Found in American documentation from the 90s, this circuit can be applied to other operational ones. We found it in an EDN of the time. Next to the diagram is the response curve.
This very simple 1-transistor oscillator is from Raytheon's transistor manual of the 60s. The...
This circuit is from a 1957 Raytheon transistor manual. The diode can be of general-purpose...
We have in the figure an ultra-simple alarm found in a 1981 publication. As the author indicates, it is...