Found in Popular Electronics from the 1990s, this variable frequency circuit generates signals in the shortwave range. FETs admit equivalents.
The frequency of this circuit depends on the capacitor. The unijunction transistor can be the...
We found this interesting effect circuit for LEDs in a 1993 publication. The circuit uses very...
This circuit from a 1980 publication, converts the temperature sensed by Q1 into a frequency in a...