I. FIELD OF THE INVENTION
The invention relates generally to a metal discriminator, and specifically to a discriminating circuit including a sense coil and means for measuring a change in the self inductance of the coil caused by a metallic object placed substantially in the center of the coil.
II. RELATED ART
Previous discriminator systems based on the principle of applying pulsed signals into a sense coil and measuring the loss in voltage potential across the coil versus time that occurs in the coil after the pulse is applied are known. However, these systems tend to be very sensitive to external noise sources and are subject to temperature sensitivity and physical parameters such as cable length.