(Automatically Mute Your Car Audio System when you receive a
call)
Muting car’s audio deck,
while talking on cell phone is an important yet difficult task. This project is
designed to solve the problem. A sensitive IR transmitter and receiver pair is
designed and fixed to a cell phone holder. Always the cell phone should be
placed in the holder. The transmitter
unit continuously transmits IR rays. These IR rays are interrupted by the cell
phone. Whenever the cell phone is lifted from the holder, the IR rays fall on
the receiver and it sends a signal to switching circuit. A relay is driven by a
relay driver circuit and the relay opens the deck speaker wires and the audio
will be muted. After the completion of
the conservation, the cell phone should be kept back in the holder. Again the
IR rays will be interrupted and the relay will be de-energized. Music will be
played again normally. This project uses
regulated 12V, 750mA power supply. 7812 three terminal voltage regulator is
used for voltage regulation. Bridge type full wave rectifier is used to rectify
the ac out put of secondary of 230/18V step down transformer.
Block Diagram :
