We found this circuit in an American documentation from 1947. The circuit uses 5 tubes and has a feature to keep the tube filaments preheated.
This circuit adds a beep to turn on with car flashers that do not have this feature. A 47 ohm to...
In the figure we have the way to simulate an SCR using two complementary general-purpose...
This circuit different from the timer was found in an English publication from 1978. The circuit uses...