Based on a unijunction transistor, this circuit was found in the January 1994 issue of Electronics Now magazine. The frequency range depends on C1, which can be changed.
Using the CMOS 4001 we found this circuit in the October 1974 Radio Electronics magazine. The...
One 4018 is used to divide the frequency of a digital signal by ten as shown here. The maximum...
This 90's project shows how to use an old cassette recorder to practice telegraphy. In position A of the...