Ambedkar Institute of Advanced Communication Technologies & Research

TELE Remote Control

Today’s telephone network is a complex interconnection of a variety of heterogeneous switching system. Telephone line is very useful for voice and data communication in various applications. The main application of telephone line is for voice and data communications. By using a telephone line we developed a remote control by which user can switch any electrically operated device ON/OFF from any where in the world ;the distance for this remote control circuit is immaterial or in other word, circuit is fully independent of distance. There are two main things in this project, one is telephone line and other is IC’s.

Today’s design of any digital system has become very simple due to use of IC’s. The IC reduces a big part of circuit, IC includes the logic functions, which is hard to implement by using various types of gates. IC’s are made on the very large scale integration technology, a large number of gates are made on a single IC.

Here we try to implement TELE REMOTE CONTROL by using DTMF IC (CM8870) and other group of IC. The DTMF IC work on the basic principal of digital detection and decoding of the control signal coming from the telephone line. The CAMD CM8870/70C provides full DTMF receiver capability by integrating both the band-split filter and digital decoder functions into a single 18-pin DIP package.

The CM8870/70C is manufactured using state-of-the-art CMOS process technology for low power consumption (35mW, MAX) and precise data handling. The filter section uses a switched capacitor technique for both high and low group filters and dial tone rejection.

The CM8870/70C decoder uses digital counting techniques for the detection and decoding of all 16 DTMF tone pairs into a 4-bit code. This DTMF receiver minimizes external component count by providing an on-chip differential input amplifier, clock generator, and a latched three-state interface bus.

The on-chip clock generator requires only a low cost TV crystal or ceramic resonator as an external component. Our project is the combination of telephone and various types of IC’s, resister, capacitance, zener diode etc.

The DTMF IC wait for some rings and then picks-up the phone and does some specified work like switching on the air-conditioner and switching off the refrigerator. The functionality depends upon the DTMF code as specified in the table of this project report. There may be a large number of functions depending on the user. We have assumed LED’s are electrically operated devices; these LED’s are controlled from remote side by using a telephone line. In future this project may be implemented, in its original form.

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