We found this circuit in documentation from the 1980s. The transformer is of the low voltage type with a 1: 3 turn ratio and the transistors can be of general-purpose types.
This circuit was obtained in an old American documentation, remembering that the 566 is the double...
With this simple circuit it is possible to simulate a telephone line for carrying out repairs on...
This simple circuit was found in a 1981 publication. As readers can see, we have an H switch and...