Ionce designed a classic metal detector: it stripped out analog
electronics from IB, for the first time, thus greatly simplifying the circuitry. Vadym Vasylyshyn at Boeing just built one -- and
videoed the whole process. I really like this video. Well done. OBSERVATION: It gives one a good idea, too, what goes into the design of a metal detector. One may view the video on YouTube at Matchless Metal Detector. The original design is at Geotech. There are suggested improvements on this blog -- above all a regulated power supply.