by the resistance of the cable.
In terms of efficiency, they are both linear regulators so the wasted power in each will be roughly the same.