Telephone Call Recording Circuit Circuit

Posted on Dec 21, 2012

The dc voltage present on a telephone line is usually around 45 to 50 V on-hook and 6 V off-hook. This circuit uses This drop in voltage to activate a relay. The relay controls a cassette tapeTecorder.

Telephone Call Recording Circuit Circuit
Click here to download the full size of the above Circuit.

Audio is taken off through a network to the microphone input of the cassette.

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