Theft detection method and apparatus in which the decay of a res

Details Theft detection method and apparatus in which the decay of a res Theft detection method and apparatus in which the decay of a res

1981-10-23

1984-10-09

Swann, III, Glen R.

Communications: electrical

Condition responsive indicating system

Specific condition

343 68LC, G08B 1324

Patent

active

044764596

ABSTRACT:
In an electronic theft detection apparatus the passage of a resonant circuit wafer 16 through an interrogation zone formed by transmitter and receiving antennas (30, 90) (32, 92) is detected by generating sharp pulses of electromagnetic energy to cause the resonant circuit wafer to resonate for a duration following each pulse. A receiver is provided with a switch (54), signal accumulators or filters (56 and 58) and a comparator (60) to sense the decay of the signal from the resonating wafer and to activate an alarm (36) when that decay occurs at a predetermined value.

REFERENCES:
patent: 2812427 (1957-11-01), Magondeaux
patent: 2899546 (1959-08-01), Hollmann
patent: 2958781 (1960-11-01), Marchal et al.
patent: 3117277 (1964-01-01), de Magondeaux
patent: 3373425 (1968-03-01), Barischoff
patent: 3740742 (1973-06-01), Thompson et al.
patent: 3810172 (1974-05-01), Burpee et al.
patent: 3836842 (1974-09-01), Zimmermann et al.
patent: 3911534 (1975-10-01), Martens et al.
patent: 3919704 (1975-11-01), Williams et al.
patent: 4135184 (1979-01-01), Pruzick
patent: 4215342 (1980-07-01), Horowitz
patent: 4242671 (1980-12-01), Plows
patent: 4321586 (1982-03-01), Cooper et al.

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