Telephone Controlled Switch

[aruljothi]

  Telephone Controlled Switch implies control of devices at a remote location via circuit interfaced to the remote telephone line/device by dialing specific DTMF (dual tune multi frequency) digits from a local telephone. Using this system the user can access any load from a remote location. Each load will be given a code number. All he has to do is dial the corresponding code through a local phone.

This system can selectively turn on or off multiple loads one at a time or switch off all the loads simultaneously. It also provides you feedback when the circuit is in energized state and also sends an acknowledgement indicating action with respect to the switching on of each load and switching off of all loads (together). This is a micro controller aided system where a ring detector, auto lifter and DTMF decoder work together to place a call and a relay driver connects the required load. This makes the task of the various operators easy as they can sit anywhere and control the status of the various loads.
In the existing system if an operator in and industry has to control a certain load there is no other method than being physically present at the site of the load. If he has to switch off a system after a particular period he will have to wait till the completion of the operation. But our project titled "Telephone controlled switch" rectifies this disadvantage of conventional systems. This system as its name suggests help the user to control the status of various loads from any remote location through a telephone connection.

As mentioned this system implies control of devices at a remote location via circuit interfaced to the remote telephone line/device by dialing specific DTMF (dual tune multi frequency) digits from a local telephone. For this each of the loads that the operator intends to control is given a code number and is connected to the telephone line through relay drivers and micro controller. So when the user dials the respective codes the corresponding loads can be accessed. Then its status can be controlled using some other code. All this is made possible by programming the micro controller.

This project telephone controlled load activator has the following features.

1. It can control multiple load (on/off/status of each load)

2. It provides you feedback when the circuit is in energized state and also sends an acknowledgement indicating action with respect to the switching on of each load and switching off of all loads (together).

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