专利快速检索-快速检索全球专利，免费商用专利数据库-IPRDB

1. 发明专利

JPS62210770A TALKIE SERVICE SYSTEM 失效
公开(公告)号：JPS62210770A
公开(公告)日：1987-09-16
申请号：JP5251986
申请日：1986-03-12
申请人： HITACHI LTD , NIPPON TELEGRAPH & TELEPHONE
发明人： SHIBATA SHOGO , HISAMURA MAKOTO , OCHI HIDEKAZU
IPC分类号： H04M11/08 , G10K15/02 , H04H20/81 , H04M3/42 , H04M11/06
摘要： PURPOSE:To perform a talkie service utilizing a telephone line without injuring the convenience of a telephone, by supervising continuously a line by permitting a micro current by which no vacant call detection is affected in the line, to flow, on the line in the talkie service. CONSTITUTION:When control parts 7 and 14 detects the vacant state of the telephone line with the outputs of potential monitoring parts 5 and 10, a talkie sending part 6 on a talkie service station device 3 is connected to a talkie amplifier 12 in a talkie service customer station equipment 8. When an incoming from a telephone exchange 1 arrives in a talkie service serving state, the relay and the earth of a subscriber's circuit 2 are separated from the line as known well, and potentials go to the potential polarities of a line A (ground) and a line B (-48V) by input trunks not sown in figure. Changes in the potentials are monitored at the potential monitoring parts 5 and 10 respectively in the station device 3 and the customer station equipment 8, and the control parts 7 and 14 restore relays S in line switching parts 4 and 9, thereby the talkie service is interrupted.

IPRDB

热门服务

关于我们

友情链接

联系方式