发明名称 |
RESONANT CIRCUIT DETECTION, MEASUREMENT AND DEACTIVATION SYSTEM EMPLOYING A NUMERICALLY CONTROLLED OSCILLATOR |
摘要 |
An apparatus for measuring electrical characteristics of a resonant circuit without physically contacting the resonant circuit. The EAS system includes a numerically controlled oscillator for generating an alternating electric signal, the frequency of the alternating electric signal varying in accordance with a numerical frequency control signal; a transmitting antenna connected to the numerically controlled oscillator for establishing an electromagnetic field within a measurement zone; a receiving antenna for sensing disturbances to the electromagnetic field within the measurement zone; a receiver for receiving signals from the receiving antenna representative of disturbances to the electromagnetic field and for determining the Q and center frequency of the resonant circuit; and a clock having a substantially fixed frequency connected to the numerically controlled oscillator. The frequency of the alternating electric signal is restricted to being an integer multiple of an integer sub-multiple of the clock frequency. |
申请公布号 |
EP1181677(A4) |
申请公布日期 |
2005.05.25 |
申请号 |
EP20000935922 |
申请日期 |
2000.05.11 |
申请人 |
CHECKPOINT SYSTEMS, INC. |
发明人 |
RUBIN, STUART |
分类号 |
G08B13/24;(IPC1-7):G08B13/24 |
主分类号 |
G08B13/24 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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