In figure 1 we have a circuit that turns on after a certain time and then turns off, also after a second interval.
This circuit was found in a 1967 Delco Radio documentation. The circuit has an input voltage of 250...
This interesting idea of a radio detector for a medium-wave radio is from a 1966 documentation. The critical...
This circuit is from an English publication from 1978, but it can be assembled with BC548 for TR2...