This circuit was obtained from Dutch documentation from 1964. The components are of the time, but current equivalents such as BC548 to BC108 can be used.
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...