The operational amplifier used in this circuit is uncommon nowadays. We obtained this circuit from documentation from the 1980s, but it can be adapted to use more modern equivalents.
This is the single-sourced version of the previous oscillator. Frequency can be changed by...
This is a commercial circuit found in Radio Electronics magazine from September 1960. The circuit has...
This circuit is from a 1998 Poptronics. The circuit triggers a buzzer after a certain time, waking...