| 摘要 |
An electronic article surveillance tag comprises an electrical power source, receiver circuitry for receiving coded messages for diverse state dispositions of the tag, decoder circuitry for decoding received coded messages and for directing the tag into active and inactive states, alarm circuitry for providing audible output indication of unauthorized activity in respect of the tag in an active state thereof, and motion detector circuitry operative upon disposition of the tag in an inactive state for lessening drain on the electrical power source and further operative on detecting movement of the tag when in the inactive state to dispose the tag in an active state with increased drain on the electrical power source. The alarm circuitry and the motion detector circuitry share common electrical circuit elements, inclusive of a piezoelectric unit.
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