Metal Detector

Pulse-Induction Metal Detector
Theta Engineering developed a metal detector which improved on state-of-the-art by reducing power consumption to the point where it would operate for 9 months on a set of D cells, eliminating the necessity for an on/off switch thus preventing its alarm function from being easily defeated. This device utilized a Microchip microcontroller to reduce circuit complexity by replacing circuit functions with firmware. The microcontroller also allowed design flexibility, digital signal processing and additional power reduction techniques to be applied. Small but sophisticated DSP filters were implemented to improve the design's ability to operate in an environment with a high degree of ambient magnetic noise.