METAL DETECTOR Russian patent published in 1998 - IPC

FIELD: location of current-carrying and ferromagnetic objects with use of induction coils. SUBSTANCE: metal detector includes reference and retunable generators, mixer and indicator. The latter is manufactured in the form of network of n light guides arranged in the form of ring or line creating effect of " running light " and additionally includes counter-decoder with n outputs to which light guides are connected , delay element, scale-of-n divider, flip-flop and light inhibition element. In this case output of retunable generator is additionally connected to counting C inputs of counter-decoder and scale-of-n divider. Output of mixer is connected to input of delay element and setting input S lop. Output of delay element is connected to reset input R of scale-of-n divider which output is connected to reset input R of flip- flop which direct input Q is connected to reset input R of counter-decoder and to input of light inhibition element which output is connected to common wire of light diodes and inverse output Q of flip-flop is connected to count inhibition input of counter- decoder. EFFECT: simplified information processing circuit, provision for effective inertia-free indication not limited by bounds of device scale, convenient adjustment of sensitivity within wide limits and capability of usage in dark and under water. 2 dwg