The sound of drums can be obtained with these two touch-triggered double-T oscillators. The circuit is from a Radio Electronics Special projects from 1993.
In the figure we have the way to connect 6 solar cells in order to obtain higher voltage and...
This circuit has a maximum frequency of 10 kHz and a linearity better than 0.01%. The circuit is...
This circuit was obtained in a 1961 magazine, but it can be easily assembled today, as the...