Equivalent operational amplifiers can be used on this crystal-controlled oscillator. The circuit is from old documentation and can be changed to operate on other frequencies.
In the figure we have the way to make the three-phase control of a motor using opto-diacs. The circuit is...
This circuit was obtained in a 90s Popular Electronics. It is used for tuning on AM radios. The...
We found this circuit in the May 1972 issue of Radio Electronics magazine. Its purpose is to teach...