This circuit was found in the October 1989 issue of Radio Electronics magazine. It drives an auxiliary relay with the call signal for a possible louder bell.
This circuit can be used as a rhythmic light or as a control shield for incandescent lamps from...
We found this circuit in a European publication from the 1990s. Transistors are still common types...
Settings like this can be found in this section and on this website, but from different sources of...