R.F. suppression technique for collective objects management system using R.F. object identification

In a system for managing objects distributed in an object location space, said system comprising a plurality of receptacles for a plurality of objects, each of said receptacles having a pair of electrically conductive members;

• a plurality of pairs of electrically conductive signal leads each coupled to a different one of said plurality of pairs of electrically conductive members, each of said plurality of pairs of electrically conductive signal leads being coupled in parallel to a common signal input terminal;
• and a plurality of r.f. circuits each associated to a different one of said objects, each of said plurality of r.f. circuits having a pair of electrically conductive terminals in electrical contact with one of said plurality of pairs of electrically conductive members when the associated object is located in one of said receptacles, a crystal resonant at a specific frequency and an indicator activated whenever the associated crystal detects an r.f. signal at the specific frequency of that crystal, the resonant frequency of each of said crystals being different from the remaining ones of said crystals so that an r.f. signal applied to said common input terminal causes only one of said plurality of crystals to resonate and only the associated indicator to be activated;
• the improvement wherein each of said plurality of r.f. circuits includes a latch having an input coupled to the respective crystal and an output coupled to the associated indicator, said latch being responsive to the resonant state of said crystal for activating said indicator and for providing a resonant state feedback signal for terminating said r.f. signal.