发明名称 |
INTERFACE CIRCUIT AND MAIN DEVICE |
摘要 |
<p>A port of a main device having a telephone exchange function is provided with an interface circuit to which a telephone or intercom can be connected. The interface circuit is provided with: a feed circuit for supplying required power supply voltage in accordance with a telephone or intercom connected to the port; and a state detection circuit which, if a telephone is connected to the port, detects whether the telephone is in an on-hook state or an off-hook state on the basis of the value of the input impedance of the telephone, and if an intercom is connected to the port, detects whether the intercom is in a standby state or a state in which the activation button is pressed on the basis of the value of the input impedance of the intercom.</p> |
申请公布号 |
WO2012096027(A1) |
申请公布日期 |
2012.07.19 |
申请号 |
WO2011JP70020 |
申请日期 |
2011.09.02 |
申请人 |
NEC INFRONTIA CORPORATION;ITOH, TOSHIHIKO;MASUMOTO, SEIJI |
发明人 |
ITOH, TOSHIHIKO;MASUMOTO, SEIJI |
分类号 |
H04Q3/58;H04M9/00;H04Q3/42 |
主分类号 |
H04Q3/58 |
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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