Book excerpt: Pulse induction metal detectors are very sensitive to ferrous (iron) targets, and one that can ignore iron has been a sort of holy grail for metal detector developers for some time.The Voodoo Project is a written record of the author's personal mission to design and develop a working pulse induction (PI) metal detector that is capable of good iron rejection.Voodoo is a hybrid detector that has features of both a PI and a VLF. The design goal was to develop a PI that can be used both inland and on the beach. In particular, special attention was devoted to finding non-ferrous targets in areas infested with ferrous trash. Rejection is not based on target conductivity, as Voodoo provides true ferrous/non-ferrous discrimination.