The RCA integrated circuit used in this control is uncommon today. The circuit is from an Electronics Now from July 1995. The sensor determines the value of the adjustment potentiometer.
This traditional configuration of astable was found in a 1965 documentation. Transistors can be...
This variable frequency oscillator generates signals that have a recurrence frequency determined by...
This is an old circuit, using operating equipment of the time, modern operational amplifiers can...