Experimental Study and Implementation of Industrial or Home Automation

Abstract

A telephone circuit which enables switching ON and OFF of appliances through telephone lines. It can be used to switch on or off the appliances from any distance, overcoming the limited range of infrared and radio remote controls. The DTMF signals in telephone instruments are used as control signals. The digit # in DTMF mode is used to toggle between the appliance mode and normal telephone operation mode. Thus the telephone can be used to switch on or switch off the appliances also while being used for normal conversation. In order to build a telephone operated remote switch, first DTMF signal is converted into BCD form with the help of IC MT8870. The DTMF signal in telephone instruments used as the control the digit # in DTMF mode is used to toggle between the appliances mode and normal telephone mode with the help of IC 74LS154 decoder and according data is stored in D-latch. In similar fashion, the relay is operated which causes the appliances turn ON o