In the figure we have 3 oscillators with logic gates that can be triggered by external logic signals. The circuits were found in the Radio Electronics magazine of April 1987.
This amplifier for automotive use was found in the SGS manual of linear integrated circuits of...
This circuit was found in documentation from the 70s. We can try current JFET transistors....
This circuit makes use of a thermometric sensor that heats or cools according to a current of air....