The project is designed to keep up secrecy among four parallel telephones associated with a single telephone line. At the point when in excess of one telephone is associated with a single telephone line, anybody can lift a telephone to hear the conservation on the other one. The proposed framework gives an answer for the secrecy among the telephones connected.
In order to meet the end goal to meet this requirement, we are utilizing 4 phones associated in parallel through a single telephone line with each phone associated through a relay in the framework. At the point when any of the phones is lifted every single other telephone are disconnected by the transfers through an arrangement of opto-couplers, the yield of which is sustained to a programmable microcontroller of 8051 family.
The microcontroller sends a signal to a 7 Segment show to show which phone is lifted, while different phones are separated by the particular transfers with help of a Relay Driver IC interfaced to the microcontroller.
This Project can be utilized as a part of houses and offices where in excess of one phone is associated in parallel through a single telephone line. The undertaking is reasonable for both approaching and outgoing calls. Promote the task can be upgraded by including more number of telephones with a radio office. An incoming caller id office can likewise be added to it.