buck_converter_case

This is a case for a "buck converter" high efficiency DC - DC converter. The ones I use are around $1 and are LM2596 based. They take in 4-35 volts DC and can output 1.23-30 volts DC (input needs to be around 3 volts higher than the voltage output so 5v in to 2 volts out would work, but 5v in to 4v out would not- input voltage would need to be closer to 7v in.
Search Ebay for LM2596. Try for an auction but dont pay more than $1. Make sure it looks like the picture of the board in the galler