Theft detection apparatus using saturable magnetic targets
作者： Michael Nelson Cooper
DOI:
关键词: Electrical engineering 、 Dipole antenna 、 Monopole antenna 、 Antenna (radio) 、 Acoustics 、 Physics 、 Transmitter 、 Antenna tuner 、 Directional antenna 、 RLC circuit 、 Electronic circuit
摘要: An electronic theft detection apparatus for of saturable magnetic targets has transmitter and receiver antennas formed single turn loops rigid metal pipe. The are rectangular have a width, in the direction passage, through interrogation zone, less than length shopping cart. antenna is form loop same overall size configuration but bisected with conductor to two balanced loops. purely inductive series resonant circuit inductively coupled into parallel out antenna. Special circuits also provided temporarily disabling when related lower harmonic frequency signal decreases amplitude.
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