This simple intercom for home use was found in a 1979 publication. It can be easily mounted with BC548 transistors instead of the originals. It will be interesting to use a source instead of a battery. High impedance speakers can be replaced with low impedance types but connected to the circuit using a small output transformer of the type found in transistor radios. The remote unit must not be more than 20 meters away and the cable does not have to be shielded.
| Clique na imagem para ampliar |
