Found in a 90’s Popular Electronics, this circuit generates sinusoidal signals with frequency controlled by an input signal. C4, C3 and C1 together with R12 and R3 determine the frequency generated.
This two-transistor constant current source is from a 1968 documentation. Modern equivalent...
This converter or inverter uses components that are still common. The transformer is the type...
Using a V/F converter this circuit was found in the June 1991 issue of Radio Electronics magazine. The...