This circuit was found in the November 1974 Radio Electronics magazine. The voltage depends on the supply and the timings of R1 and R2 as well as C1 and C2.
At that time, practical ideas were interesting, and many can still be used today. In the figure we can...
Pressing S1 the LED glows by a time interval depending on the capacitor. Time intervals in the...
In fact, this circuit transmits a signal rich in harmonics without any tuning and can be picked up in a...