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Circuit operation is as follows. When the phone is on hook the voltage across the phone line is about 48volts dc. When the phone is off hook the voltage will drop to below 10volts dc. When the line voltage is at 48volts the FET is off which causes Q2 and Q3 to be off. When the phone is picked up the FET turns on along with Q2 and Q3 which turns your recorder on. The tape recorder must be in the record mode at all times. As you can see the power source for the circuit is the phone line.

  

hi.............I am Engineering student & I want to make a project for summer.....ur  project is attractive, so plz send me the complete discription and  cct diagram of this.........thnks in anticipation..wating,,,,,,,,,,,plz mail to mudassir_lovely@yahoo.com,capricorn_ask4u@hotmail.com

  

send me detail of this project my id is moradiya_1989@yahoo.in

  

please can u send the circuit and other details to sargpro@gmail.com

  

hi

    my name is akeef & i m currently pursuing my b.tech . i m very much interested in electronics& i heared alot of u .

 

    i need to submit my miniproject  ,which i want to do on communication,as i am an ECE student...pls reply me as early as possible.

                                 thank you 

                                                                            yours faithfully

  

sir,

plz send me the full project details in my id tuhindisha@gmail.com