Automatic recording telephone interface circuit

Posted on Mar 28, 2007

Automatic recording telephone interface circuit as shown, the circuit has an automatic answering and recording function (need to reprovision or small solid state recorder recor

Automatic recording telephone interface circuit
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ding chip), the circuit is simple, the quiescent current of less than 20 A, an external lead connected to the external telephone without having to open the phone. IC1 is Optocouplers: IC2 (4017) decimal counter/divider, when the end of the fourth ring, ? feet high output behind the trigger circuit; IC3 speech circuit, there is not the owner, please brief leave a message. Junior B with µ0.1mm wire around 350 turns, secondary winding enameled with µ0.07mm 1000 turns.

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