We found this circuit that converts a direct voltage into a proportional frequency signal. The circuit is from an Electronics Now from April 1993. The JFET can be of any type.
This circuit is from a 1991 publication, but it can be assembled with more modern components. We...
This circuit provides a current given by the components calculated according to the formula next...
Published in Radio Electronics in October 1963, this circuit increases the audio output of a small...