We found this circuit in an old documentation, but it is still current. General purpose transistors can be used, and the SCR can be the TIC106. The bell is a transducer with an oscillator (buzzer).
Found in an American documentation from the 1960s, this circuit uses transistors from the time. The...
In the figure we have a typical configuration with operational, which can be different from the...
This limiting circuit or Clipper was found in a 1977 documentation. The circuit uses only passive...