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庄子全文专利名称：DTMF-Code controlled lock device 发明人：Jim Cho
申请号：US07/190367
申请日：19880505
手机插u盘在哪里打开公开号：US04887078A新年快乐祝福词>路上花>那木措湖
公开日：
凉拌核桃肉
萨摩耶狗狗
19891212
专利内容由知识产权出版社提供
摘要：A DTMF-code controlled lock device mainly compod of tow units: a key control unit and a lock-body control unit. The key control unit, adapted to be carried by a ur includes a dual-tone multifrequency (DTMF) encoding circuit with a keyboard and an amplifying circuit respectively connected thereto for inputting and outputting an unlocking DTMF code. The lock-body control unit, adapted to be installed in a door together with a door lock, includes a transducer for transferring the DTMF code signals received from the key control unit, a pair of amplifying circuits connected in ries with the transducer, a decoder with its input connected to the amplifying circuits for decoding the DTMF signals into a BCD code, a CPU with a pair of memory units coupled with the output of the decoder for comparing the BCD code with pre-stored one therein, and a relay circuit coupled with the CPU in connection with the lock bolt for effecting unlocking operations upon being energized by the CPU if the comparison finds the two identical.
申请人：CHO; JIM
代理机构：Ladas & Parry
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