Cut Phone Line Detector

Posted on Oct 19, 2012

A while ago I got an email asking for the schematic of a circuit to detect cut phone lines. It didn`t take me long to find this circuit in Electronics Now. When the circuit detects that a phone line has been cut, it activates a MOSFET which can be used to drive a relay, motor, etc. It can also be connected to a security system.

Cut Phone Line Detector
Click here to download the full size of the above Circuit.

1. The "Load" can be a relay, lamp, motor, etc. The circuit can also be connected to a security system to sound an alarm in case the phone line is cut. 2. If the circuit is connected to a security system or other circuit, both circuits must b

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