With this circuit it is possible to receive and send audio signals simultaneously over the same telephone line. The circuit was found in an Elektor from the 90s. The power supply is symmetrical.
Found in American documentation from the 1970s, this circuit employs an integrated circuit from...
This circuit was obtained in the publication 101 Electronics Projects of 1979. The circuit can be...
This assembly circuit using a small motor as a generator was found in Radio Electroics magazine from...