Originally Posted By: tfabris
According to Peter's schematic, that looks to me like I've got 3.3v sitting on both the VIN and VOUT sides of that little 2.5v voltage regulator ("U4") on his board, regardless of which position I set the "smd_2_pole_switch" to.

Why does this work without any apparent ill effects?

Somebody else will have to answer that one! smile