Suggested by National Semiconductor in documentation from the 90s, this circuit makes use of an operational of the time. The configuration can be applied to modern equivalent components
Waking up to a loud and clear sound from an audio oscillator, after up to 5 hours of sleep, or...
This circuit was found in a publication from the 90s. The circuit can be assembled with modern...
This conventional oscillator with the 741 can be precisely adjusted to produce a 400 Hz signal. The...