Two line intercom


Posted on Apr 5, 2012

The circuit presented here can be used for connecting two telephones in parallel and also as a 2-line intercom. Usually a single telephone is connected to a telephone line. If another telephone is required at some distance, a parallel line is taken for connecting the other telephone. In this simple parallel line operation, the main problem is loss of privacy besides interference from the other phone. This problem is obviated in the circuit presented here.


Two line intercom
Click here to download the full size of the above Circuit.

Under normal condition, two telephones (telephone 1 and 2) can be used as intercom while telephone 3 is connected to the lines from exchange. In changeover mode, exchange line is disconnected from telephone 3 and gets connected to telephone 2. For operat




Leave Comment

characters left:

New Circuits

.

 


Popular Circuits

Nicad-batterv-protection-circuit
Air Quality Monitoring System
200W Stereo High Power Amplifier LM3886
radio circuit diagram
Battery charging indicator circuit
Antenna Tuning Unit
Automatic Windshield Washer Control
Frequency meter with 10Hz to 2MHz
I2C control interface includes RGB LED Driver circuit
On-off control circuit diagram
LC189 making decorative lanterns with fans



Top