We found this circuit in the Radio Electronics magazine of May 1977. The circuit has the frequency given by the components according to the formula next to the diagram.
This circuit was found in a 2006 publication. It uses discrete components and CMOS that are still...
The sensor of this circuit is a common diode, and the measured range is from -10 to + 40º C. The...
The circuit presented was found in the Linear Applications Handbook of the National Semiconductor of 1994....