With this system you can disconnect phone lines in case of need for protection. The circuit is from a 1989 documentation working only with analog lines.
This circuit was found in old documentation and can be implemented with other operational...
This circuit was found in the December 1984 issue of Radio Electronics magazine. The circuit has a...
This Testa o Croce (name in Italian) was obtained from an Italian magazine in 1994. The circuit can...