Found in a 90s Popular Electronics, this circuit uses a 741 to generate frequencies from 0.1 to 30 Hz. Observe the phototransistor feedback.
This interesting comparator circuit was found in an old Motorola documentation. The integrated circuit...
This two-transistor constant current source is from a 1968 documentation. Modern equivalent...
An interesting application that finds applications in industry, especially when fluctuations in...